TITLE_XXO QUATERNARY GEOLOGY AND PALEOECOLOGY OF SOUTHEASTERN ALASKA: PROGRESS AND OPPORTUNITIES FOR  FUTURE RESEARCH

AUTHORS_XXO AGER, THOMAS A.

AUTHOR_1_XXO U.S. Geological Survey; tager@usgs.gov

PARAGRAPH_1_XXO The Alexander Archipelago of southeastern Alaska has been largely neglected by Quaternary geologists, perhaps because of logistical challenges, a rainy climate, a dense, jungle-like cover of coastal rainforest and muskeg vegetation, and in many areas, an abundance of brown bears.  However, significant progress in unraveling the late Quaternary history of adjacent coastal British Columbia has been made in recent decades, demonstrating that successful research can be done in spite of the region?s challenging environment.<br>  <br>The U.S. Geological Survey began a research project in 1998 aimed primarily at reconstructing the postglacial history of environmental change in southeastern Alaska,  by means of pollen analysis of cores obtained from peat deposits and lake sediments.  We have also attempted to improve on mapping of the poorly delineated extent of late Wisconsin glacial ice in southeastern Alaska (Ager, 1999; Carrara et al., this volume). Ongoing USGS research on the history of postglacial vegetation development and climate history builds on pioneering studies by Calvin Heusser in the 1950?s.  Heusser conducted a study of the vegetation history of the North Pacific coast from northern California to the Aleutians by studying pollen records obtained by coring peat deposits (e.g., Heusser, 1960, 1985).  From a modern day perspective, Heusser?s  research in southeastern Alaska suffers from a lack of radiocarbon dates for most sites, and the few sites with some age control usually have only a single radiocarbon date.  
PARAGRAPH_XXO During the ongoing USGS research project, 6 lakes and 14 peat deposits have been sampled between Ketchikan and Yakutat, and we are presently analyzing and dating many of these sites. These pollen records will provide a detailed regional vegetation and climate reconstruction for the postglacial. Lake sediment records tend to preserve longer histories than peat deposits, thus we have cored as many lakes as we could.<br> <br>Preliminary results of our USGS study suggests that the major deglaciation of southeastern Alaska occurred between 14,000-13,000 radiocarbon yr B.P. although some ice thinning and retreat may have begun earlier.  Only one site we have sampled penetrates to an early (ca.13,000 yr B.P.) lowland tundra vegetation that colonized newly deglaciated lands in the western fringes of the Alexander Archipelago.  Most sites we have studied thus far indicate that the earliest recorded vegetation following local deglaciation was open pine forest (probably Pinus contorta, ssp. contorta) with an understory composed mostly of ferns.  This vegetation type may have developed as early as 12,500 yr B.P. in some areas.  During the Younger Dryas interval of cold, dry climate (ca. 11,000-10,000 yr B.P.), pine-dominated forests declined as alders (Alnus) spread across much of the region, and Sitka spruce (Picea sitchensis) began to replace pine as the dominant tree species.  Western hemlock (Tsuga heterophylla) and mountain hemlock (Tsuga mertensiana) soon spread across much of southeastern Alaska during the early Holocene.  Early Holocene forests were probably not as dense and as extensive as those which developed in the late Holocene under a wetter climatic regime.  Red cedar (Thuja plicata) and yellow cedar (Chamaecyparis nootkatensis) do not appear to have been well established in southern southeastern Alaska until the late Holocene.<br> <br>A rich record of fossil vertebrates is emerging from cave deposits in karst areas of southeastern Alaska (e.g., Heaton et al., 1996).  Radiocarbon dates indicate that the faunas span more than the last 50,000 years of the late Quaternary.  Unfortunately, the pollen records obtained thus far are mostly younger than 13,000 yr B.P., and therefore the vegetation types associated with the earlier faunas cannot yet be documented.  Future studies may lead to the discovery of older pollen-bearing deposits from the region.  There are a number of areas on the western islands of the Alexander Archipelago that appear to have escaped being overridden by glacial ice during the late Wisconsin.  In those refugia, deposits of late Wisconsin age, and possibly older fossil-bearing sediments may be preserved. Finding such deposits is proving to be a challenging task. 
PARAGRAPH_XXO Recent archeological discoveries in southeastern Alaska and in the Queen Charlotte Islands of northern coastal British Columbia indicate that humans have inhabited the region for at least the past 10,000 years (Dixon et al., 1997; Baichtal et al., 1997; Josenhans et al., 1997).   Additional geological studies are needed to help pinpoint areas where other sites of early occupation by humans may be found, in caves, on isostatically and tectonically raised shorelines, or on the now-submerged inner continental shelf.
PARAGRAPH_XXO There are many areas of southeastern Alaska where there are excellent subjects for future research projects by university-based scientists.  Some topics for research include: (1) refinement of glacial limits during the late Wisconsin and earlier glacial events; (2) studies of Holocene glacial history of mountainous areas of the Alexander Archipelago (e.g., Baranof Island); (3) sonar and seismic imaging of the inner continental shelf to delineate till deposits, moraines, lake basins, glacial river valleys, and other features submerged during postglacial sea level rise; (4) sediment coring on the inner continental shelf to obtain terrestrial and postglacial (marine) paleoenvironmental records; (5) high resolution paleolimnological studies of sediment cores from lakes in the region (e.g., diatoms); (6)  unraveling the complex history of regional postglacial tectonic uplift and isostatic rebound; (7) study of karst landscape formation in a wet, cool temperate environment; (8) searching for evidence of full-glacial paleoenvironments within refugia in the western Alexander Archipelago.

REFERENCE_XXO Ager, T.A., 1999.  Late Wisconsin glacial and postglacial history of southeastern Alaska: Implications for ecosystem development and colonization by humans: Geological Society of America Abstracts with Programs, v 31, no. 7, p. A-367.   
REFERENCE_XXO Baichtal, J., Streveler, G., and Fifield, T., 1997. The geological, glacial and cultural history of southern southeast. In Rennick, P. Alaska?s Southern Panhandle: Alaska Geographic, v. 24, no. 1, p. 6-31.
REFERENCE_XXO Carrara, P.E., Ager, T.A., Baichtal, J.F., and Van Sistine, D., (this volume), Late Wisconsin glacial limits in southern southeastern Alaska, as indicated by a new bathymetric map. 
REFERENCE_XXO Dixon, E.J., Heaton, T.H., Fifield, T.E., Hamilton, T.D., Putnam, D.E., and Grady, F., 1997.  Late Quaternary regional geoarchaeology of southeast Alaska karst: a progress report: Geoarchaeology, an International Journal, v. 12, p. 689-712.
REFERENCE_XXO Heaton, T.H., Talbot, S.L., and Shields, G.F., 1996. An ice age refugium for large mammals in the Alexander Archipelago, southeastern Alaska: Quaternary Research, v. 46, p. 186-192.
REFERENCE_XXO Heusser, C.J., 1960, Late Pleistocene Environments of North Pacific North America: American Geographical Society, Special Publication 35, New York, 308 p.
REFERENCE_XXO Heusser, C.J., 1985, Quaternary pollen records from the Pacific Northwest coast: Aleutians to the Oregon-California boundary. In Bryant, V.M., and Holloway, R.G. (eds.), Pollen Records of Late-Quaternary North American Sediments: Dallas, American Association of Stratigraphic Palynologists Foundation, p.141-165.
REFERENCE_XXO Josenhans, H.W., Fedje, D.W., Pienitz, R., and Southon, J., 1997. Early humans and rapidly changing Holocene sea levels in the Queen Charlotte Islands-Hecate Strait, British Columbia, Canada: Science, v. 277, p. 71-74. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO GLACIATION OF THE TAYMYR PENINSULA, ARCTIC SIBERIA

AUTHORS_XXO ALEXANDERSON, HELENA (1); Hjort, Christian (2); MÑller, Per (3)

AUTHOR_1_XXO (1) Dept of Geology, Lund University, Sweden; helena.alexanderson@geol.lu.se
AUTHOR_2_XXO (2) Dept of Geology, Lund University, Sweden; christian.hjort@geol.lu.se
AUTHOR_3_XXO (3) Dept of Geology, Lund University, Sweden; per.moller@geol.lu.se

PARAGRAPH_1_XXO The maximum glaciation of the Taymyr Peninsula in north-central Siberia (Fig. 1A) probably took place during the Saalian (Illinoian) ice age, when the entire peninsula was ice covered. The resulting deep isostatic downpressing led to widespread postglacial marine inundation, the so-called Boreal Transgression during the Eemian (Sangamonian) interglacial. During the Weichselian (Wisconsinan), three glacial stages of successively decreasing amplitude took place (Fig. 1B). We have mapped and dated these stages by doing fieldwork, interpreting satellite images and using dating methods such as optically stimulated luminescence (OSL), radiocarbon (14C) and electron spin resonance (ESR). 
PARAGRAPH_XXO The glacial geomorphology and drainage systems, the direction of glaciotectonic deformations and the provenance of crystalline erratics indicate that the glaciations affecting the northwestern and central Taymyr Peninsula during the Weichselian were mainly caused by ice sheets coming from the Kara Sea shelf. No sign of any local Weichselian glaciation has been encountered, although the higher easternmost part of the Byrranga Mountains, not studied by us, may at times have acted as a local centre of glaciation.
PARAGRAPH_XXO The most widespread glaciation dates from the Early Weichselian and culminated at c. 100 ka BP. At most the ice-front reached some 400 km inland from the present coast, leaving a series of more or less distinct zones of ice-marginal features south of the Taymyr Lake basin (Fig. 1B). Due to the large glacio-isostatic downpressing, the ice-sheet front retreated in a marine basin, resulting in a series of marine deltas formed at c. 100 m a.s.l. on the southern side of the Byrrangas (Möller et al. 1999). There are no signs of any glaciation reaching south of the Byrrangas after the Early Weichselian and continuous lacustrine/aeolian sedimentation took place in the Taymyr Lake basin (e.g. Pavlidis et al. 1997, Möller et al. 1999). The Middle Weichselian ice-sheet advance, which occurred around 65 ka BP, was of intermediate extent and reached only some 100 km inland from the present coast (Fig. 1B).
PARAGRAPH_XXO During both these events, the ice sheets dammed large proglacial lakes, filling the lake- and river basins both north and south of the Byrranga Mountains and, during the final stages of the different deglaciations, also lowland areas along the present coast. The water from north of the mountains drained southwards along the Taymyr River valley (where today the water flows northwards) into the Taymyr Lake basin and thereafter in most cases probably westwards to the Kara Sea shelf.
PARAGRAPH_XXO The last and least extensive glaciation – contemporaneous with the Last Global Glacial Maximum (LGM) – was short (<8000 years), culminated between 18 and 16 ka BP and was largely gone from present land by 12 ka BP. The thin ice (<500 m) seems to have been topographically controlled and limited to low-lying coastal areas and large river valleys. Nonetheless, it reached up to 100 km inland (Fig. 1B). No proglacial lake was formed at this time, but the subaerial proglacial drainage was reversed to the south, which caused a change in the sedimentation rate in the Taymyr Lake basin. 
PARAGRAPH_XXO We have studied the North Taymyr ice-marginal zone (NTZ; Fig. 1B), the northernmost of the major ice-marginal features on the Taymyr Peninsula, in some more detail since it seems to contain traces of all three Weichselian glacial events. It comprises ice-marginal and supraglacial landsystems dominated by 2-3 km wide block-thrust moraines and large-scale deformation of sediments and ice. Large areas are still underlain by remnant glacier ice and a supraglacial landscape with numerous ice-walled lakes and kames is forming even today. The proglacial landsystem is either subaqueous (e.g. deltas) or terrestrial (e.g. sandur plains), depending on location/altitude and time of formation. The nature of the NTZ in association with subglacial sediments found there and near Cape Chelyuskin suggest that the ice sheets, which covered the area, had a margin frozen to the bed and an interior moving over a deforming bed.
PARAGRAPH_XXO Results of dating (OSL, 14C) indicate that the NTZ was first initiated c. 80 ka BP during the retreat of the Early Weichselian ice sheet and that it also records the maximum limit of a Middle Weichselian glaciation (c. 65 ka BP). Part of the NTZ was also reached by the Late Weichselian (LGM) ice sheet.
PARAGRAPH_XXO This study has been done within the European Science Foundation’s QUEEN (Quaternary Environment of the Eurasian North) programme and its European Union-financed, mainly terrestrial sub-programme, ‘Eurasian Ice Sheets’. The combined results of the different groups working along the Eurasian arctic coast and in the adjacent seas suggest a Weichselian glacial maximum in northern Eurasia during the Early Weichselian and a considerably smaller ice sheet during the Late Weichselian (the last global glacial maximum), cf. the QUEEN volume of Global and Planetary Change (2001; vol. 31). These results falsify the concept of Grosswald and co-workers, who propose a large pan-Eurasian ice sheet during the Late Weichselian (e.g. Grosswald & Hughes 2002).

REFERENCE_XXO Grosswald, M.G., Hughes, T.J., 2002, The Russian component of an Arctic Ice Sheet during the Last Glacial Maximum: Quaternary Science Reviews, v. 21, p. 121-146.
REFERENCE_XXO MÑller, P., Bolshiyanov, D.Yu., Bergsten, H., 1999, Weichselian geology and palaeoenvironmental history of the central Taymyr Peninsula, Siberia, indicating no glaciation during the last global glacial maximum: Boreas, v. 28, p. 92-114.
REFERENCE_XXO Pavlidis, Yu.A., Dunayev, N.N., Shcherbakov, F.A., 1997, The Late Pleistocene of the arctic Eurasian shelves: Quaternary International, v. 41/42, p. 3-9.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/4-1.gif

CAPTION_XXO Fig 1.  A. Map of northern Eurasia showing the location of the Taymyr Peninsula. B. The Taymyr Peninsula with mentioned geographical names and major ice-marginal zones (hatched = uncertain). EW - Early Weichselian, MW - Middle Weichselian, LW - Late Weichselian, NTZ - North Taymyr ice-marginal zone.

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE FIRST EXPERIENCE OF SALINE DRAINAGE WATERS DISPOSAL FROM THE UDACHNAYA PIPE QUARRY INTO PERMAFROST

AUTHORS_XXO ALEXEEV, SERGEY V. (1); Drozdov, Alexander V. (2); Drozdova, Tatyana I. (3); Alexeeva, Ludmila P. (4)

AUTHOR_1_XXO (1) Institute of the Earth's Crust SB RAS, 664033, Irkutsk, Russia; salex@crust.irk.ru
AUTHOR_2_XXO (2) Udachny GOK JSC "ALROSA", 678189, Udachny, Russia
AUTHOR_3_XXO (3) Udachny GOK JSC "ALROSA", 678189, Udachny, Russia; Shmarov_G@ugok.alrosa-mir.ru
AUTHOR_4_XXO (4) Institute of the Earth's Crust SB RAS, 664033, Irkutsk, Russia; lalex@crust.irk.ru

PARAGRAPH_1_XXO The Udachnaya kimberlite pipe is one of the main diamond suppliers in Russia. It's situated on the Siberian platform in the central part of the Yakutian diamond province (Fig. 1). At present the exploitation of kimberlite deposit of the Udachnaya pipe is complicated by the influx of chloride magnesium-calcium subpermafrost brines into the quarry. The influx is 75-85 m3/hour. The ground water mineralization reaches 350 g/L, bromine and chlorine contents are hundred and thousand times the acceptable limiting concentrations. Therefore discharge of drainage waters into the river network is prohibited. 
PARAGRAPH_XXO For the last 15 years the open water drainage from the Udachnaya pipe quarry has been used. Brines are disposed into the Cambrian frozen rocks at the depths, which are lower than the local base level of erosion 150-250 m. The acting Octyabrskiy disposal polygon is situated on the watershed 3.5 km to the west from the quarry in the regional fault zone. The frozen strata here are broken into blocks, which is a result of step-like displacement of rock layers.
PARAGRAPH_XXO The method of waste isolation is grounded in the ability of high-mineralized water to melt structure-forming ice at wide range of negative temperature (Pinneker et al., 1989). The live capacity of the permafrost massif, used for drainage brines disposal, is dependent on a) 9% release of additional space at ice melting caused by brines in fractures and caverns, b) presence of the thick tectonic crush zone, along with open vertical and subvertical joints 10-15 cm wide and ice-free cavernous and porous rock with potentially high filtration properties, c) presence of large quantity (up to 5% from volume) of gas includes in the ground ice. The thickness of permeable rock strata and blocks varies from 10-20 cm up to 10-20 m (Alexeev, 2000).
PARAGRAPH_XXO Drainage system of the kimberlite deposit works the following way: drainage waters from the artificial reservoirs situated in different horizons are dumped into the inverted wells in the Oktyabrskiy polygon. Wastewater disposal into the wells is done by free filling without pressure on the well mouth. In summer brine temperature is +5...+8, in winter it decreases down to -15...-25 (C. At the disposal into permafrost the descending and lateral migration of technogenic water takes place. Firstly brines move along vertical and subvertical joints down to the lower part of strata. Then plane filtration along the interlayer joints occurs. Injection of the indicator (fluorescein) into the inverted wells demonstrates that the hydraulic conductivity coefficient of technogenic waters in the massif reaches 1-1.5 m/day. 
PARAGRAPH_XXO During the period 1985-2001 over 10.000,000 m3 of brines were buried into the permafrost of Oktyabrskiy polygon. Some part of technogenic solutions returns to the quarry, which is proved by numerous icings observed in the quarry slopes (Fig. 2). Closed talik has formed inside the frozen massif.  Technogenic waters are spread within the distance of 6-8 km. A recent hydrogeological survey concluded that the massif capacity in the Octyabrskiy polygon would allow containing about 2.000,000 more m3 of brines in the nearest future. There has been also a change in thermal condition of the rock massif: before the disposal system was exploited the rock temperature at the depth of 200 m was -2 (C. After a 5-year brine disposal it decreased down to -5 (C. The most cooled layers are at the depth of 160-240 m accordingly to the technogenic aquifer. Deposit exploitation in spring and in summer is rather complicated by atmospheric precipitation inflowing to the quarry. Its volume reaches up to 300,000-400,000 m3 during the period of June - the end of August. Additional reservoirs on the berms were created to intercept surface water. Accumulating waters have sulfate-chlorine magnesium-calcium composition. Their mineralization is 10-30 g/L and bromine content is 0.2-0.3 g/L. of Such technogenic solutions are discharged into the river network only if previously significantly diluted, which requires not less than 300-400.000.000 m3 of fresh water, but there is no such amount in the immediate vicinity.  
PARAGRAPH_XXO In this relation the necessity arose to search reliable storages for large volumes of salty drainage waters, inflowing in the quarry in spring and summer. The acting Oktyabrskiy polygon seemed the most ecologically safe and technico-economical profitable. A technological scheme of salty water disposal in the Oktyabrskiy polygon in summer was worked out. Both freezing temperature of different mineralized technogenic solutions and thermal condition of permafrost were taken into account. The essence of the method is alternating discharge of salty surface water and drainage brines into inverted wells. At the first stage salty waters are discharged. Coming in the massif, they are mixed with cryopegs within closed talik and supply resources of the technogenic aquifer. Meanwhile wastewater mineralization decreases and wastewater further freezes. Salty waters are discharged into the disposal polygon until intensity of their absorption is fixed. At the second stage brines are discharged. Brines with positive temperature and high mineralization gradually melt newly formed ice in reservoirs and move deep into the massif. When brine absorption intensity becomes stable, discharge stops and salty water discharge is renewed. And so on.
PARAGRAPH_XXO To estimate the scale of geochemical processes at mixing of different types of technogenic waters, the physico-chemical simulation was carried out. The simulation was conducted using software HydrGeo designed at the Tomsk Department of the Institute of Petroleum and Gas Geology SB RAS (Bukaty, 1997). The average results of the analyses of drainage brines and salty surface water are used as initial data. The simulation and estimation of solution composition change were made at the mixing of technogenic water under the real PT conditions (T= -5, 0, +5 oÑ and Ð=2.5 ÌPà). Calculations were made for the proportions of solution in the mixture from 90:10 to 10:90 %. It's been established that all obtained mixtures have different levels of saturation of the calcite, dolomite and gypsum; moreover the unsaturation degree increases with growth of mixed water mineralization, i.e. with the growth of the drainage water amount in the mixture. Under the layer conditions the dilution of interactive solutions will only occur without modification of water chemical composition. Therefore there are no causes for precipitation and filtration properties decrease of the rock massif.
PARAGRAPH_XXO In summer 1997 an experimental discharge of technogenic salty water and brines into the inverted wells was carried out. The intensity of brine absorption in each well was not less than 100 m3/hour. The alternating waste disposal was carried out 16-50 hours without pressure on the well mouth. Ultimately during the natural experiment 59 000 m3 of salty water and 73 280 m3 of drainage brines were discharged into the massif on the Oktyabrskiy polygon.
PARAGRAPH_XXO The obtained results confirm groundness of technological scheme of salty drainage water disposal in the Oktyabrskiy polygon. Realization of the elaborated method will provide long non-stoppage work of the Udachnaya diamond mining quarry.
PARAGRAPH_XXO The study has been carried out with the financial support of Russian Fund for Basic Research (grant's number 01-05-64012).

REFERENCE_XXO Alexeev, S.V., 2000. The cryogenesis of groundwaters and rocks (on an example of the Daldyn-Alakit region of Western Yakutia). SPC UIGGM, Novosibirsk (in Russian).
REFERENCE_XXO Bukaty, M.B., 1997. "The working out of the software in the petroleum-gas geology." J. Razvedka i ohrana nedr. N 2, 37-39 (in Russian).
REFERENCE_XXO Pinneker, E.V., Alexeev, S.V., and Borisov, V.N., 1989. The interaction of brines and permafrost. In WRI-6 International Symposium, 1989, Proceedings: Rotterdam, Balkema, pp. 557-560.      

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/10-1.jpg

CAPTION_XXO Fig 1.  Position of the Udachnaya kimberlite pipe

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/10-2.jpg

CAPTION_XXO Fig 2.  Icings of salty technogenic waters in the Udachnayalale pipe quarry<br><br>

INSERT_PAGE_BREAK_HERE
TITLE_XXO LESSONS FROM THE BENCH GLACIER, CHUGACH RANGE, ALASKA: SLIDING SPEEDS AND EROSIONAL OUTPUT REFLECT SEASONAL EVOLUTION OF THE SUBGLACIAL HYDROLOGIC SYSTEM

AUTHORS_XXO ANDERSON, ROBERT  S. (1); MacGregor, Kelly R. (2); Riihimaki, Catherine A. (3); Anderson, Suzanne  P. (4); Waddington, Ed D. (5)

AUTHOR_1_XXO (1) UC Santa Cruz; rsand@es.ucsc.edu
AUTHOR_2_XXO (2) UC Santa Cruz; kelly@es.ucsc.edu
AUTHOR_3_XXO (3) UC Santa Cruz; riihimak@es.ucsc.edu
AUTHOR_4_XXO (4) UC Santa Cruz; spa@es.ucsc.edu
AUTHOR_5_XXO (5) Univeristy of Washington; edw@geophysics.uw.edu

PARAGRAPH_1_XXO Basal sliding paces erosion by both abrasion and quarrying.  Any model of glacial modification of a landscape must therefore include at a minimum the temporal and spatial pattern of sliding.  As part of a project designed to explore the long term evolution of alpine valley longitudinal profiles in the face of glacial cycles, we have studied the 7 by 1 km, 180 m thick Bench Glacier near Valdez in the Chugach Range of Alaska, for two melt seasons.  One of our principal targets was the pattern of sliding velocity over the length of the glacier and its change through the summer melt season.  We have documented the glacier shape, the meteorological forcing of the glacier, the hydrological balance, the surface velocity field, and the erosional output of both sediment and solutes.  
PARAGRAPH_XXO Glacial thickness.  The Bench Glacier was chosen for its simple geometry (it has no tributaries), its moderate size, and its accessibility.  Fourteen cross-glacier radar profiles revealed a thickness profile with a maximum thickness of 180 m, and relatively symmetrical U-shaped cross sections.  Present day basal shear stress in the ablation zone averages roughly 70000 Pa when adjusted appropriately with a shape factor that reflects the valley cross section.
PARAGRAPH_XXO Meteorolology.  We established each summer a met station in the upper ablation zone measuring air temperature, incoming radiation, wind speed, precipitation and snow thickness at 15-minute intervals.  In addition, we deployed shielded Hobo data loggers to record air temperature at the same intervals at 8 ablation stakes on the glacier.  Summer rain and snow were minimal in these two years.  The spatial pattern of mean air temperatures was essentially uniform along the glacier centerline, showing no simple lapse rate over the 600 m elevation gain from terminus to headwall.  On-glacier temperatures were very different from those measured on the glacier foreland and on the adjoining ridge.  Wind was consistently down-glacier, and was well established by mid-day.  This katabatic wind presumably homogenizes the air temperatures.  Snow thickness changes at rates dictated by both the daily and longer period storm cycles.
PARAGRAPH_XXO Balance.  As the glacier has receded by several km from its Little Ice Age moraines, it has been in long term negative balance.  Retreat rates have averaged 25 m/year since 1950.  Snow probing upon arrival revealed the accumulation pattern.  In both years the snow thickness increased two-fold from terminus to headwall, but was much thicker in 2000 than in 1999.  Snowpits in the early melt season documented uniform profiles of snow densities of 480-520 kg/m^3, allowing conversion of snow thickness changes to melt water equivalent.  Frequent measurement of snow depths at 12 to 14 ablation stakes along the centerline of the glacier revealed the pattern of snow melt through the melt seasons.  Melt rates consistently increased toward the terminus despite the essentially uniform air temperatures and the expected uniformity of the incoming radiation.  This implies that the evolution of the albedo field plays a central role in establishing the pattern of melt generation.  As the snow is thinner on the terminus, low albedo ice crops out earlier on the terminus than higher on the glacier, promoting higher melt toward the terminus.  The pattern of specific balance derived from combining accumulation and melt patterns is close to linear with elevation.  High accumulation in 2000 translated into a positive net balance of roughly one million cubic m, while 1999 was highly negative; at –6 million cubic m, it was typical of the last 50 years.  Measurement of both meltwater inputs and water outputs at the exit stream revealed a picture of glacial storage through the melt season.  Each summer, this storage peaks in the early melt season, maximum storage corresponding to tens of cm of water thickness. 
PARAGRAPH_XXO Glacial response over the melt season.  We employed both optical and GPS methods to document the spatial pattern of surface motion throughout both melt seasons.  Both summers yielded similar surface speed evolution.  A steady background surface speed field of roughly 2-3 cm/day is interrupted only once per year by an up-glacier propagating wave of elevated velocities.  This anomaly initiates at the terminus, propagates at a speed of 250 m/day, and involves roughly 1-km of the glacier at a time.  Surface speeds reach up to an order of magnitude above background, reaching 30 cm/day; peak speeds increase up-glacier.  A high resolution time series or speeds from GPS-derived 4-hour positions at a stake in the upper ablation zone reveals that the arrival of the horizontal speed anomaly at a site is associated with a vertical speed anomaly, indicating divergence of the motion from bed-parallel.  Maximum divergence suggests bed separation of order 15 cm.  Bed-parallel motion is re-achieved within 4 days after the abrupt slowing of the horizontal speed back to background values.  We interpret this speed anomaly to reflect sliding at the glacier bed.  The period over which the sliding wave propagates upglacier corresponds to the time of high storage of water within the glacier.  We interpret the background speeds, both late summer averages and winter averages, as being related to internal deformation of the ice.  Using the pattern of surface speed, ice thickness and surface slope, we conclude that the rheology of the relatively thin ice in the ablation zone is dominated by a linear (n=1) relation between stress and strain rate, with an ice viscosity of roughly 2 x1013 Pa-s.  This corroborates recent results form a large scale experiment on the nearby Worthington Glacier, in which the rheology changes from n=1 to n=3 at a critical stress.  Given the surface slopes in the ablation zone of the Bench Glacier, this corresponds to roughly 120 m depths.
PARAGRAPH_XXO Erosional output.  Sediment.  We have monitored both the water and sediment discharge from the glacier at a gage site only 500 m from the terminus.  We have converted the 15- minute time series of turbidity to surface (suspended) sediment concentrations using a rating curve derived from simultaneously collected surface water samples.  In 1999 we also attempted to document bedload transport using an acoustic method, taping one minute of hydrophone noise per hour.  This was calibrated with measurements of bedload in which the entire flow of the stream was sent through a coarse mesh fence.  In 2000 we performed bedload measurements using a Helley-Smith sampler.  The relationship between sediment discharge and water discharge shows significant hysteresis.  No simple rating curve can be established.  The bedload in particular appears to become depleted over the summer.  The proportion of bedload is many tens of percent of the total sediment yield.  We interpret the hysteresis to reflect the exhaustion of the sediment source at the glacier bed.  In the case of bedload, this implies that sediment has been effectively removed from an area of the bed corresponding to the footprint of the subglacial channel system.  Integration of the sediment discharge through the melt season suggests a mean subglacial sediment evacuation rate of roughly 1 mm/yr.  
PARAGRAPH_XXO Solutes.  We also monitored the chemistry of the outlet waters.  Samples were collected twice daily, allowing calibration of a 15-minute time series of conductivity.  The conductivity (hence TDS) showed considerable variation over the melt season, with several periods of distinct behavior.  Swings in TDS indicate mixing between a consistent low concentration end-member and an evolving high concentration end-member.  This high end-member becomes progressively more dilute over the summer, suggesting that subglacial residence times decline.  Breaks in the behavior correspond in many instances with major step changes in water discharges.  
PARAGRAPH_XXO We are currently attempting to synthesize this information into a model of glacial motion and erosion over an annual cycle.  The sliding pulse, the sediment discharge, and solutes reflect the evolution of the subglacial drainage system.  We envision the following seasonal cycle.  If sliding is inversely proportional to the effective pressure at the bed, the sliding pulse becomes a probe of the evolution of the subglacial pressure field.  The pressure field increases as melt is released from the snowpack and makes its way toward the bed.  In the early melt season, melt water inputs exceed outputs, reflecting the inefficiency of the subglacial drainage system; the channel system and the connections between cavities have collapsed over the winter.  Sliding initiates at the terminus where melt is most prolific.  Sliding terminates when the pressures decline, due to either 1) the generation of subglacial storage space by the opening of cavities by sliding, or 2) the establishment of more efficient drainage due to connections between cavities or upglacier insertion of a channel system.  This sliding termination propagates upglacier as the water must be drained toward the low pressure point maintained at the exit.  Water with long contact times with subglacial sediment, and the sediment itself, is exhausted from the subglacial system through the melt season, yielding strong hysteresis in the sediment – water discharge relationship, and strong seasonal trends in the high end-member solute concentrations.
PARAGRAPH_XXO In summary, this small alpine glacier achieves all of its annual sliding in a short pulse in the early melt season, the upglacier propagation of which must reflect the evolution of the subglacial drainage system.  Even this small glacier is capable of eroding its bed at a high rate of about 1 mm/yr.  The simultaneous collection of meteorological, glaciological, and sediment discharge data provides strong constraint on all the components of the system that are relevant to the construction of models of the generation of the long term glacial signature in alpine valleys.

INSERT_PAGE_BREAK_HERE
TITLE_XXO LAKE RESPONSE TO METEOROLOGICAL FORCING ALONG A CLIMATE GRADIENT IN THE LOW ARCTIC OF WEST GREENLAND.

AUTHORS_XXO ANDERSON, JOHN (1); Brodersen, Klaus P. (2)

AUTHOR_1_XXO (1) Geological Survey of Denmark & Greenland; njanderson@smm.org
AUTHOR_2_XXO (2) Freshwater Biological Lab.,  University of Copenhagen; kpbrodersen@zi.ku.dk

PARAGRAPH_1_XXO Lakes respond to climate forcing at a variety of timescales.  Long-term (i.e. Holocene) changes in lake response to climatic variability can be modeled by understanding contemporary response, such as high-frequency breakdowns in thermal stratification driven by cooling and increased wind speed. However, direct meteorological forcing is tempered by lake size and morphometric setting. West Greenland contains thousands of lakes along a climatic gradient of low effective precipitation and continentality at the ice sheet margin to the more maritime (cooler and wetter) conditions at the coast (~150 km). 
PARAGRAPH_XXO We used temperature thermistors in 40 lakes and two automated weather stations to monitor changing thermal response (including date of ice melt) to climatic variability since 1998. Thermistors were placed in the littoral zone of lakes immediately prior to ice melt in 1998 and 1999. In 1999 we also placed strings of thermistors (4-8 per lake) in the deepest part of the basin so we could monitor the development of thermal stratification. From May 2000, however, the thermistors have been recording continuously at a number of sites. To confirm the date of ice melt as recorded by the thermistors we have also used remote control digital cameras which take one photograph everyday, thereby recording the rate of ice melt.
PARAGRAPH_XXO The response of individual lakes to a meteorological event is related to their size, catchment characteristics and chemistry.  The range in date of ice melt reflects interannual differences in air temperature and lake location. There is, however, considerable synchroneity in the timing of lake stratification response to changing weather patterns. The implications of these results for interpreting high-resolution stratigraphic records are discussed.

INSERT_PAGE_BREAK_HERE
TITLE_XXO KENNICOTT GLACIER OUTBURST FLOODS:  REAL TIME OBSERVATIONS AND SUBGLACIAL HYDROLOGIC MODELING

AUTHORS_XXO ANDERSON, SUZANNE P. (1); Walder, Joseph S. (2); Anderson, Robert S. (3); Kraal, Erin R. (4); Fountain, Andrew G. (5); Cunico, Michele (6); Trabant, Dennis (7)

AUTHOR_1_XXO (1) University of California, Santa Cruz; spa@es.ucsc.edu
AUTHOR_2_XXO (2) U.S. Geological Survey; jswalder@usgs.gov
AUTHOR_3_XXO (3) University of California, Santa Cruz; rsand@es.ucsc.edu
AUTHOR_4_XXO (4) University of California, Santa Cruz; ekraal@es.ucsc.edu
AUTHOR_5_XXO (5) Portland State University; bjaf@pdx.edu
AUTHOR_6_XXO (6) Portland State University; mcunico@hotmail.com
AUTHOR_7_XXO (7) U.S. Geological Survey; dtrabant@usgs.gov

PARAGRAPH_1_XXO Glacial outburst floods, which occur when bodies of water impounded by glaciers drain suddenly, produce catastrophic floods that can reshape river channels and pose a significant hazard downstream.  Our understanding of the triggers for these floods is severely hampered by inaccessibility and relatively unpredictable timing.  We have taken advantage of an ice-dammed lake that has produced annual outburst floods for the last 100 years at the Kennicott Glacier in south-central Alaska to monitor outburst floods in two consecutive years.  
PARAGRAPH_XXO Hidden Creek Lake (HCL) forms each summer in a deglaciated tributary to the Kennicott Glacier, located in the Wrangell Mountains of south-central Alaska (Figure 1).  Outburst floods from Hidden Creek Lake have been observed for nearly a century (Rickman and Rosenkrans, 1997).  The date of the annual outburst has become progressively earlier in summer over this time, but there is considerable interannual scatter.  This scatter does not reflect simple differences in the rate at which the lake reaches some critical level; the maximum lake level differed by 9 m between 1999 and 2000.  Assuming that peak discharges are related to lake volume (Clague and Mathews, 1973), differences in peak flood stage measured in the Kennicott River over a number of years also suggest that the lake drains at different levels each year.
PARAGRAPH_XXO Our observations during the melt seasons of 1999 and 2000 included lake level history, lake basin hypsometry, ice dam deformation, water pressure in boreholes in the ice dam, and discharge, suspended sediment concentrations and water chemistry in the Kennicott River.  In 2000, we also monitored flow in Hidden Creek (the major input into Hidden Creek Lake), and the filling and drainage history of Donoho Falls Lake, an ice-marginal basin down glacier from Hidden Creek Lake.  Our stream gauging of the Kennicott River is augmented by daily stage measurements in the summer over the last five years, and we have acquired daily meteorological observations at cooperative station at McCarthy from the National Weather Service.  
PARAGRAPH_XXO In 1999 and 2000, the HCL outburst occurred at the termination of a period of high discharge in the Kennicott River, and was followed within a few days by a period of very low discharge.  Examination of Kennicott River stage records from 1997-2001 show that this pattern is typical.  Long-period (10-20 day) oscillations of the river stage are evident in most summers.  In 1999 and 2000, the same oscillations are also observed in our measurements of the electrical conductivity (EC) in the river, but the EC variations lag stage variations by several days.  We infer that the discharge and chemistry both reflect variations in meltwater inputs, but with a lag imposed by the time required to expand or close subglacial conduits in response to these changing inputs (Anderson et al., submitted).  As a result, the amount of water stored in the glacier oscillates throughout the melt season.  
PARAGRAPH_XXO Lake drainage in 2000 was complete in 2.5 days.  Drainage in 1999 appears to have followed the same pattern, although since lake drainage was underway at the beginning of our observations we cannot be certain about the onset.  In both years, Kennicott River discharge began to rise 1-1.5 days after HCL drainage began.  In 2000, our observations in Donoho Falls Lake show that this previously emptied basin began to fill at about the same time that the Kennicott River began to rise.  Peak suspended sediment concentrations in the Kennicott River in both years occurred about 12 hours before peak water discharge.  Donoho Falls Lake rapidly reached a steady high level in 2000, and drained equally rapidly a few hours after the peak flow in the Kennicott River.  The flood hydrographs in both years were more symmetrical than is generally associated with glacial outburst floods (Tweed and Russell, 1999).  The integrated flood discharge was within error equivalent to the volume of the lake in each year.  
PARAGRAPH_XXO Passage of the flood wave through the glacier disrupts "normal" subglacial drainage.  The chemistry of the water that filled Donoho Falls Lake basin differed from HCL water, indicating that Donoho Falls Lake filled with subglacial water, perhaps from the Root Glacier (Fig. 1), that is temporarily backed-up during the passage of the flood wave.  This interruption to subglacial flow occurred only after the discharge in the Kennicott River began to exceed the maximum it had reached earlier in the summer.  That Donoho Falls Lake maintained a steady high level for about a day suggests that subglacial conduits grew at a rate sufficient to accommodate both increasing discharge from HCL and background melt water from the remainder of the glacier.  After HCL drainage was completed, the conduit system, at least from the terminus up to vicinity of the lake, is presumably larger than is necessary for transmission of melt water production.  This promotes drainage from the distributed flow system.  Discharge from the glacier falls to a summer low at this time.
PARAGRAPH_XXO We have constructed a lumped-element model of the subglacial hydrologic system (Clarke, 1996).  The quasi-two dimensional model allows for flow between a series of nodes using equations that represent expansion and contraction of Rothlisberger conduits.  Lateral flow into the nodes is also allowed using physics that mimic flow within the linked-cavity distributed flow system.  We initiate the model with small (cm scale) conduits; mass balance on melt inputs and flow out of each node, combined with an assumed glacier porosity, determine the head at each node.  Conduits grow up from the terminus in our model runs; once established, the conduits provide a low-head gradient fast flow system, fed by the high-head distributed flow system.  The entire system responds to variations in melt water inputs.  
PARAGRAPH_XXO A key hypothesis is that hydrologic head within the basal drainage system near the lake may control drainage of the ice-dammed lake.  We hypothesize that catastrophic drainage occurs when the head gradient between the lake and subglacial drainage system near the lake is sufficient to open a Rothlisberger conduit, and that this condition is met only when head in the distributed flow system near the lake falls below the head in the lake.  We are beginning to explore these hypotheses with the lumped-element model of subglacial hydrology.  

REFERENCE_XXO Anderson, S.P., Longacre, S.A., and Kraal, E.R. (submitted):  Patterns of water chemistry and discharge in the glacier-fed Kennicott River, Alaska:  Evidence for subglacial water storage cycles, Chemical Geology.  
REFERENCE_XXO Clague, J.J., and Mathews, W.H. (1973):  The magnitude of jokulhlaups, Journal of Glaciology 12 (6):  501-504.
REFERENCE_XXO Clarke, G.K.C. (1996):  Lumped-element analysis of subglacial hydraulic circuits, Journal of Geophysical Research 101 (B8):  17,547-17,559.
REFERENCE_XXO Rickman, R.L. and Rosenkrans, D.S. (1997):  Hydrologic conditions and hazards in the Kennicott River basin, Wrangell-St. Elias National Park and Preserve, Alaska, U.S. Geological Survey Water-Resources Investigations Report 96-4296.
REFERENCE_XXO Tweed, F. S., and Russell, A.J. (1999):  Controls on the formation and sudden drainage of glacier-impounded lakes:  implications for jokulhlaup characteristics, Progress in Physical Geography 23 (1):  79-110.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/70-1.JPG

CAPTION_XXO Fig 1.  Map of ice-dammed Hidden Creek Lake and terminus region of the Kennicott Glacier.  Approximate maximum lake areas in 1959 and in 2000 shown.  Elevations in feet.

INSERT_PAGE_BREAK_HERE
TITLE_XXO EVIDENCE FOR EARLY HOLOCENE ATLANTIC WATER ON THE NORTH AMERICAN ARCTIC SLOPE AND AN EARLIEST HOLOCENE MELTWATER EVENT

AUTHORS_XXO ANDREWS, JOHN T. (1); Dunhill, Gita (2)

AUTHOR_1_XXO (1) INSTAAR and Department of Geological Sciences, Box 450; andrewsj@spot.colorado.edu
AUTHOR_2_XXO (2) INSTAAR and Department of Geological Sciences, Box 450; Gita.Dunhill@colorasdo.edu

PARAGRAPH_1_XXO Core P189AR-P45 (henceforth P45) was collected in 405 m of water at 70° 33.03?N and 141° 52.08?W   on the slope of the Beaufort Sea and west of the Mackenzie River delta.  The 511 cm core has a basal (uncorrected) radiocarbon date of 11,240 ± 140 BP and the date on the core top is 7920 ± 110.  Four other dates define a linear rate of sediment accumulation of around 135 cm/ky.  An ocean reservoir correction of ~800 yrs is applied to the dates, based on the measurements of molluscs collected prior to the ?bomb effect?.  The coring site is located at a depth dominated by modified Atlantic Water.  This relatively warm water mass lies below the cold and fresher coastal and shelf waters which maintain a heavy cover of sea-ice throughout much of the year.  An synthesis of hydrographic data from the Arctic Ocean (Steele et al.) indicated that at the core site the water temperature is about 0.4°C with a salinity of 34.8?.  We have measured a variety of sediment properties including grain-size, TOC and Carbonate weight %.  We have undertaken stable isotopic measurements (d18O and d13C) on both planktonic foraminifera (N. pachyderma s) and the benthic species Cassidulina neoteretis and determined species composition at a coarser sampling resolution.  A key observation is that in the early part of the record, in the earliest part of the Holocene, that the fauna is dominated by Cassidulina neoteretis, a benthic species which is used as an indicator of modified Atlantic Water.  This species becomes less important after about xx ka and is replaced by elements more common in Arctic assemblages, such as Cassidulina reniforme.  Despite the presence of large tidewater ice sheet margins in the Canadian Arctic Channels > 10 ka (cf. Dyke and Savelle, 2000) there is little specific evidence for pervasive iceberg rafted detritus (IRD) and indeed the sediment is finer at the base of the core.  The d18O records for both benthic and planktonic foraminifera exhibit significant variability but both records also posses a statistically significant trend toward higher d18O values back in time.  The highest d18O values in both data sets occurs around 9.5 ka.    A notable feature of both records is a light d18O peak which occurs around 10 ka; in the benthic data the ?d18O between that peak and troughs on either side is > 1?.   We believe that this ?meltwater spike? might be evidence for the large outburst flood down the Mackenzie River drainage noted by Fisher et al (2002).  The ?d18O between benthic - planktonic d18O indicates that this difference has increased toward 6.8 ka
PARAGRAPH_XXO References
PARAGRAPH_XXO Dyke, A. S. and Savelle, J. M., 2000: Major end moraines of Younger Dryas age on the Wollaston Peninsula, Victoria Island, Canadian Arctic: implications for paleoclimate and for formation of hummocky moraine. Canadian Journal of Earth Sciences, 37: 601-619.
PARAGRAPH_XXO Fisher, T. G., Smith, D. G., and Andrews, J. T., 2002: Preboreal oscillation: North Atlantic cooling caused indirectly by a glacial Lake Agassiz flood, 13,000 years ago. Quaternary Science Reviews.
PARAGRAPH_XXO Steele, M., Morley, R., and Ermold, W., 2001: A Global Ocean hydrography with a high quality Arctic Ocean. Journal of Climatology, 14: 2079-2087.

INSERT_PAGE_BREAK_HERE
TITLE_XXO ENVIRONMENTAL HISTORY OF THE NOVOSIBIRSKIE ISLANDS FOR THE LAST 12 KA

AUTHORS_XXO ANISIMOV, MIKHAIL A. (1); Tumskoy, Vladimir E. (2)

AUTHOR_1_XXO (1) Arctic and Antarctic Research Institute; verkulich@aari.nw.ru
AUTHOR_2_XXO (2) Moscow State University, Faculty of Geology; tumskoy@orc.ru

PARAGRAPH_1_XXO The presented materials generalize paleo-geographical studies of Kotelnyi and Zhokhov Islands (Makeev et al., 1989, 1999), Bennetta Island (Verkulich et al., 1989,1999) and fieldwork of different years performed by the authors on Bennetta, Zhokhov, Bol. Lyakhovskii and Novaya Sibir Islands.
PARAGRAPH_XXO The New Siberian islands are located on the continental shelf presenting fragments of an extensive plain that existed during the period of the last (Sartanian) cooling. The sea level at that time was 100-120 m as low as the modern one, which determined the coastline location of 700-1000 km to the north compared to the current one. 
PARAGRAPH_XXO No thick ice sheet glaciers similar to Scandinavia or North America existed in the region of the New Siberian Islands. Numerous 14C datings in range 24-17 ka confirm its. Small passive ice sheets were only on the northern islands of the archipelago. Their fragments are still preserved on Bennetta, Genrietta and Zhannetta Islands. Unclear traces of the car-near-slope glaciers in the form of unpronounced ice deposits are preserved on Zhokhov Island. Over much of the territory, deposits of different genetic types with high ice content accumulated, whose typical feature was the presence of big ice wedges (Ice-Complex deposits). The thickness of deposits increased southward from 5-10 m to 50-70 m.
PARAGRAPH_XXO As a result of a series of warming events in the end of the Late Pleistocene and the decay of ice sheet glaciers in the north of Europe and America, the sea level rise began in the eastern Arctic with the coastline advancing southward. According to the results of studies in the Laptev Sea region (Degtyarenko et al., 1982; Bauch et al., 2001), the sea level rise began around 17 kyr BP achieving its current position around 5 kyr BP. The coastline was, however, located much more to the north than at present.  Thus, rocks with high ice content were not yet destroyed by thermal abrasion. The marine transgression reached its maximum around 4 kyr BP. The sea level at this time was 3-4 m higher than the current one whereas the coastline was in tens and hundreds of kilometers from its present position. Due to the fact that the overwhelming parts of shores was comprised of deposits with high ice contents, the terrace levels formed at this time were destroyed due to thermal abrasion and were preserved only on some segments of bedrock outcrops. For examples, there are radiocarbon datings of driftwood from a laida (with a height of 4-5 m) in the northern part of Zhokhov Island (4.9-3.9 kyr BP). Insignificant climate coolings in the Holocene resulted in slower rates of sea transgression or in some regressions. Due to this, probably around 9 kyr BP, a terrace level at a depth of about 15 m (Zhokhov Island) was formed. The presence of a large quantity of the driftwood fragments at the monument (Zhokhov Island) and the features of depth distribution around Zhokhov Island provide indirect evidence of this. We have recorded one more insignificant sea level rise on Stolbovoy Island. A band of driftwood concentration was dated at a distance of 60-70 m from the shore at a height of about 3 m above the sea level. The radiocarbon age of wood is 1255±40 kyr BP (LE-5850). There was a short-term warming at this time and it is also probable that the driftwood band was formed due to strong storms in the ice-free sea.
PARAGRAPH_XXO During the warming periods of the end of the Late Pleistocene (Raunis, Bolling and Allerod climatic stages) the area of the New Siberian Islands still presented one continental land, which is indicated by dating of the mammoth tusk from Bennetta Island (12.5 kyr BP). 
PARAGRAPH_XXO The decrease of climate continentality and increased humidity in the end of the Late Pleistocene resulted in a sharp intensification of thermokarst processes. The accumulation of deposits with high ice content on land was replaced by their melting. On Novaya Sibir Island, a horizontally bedding organic interlayer with an age of 11050±60 (GIN-11246à) overlaps a cast along the ice wedges. On Novaya Sibir Island, there is also a date of 10750±100 years BP (GIN-11247à) obtained from an interlayer of allchthonous peat filling a thermokarst basin. Intensification of solifluction and thermal erosion belongs approximately to this time. There are similar datings from Bol. Lyakhovskii Island.
PARAGRAPH_XXO  The formation of peat bogs began synchronously in series with the development of thermokarst depressions. On Kotelnyi Island, they are dated beginning from 12.3 kyr BP (LU-1763) and on Zhokhov Island from 12.2 kyr BP. Milder temperature conditions resulted in the vegetation boundary advance northward. In peat bogs on Zhokhov, Kotelnyi, Novaya Sibir and Bol. Lyahkovskii Islands, numerous remnants of shrubs growing here in the Holocene were encountered. A decrease in intensity of the mass thermokarst development belongs to the middle of the Holocene. Around 3 kyr BP, the accumulation of peat bogs ends (3380±40, LE-5854 - peat bog on Novaya Sibir Island).
PARAGRAPH_XXO Visit of Zhokhov Island by man belongs to the Holocene optimum (around 8 kyr BP). Due to bathymetry features near Zhokhov Island, the distance from the site of ancient people to the seashore was not greater than several kilometers. A large quantity of driftwood remains and bone remnants of a sea animal at the ancient man site serve as indirect evidence. 
PARAGRAPH_XXO The available data on the Novosibirskie Islands indicate synchronous climatic changes in the territory of the eastern Arctic shelf. These changes were of a complicated rhythmic character determined not only by temperature fluctuations, but also by climate changing from continental to marine due to sea transgression.

REFERENCE_XXO Makeev V.M., Pitulko V.V. and Kasparov A.K. (1999) De-Long Archipelago environment at the end of the Pleistocene and beginning of the Holocene and ancient human. - In: Proceedings RGO, vol. 124, N3, pp. 271-276 (in Russian)
REFERENCE_XXO Makeev V.M., Arslanov H.A., Baranovskaya O.F., Kosmodamianskii A.V., Ponomareva D.P., Tertychnaya T.V. (1989) Stratigraphy, geochronology and palaeogeography of Kotel`ny Island at the Late Pleistocene and Holocene. - In: Committee bulletin for the Quaternary time investigation, N58, pp. 58-69
REFERENCE_XXO Verkulich S.R., Makeev V.M., Arslanov H.A., Ponomareva D.P., Tertychnaya T.V., Baranovskaya O.F. (1989) Structure and geochronology of the Quaternary deposits on the Bennett Island. - In: Quaternary Geochronology. Abstracts, p.16. Tallin.
REFERENCE_XXO Verkulich S.R., Bolshiyanov D.Yu., Makeev V.M., Anisimov M.A. (1995) Investigations of the Arctic in the framework of paleogeographical studies of the AARI. - In: Second Annual PALE Research Meeting, 4-6 February 1995, University of Washington. Abstracts. Washington, p. 5

INSERT_PAGE_BREAK_HERE
TITLE_XXO AN INVESTIGATION OF LOCAL ALPINE TERRESTRIAL TEMPERATURE LAPSE RATES IN THE CANADIAN ROCKIES

AUTHORS_XXO ANSLOW, FARON S. (1); Shawn, Marshall J. (2)

AUTHOR_1_XXO (1) University of Calgary; fsanslow@ucalgary.ca
AUTHOR_2_XXO (2) University of Calgary; smarshal@ucalgary.ca

PARAGRAPH_1_XXO A common problem in alpine climatological and meteorological investigations is the lack of high spatial resolution meteorological records over the area of study. This need is demonstrated by studies ranging from Laurentide Ice Sheet modelling to alpine glacier energy balance models.  Frequently in North America the available data is that from national climate station networks (such as Environment Canada and National Weather Service) whose spacing is of the order of 50 km or more, and are often located in urban areas rather than the remote alpine environs under study. For paleoclimatological work the situation is even more dire as temperature data is only available from widely spaced Global Climate Model (GCM) output or from geological proxies.  For work where resolution greater than ca. 50 km is desired, temperature data must be extrapolated across the landscape using lapse rates.  
PARAGRAPH_XXO Such extrapolations require an understanding of the vertical temperature lapse rate for the region, and commonly a value in the range of 5.5 °C km -1 to 6.5 °C km –1 is applied and assumed constant for a multitude of landscapes and climate regions.  This range of values is derived from conditions measured in the free atmosphere where temperatures are much less affected by surface radiative transfer, frictional properties and diurnally evolving temperature structures.  On the surface, where the lapse rate is applied, these influences are important to the measured temperature.  One study done to account for this inconsistency determined lapse rates using surface temperature data taken from National Weather Service climate stations, however, this data was too wide spread to provide lapse rates for mountainous regions on the scale of individual valleys and ridges as are often needed. 
PARAGRAPH_XXO To help begin to fill this void we have made measurements of temperature along both glaciated and deglaciated alpine valleys in the Rocky Mountains, Canada. HOBO and Veriteq temperature data loggers were placed at 100m vertical intervals along three separate valleys including one transect that reached from valley mouth to glacier headwall.  Temperature was recorded at 10 minute intervals to capture short as well as long term fluctuations at each sampling site. Presented here are the lapse rates derived from the initial 3 months of this data.  We show that temperature depends strongly on underlying surface types and changes in local diurnal temperature structure.  Based on the data presented here, we feel that application of a uniform lapse rate across large areas is not appropriate.

INSERT_PAGE_BREAK_HERE
TITLE_XXO HIGH RESOLUTION JULY MEAN AIR TEMPERATURE DATA FOR THE CANADIAN ARCTIC ARCHIPELAGO, 1957-2001

AUTHORS_XXO ATKINSON, DAVID E.

AUTHOR_1_XXO University of Ottawa; atkinson@climate.geog.uottawa.ca

PARAGRAPH_1_XXO A new set of July mean air temperature data from a high-resolution topoclimatic model will soon be available for the Canadian Arctic Archipelago and the northern coast of North America. Data are available on a projected grid with a roughly 1 km x 1 km spatial resolution for the years 1957 through 2001. The spatial basis of the data grid is the US Geological Survey GTOPO30 digital elevation model. Data native format is an IDRISI geographic information system raster format, which is a simple ASCII matrix with a separate header file that is easy to use.
PARAGRAPH_XXO Initial temperature estimates were obtained by integrating upper air temperature data over both the model spatial domain and the required time period. Initial estimates were then modified by site elevation and proximity to the potential influence of maritime effects, implemented by modeling periods of low-level advection, and ice fields. 
PARAGRAPH_XXO Correlations between model estimates and independent surface observations from Meteorological Service of Canada weather stations and Polar Continental Shelf Project research camps are good, indicating consistent, reliable model operation. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO QUATERNARY DEPOSITS OF NEW SIBEIRIA ISLAND (RUSSIAN ARCTIC)

AUTHORS_XXO BASILYAN, ALEXANDER (1); Nikolskiy, Pavel A. (2)

AUTHOR_1_XXO (1) Geologycal Institute RAS, Moscow, Russia; basilyan@orc.ru
AUTHOR_2_XXO (2) Geologycal Institute RAS, Moscow, Russia

PARAGRAPH_1_XXO In 2000 and 2001, the reconnaissance were undertaken on New Sibeiria Island (East-Siberian Sea) within the Russian-US Project "Zhokhov-2000". In order to reveal the quaternary history of the New Siberia Island, development of fauna and flora and search for the ancient man traces, a significant part of the Island was investigated.
PARAGRAPH_XXO   
PARAGRAPH_XXO The surface of New Siberian Island is about completely covered by genetically different quaternary deposits. The only exception is the restricted outcrops of the underlying folded Meso-Cenozoic rocks.
PARAGRAPH_XXO  
PARAGRAPH_XXO In general, sequence of the quaternary deposits consists of marine deposits, which are overlayed by terrestrial deposits. Lower marine deposits are dislocated.  During the Quaternary, probably up to the beginning of the Late Pleistocene, the moste territory of the Island was submerged below the sea level. Three sedimentation cycles of marine deposits are identified by sea level oscillations. In the lower one, Arctica islandica (the Atlantic species of mollusks) is encountered. Its penetration such eastward shows climate warming in the early Quaternary. Numerous shells of Astarte (Tridonta) borealis and Astarte (Nicania) montagui are typical of the second cycle. An analysis of mollusk fauna and the character of lamination of enclosing deposits indicate a change of the sedimentation depth between 0 to 35-50 m. The cycles are separated by a peat interlayer formed under the sub-aquatic conditions. The sub-horizontal deposits of the regression part of the third cycle outcrope everywhere on New Siberian Island from the sea level up to the 20-30 m. Of mollusks in these deposits, only Portlandia arctica is encountered. This species can stand strong freshening.
PARAGRAPH_XXO In the Late Pleistocene, due to active tectonic movements and the eustatic sea regression accompanied with cooling, the shallow water parts of the shelf were dried. Simultaneously an Ice Complex deposits(dusty deposits with multiple ice wedges) have being forming at its surface following the development of erosion network. Terrestrial deposits are not dislocatet. Numerous late Pleistocene mammal bones are associated with these deposits. The age of fauna shows that Ice Complex deposition started at the beginning of late Pleistocene. The formation of an Ice Complex was completed around 10 kyr BP.

INSERT_PAGE_BREAK_HERE
TITLE_XXO LATE QUATERNARY PALEOENVIRONMENTAL CHANCE IN THE MELVILLE HILLS, N.W.T.

AUTHORS_XXO BEIERLE, BRANDON D. (1); Lamoureux, Scott F. (2); Dyke, Arthur S. (3)

AUTHOR_1_XXO (1) Department of Geography, Queen's University; brandon@lake.geog.queensu.ca
AUTHOR_2_XXO (2) Department of Geography, Queen's University; lamoureux@lake.geog.queensu.ca
AUTHOR_3_XXO (3) Geological Survey of Canada; adyke@nrcan.gc.ca

PARAGRAPH_1_XXO Preliminary results of sediment cores taken from a small lake located at 760 m asl, in the Melville Hills, NWT (69o04.86’ N 121o25.75’ W)  provide new information on the timing of deglaciation in the Bluenose Lake area, as well as one of the longest paleoenvironmental records in this region of the arctic.  A radiocarbon date of 9700 BP immediately post-dates the onset or organic sedimentation in the lake, confirming that the tops of the Melville Hills, which are suggested to have remained above the Laurentide ice limit during the Late Wisconsinan (Klassen, 1971), were ice free by the beginning of the Holocene.  While this does not confirm that the Melville Hills were unglaciated, it suggests that the effects of continental ice were minimal during the early Holocene.  By 9700 BP the Laurentide ice front stood about 200 km east of the site after depositing a broad belt of Younger Dryas age moraines around the lower east flank of the Melville Hills (Dyke et al., in review).
PARAGRAPH_XXO The Holocene paleoenvironmental record indicates a strong increase in autochthonous productivity near the end of the Younger Dryas. Organic carbon content increased by 20% between 10 000 and 9000 BP. Apparently Holocene climate varied in a quasi-cyclic manner with a period of 2500-3500 years. Variability is indicated by organic carbon, eolian sand, and moss fragment abundances. Intervals of low organic carbon correspond with intervals of increased deposition of well rounded quartz grains of medium to fine sand size, while intervals of high organic carbon correspond with more abundant moss fragments.
PARAGRAPH_XXO Clastic and organic sediment flux values, as well as grain size properties and the mass accumulation rate of sand deposited during periods of low organic carbon indicate that the low organic carbon content values did not result from dilution by increased sand influx.  This suggests that increased sand flux and decreased organic carbon content resulted from decreased lake productivity as well as increased eolian sediment deposition.  Recent studies from western Greenland (Willemse and Törnqvist, 1999) indicate that LOI organic carbon content values in arctic lakes are strongly correlated with the duration of ice cover, and therefore annual average temperature, suggesting colder conditions may have prevailed during the low LOI organic carbon phases.  This conclusion is also supported by chironomid-based water temperature reconstructions (Cwynar and Spear, 2001) which demonstrate a correlation between maximum summer water temperature and the organic carbon content of lake sediments.
PARAGRAPH_XXO The apparent cyclic nature of these alternating cool and warm intervals suggests that there may be some external forcing mechanism driving long-term climatic change in this region.  Although chronological control is currently limited (more dates are pending), recurrent cold intervals centered on ca. 1500, 4000, 7500 and 10500 BP may indicate external climate forcing by ocean or atmospheric circulation.  Although recent research has identified several processes which operate at comparable timescales (e.g. Bond et al., 1997; Darby et al., 2001), their role in this record cannot be assessed until dating control on this core is improved.  Ongoing analyses include pollen and diatoms, as well as increasing the sampling resolution of organic carbon measurements and macrofossil and sand grain counts.

REFERENCE_XXO Bond, G., Showers, W., Cheseby, M., Lotti, R., Almasi, P., deMenocal, P., Priore, P., Cullen, H., Hajdas, I., and Bonani, G. (1997). A pervasive millennial-scale cycle in North Atlantic Holocene and glacial climates. Science 278, 1257-1266.
REFERENCE_XXO Cwynar, L. C., and Spear, R. W. (2001). Lateglacial climate change in the White Mountains of New Hampshire. Quaternary Science Reviews 20, 1265-1274.
REFERENCE_XXO Darby, D., Bischof, J., Cutter, G., de Vernal, A., Hillaire-Marcel, C., Dwyer, G., McManus, J., Osterman, L., Polyak, L., and Poore, R. (2001). New record shows pronounced changes in Arctic Ocean circulation and climate. Eos, Transactions, American Geophysical Union 82, 601, 607.
REFERENCE_XXO Dyke, A.S., St-Onge, D.A., and Savelle, J.M. in review. Deglaciation of southwest Victoria Island and adjacent Canadian Arctic Mainland, Nunavut and Northwest Territories. Geological Survey of Canada, Map xxxxA, scale 1:500 000, with marginal notes, table and figures.
REFERENCE_XXO Klassen, R. W. (1971). Two surficial geology maps of Mackenzie District, NWT. Geological Survey of Canada, Open File Report 48, scale 1:250,000.
REFERENCE_XXO Willemse, N. W., and T„rnqvist, T. E. (1999). Holocene century-scale temperature variability from West Greenland lake records. Geology 27, 580-584.

INSERT_PAGE_BREAK_HERE
TITLE_XXO DIAGNOSTICS OF THE SUBPOLAR IONOSPHERE BY HF RADAR "BIZON"

AUTHORS_XXO BLAGOVESHCHENSKY, DONAT V. (1); Nozdrachev, Sergei V. (2)

AUTHOR_1_XXO (1)  St. Petersburg state university of aerospace instrumentation; dvb@aanet.ru
AUTHOR_2_XXO (2) The same; SEFO@ru.ru

PARAGRAPH_1_XXO 
PARAGRAPH_XXO The purpose of this paper is to show some possibilities of the BIZON facility as diagnostic means using the oblique backscatter (OBS) method in studying the subauroral ionosphere particularly during magnetic disturbed conditions when there is a complex and changeable picture of plasma distribution in the ionosphere.  The studied object is the subauroral ionosphere located above northern regions of Finland, Sweden, Norway and Russia.
PARAGRAPH_XXO 	 
PARAGRAPH_XXO At  present  the space area encompassed by the inner magnetosphere is still not clearly understood. This area in the vicinity of the Earth is coupled with the subauroral ionosphere. Here the main ionospheric trough is a major feature and component part. The poleward edge of the trough is the projection of the plasmapause on the ionosphere and for a steady state it conforms to the boundary of  diffusive auroral precipitation (BDP) of plasma layer particles. Several important geophysical phenomena on a ionospheric level are connected with a position of the BDP: convection boundary, longitudinal current boundary, sharp typical changes of ionospheric parameters in the F-region, electron concentration irregularities, radio waves and whistlers propagation changes and so on. 
PARAGRAPH_XXO The  BIZON is a two-channel version of the digital ionosonde of vertical/oblique incidence ionospheric sounders. This implement operates as a radar and enables to determine simultaneously the following characteristics:  frequency of signal reflected from the ionosphere, height (range) of reflecting layer of the ionosphere, amplitude and phase of received signal, Doppler shift and spectrum, wave polarization. The frequency range is 1 - 30 MHz, the transmitter power is 10 kW. The BIZON facility is installed at Gorkovskaya observatory near St. Petersburg. Receiving and transmitting antennas are oriented northward.
PARAGRAPH_XXO It is shown that the oblique backscatter method provides observers with useful information about the ionosphere simultaneously from areas of great sizes. Observation by the BIZON facility allows to study properly a complex picture of signals scattered from irregularities of  E- and F-regions of the ionosphere. Different types of oblique backscatter traces  -  discrete, diffusive, flat, with group delay, rapid arising and disappearing  -  reflect the essence of happened geophysical phenomena.

INSERT_PAGE_BREAK_HERE
TITLE_XXO RADIATION CLIMATOLOGY OF THE GREENLAND ICE SHEET DERIVED FROM IN-SITU MEASUREMENTS 1995-2002

AUTHORS_XXO BOX, JASON E.

AUTHOR_1_XXO CIRES/Greenland Climate Network; jbox@ice.colorado.edu

PARAGRAPH_1_XXO Visible and infrared radiation fluxes represent the primary energy source for melt and evaporation at the surface of the Greenland ice sheet. The annual cycle of hourly radiation measurements from twenty Greenland Climate Network (GC-Net) automated measurement sites were integrated into a radiation climatology of the Greenland ice sheet spanning 1995 to 2002. Using trend surface regression, a set of monthly radiation grids/maps for the Greenland ice sheet were created for: downwelling and reflected shortwave; downwelling and emitted longwave; net shortwave; net longwave; and net allwave radiation components. These models are validated with precise measurements from Swiss Camp at equilibrium line altitude (1150 m) and from the Summit of the ice cap (3208 m). Cloud frequency, effective cloud opacity, energy available for melt, and albedo grids/maps are available based on the radiation data. Other parameters such as temperature and specific humidity are also available as gridded models since they were required to construct the longwave radiation grids.

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE HUNT FOR THE LGM, NORTHEASTERN BAFFIN ISLAND:  ON THE TRAIL OF ELUSIVE COLD-BASED ICE

AUTHORS_XXO BRINER, JASON P. (1); Miller, Gifford H. (2)

AUTHOR_1_XXO (1) INSTAAR, Geological Sciences, University of Colorado; jason.briner@colorado.edu
AUTHOR_2_XXO (2) INSTAAR, Geological Sciences, University of Colorado; gmiller@colorado.edu

PARAGRAPH_1_XXO The extent and timing of Laurentide ice sheet (LIS) advances throughout the eastern Canadian Arctic have been poorly known largely due to a lack of last glacial maximum (LGM)-age radiocarbon ages for glacial deposits.  Recent approaches using lacustrine sediment cores and cosmogenic exposure dating have resulted in significant improvements in our understanding of LIS dynamics across southeastern Baffin Island.  However, unlike southeastern Baffin Island, where LGM ice left a limited moraine record, the wide coastal forelands of the Clyde region (Fig. 1), in northeastern Baffin Island, afford the opportunity to study a far more extensive glacial record of the last glaciation.  Thus far, new glacial mapping and cosmogenic exposure (CE) and radiocarbon dating in the Clyde region point towards a cold-based glacial style during the LGM, followed by warm-based receding ice:  
PARAGRAPH_XXO •  The oldest distinct ice limits on the Clyde foreland have CE ages that cluster in two groups of ~19 and ~13 ka (n=9).  These ice limits are defined not by moraines, but by a pattern of ice-marginal melt-water channels, indicating that cold-based ice was the dominant mode.  These melt-water channels grade to a marine limit ~90 m asl, which is far higher than previous studies have shown for the LGM.  
PARAGRAPH_XXO •  Sediments exposed across the foreland, including in the vast Clyde sea-cliffs, all date to beyond the range of radiocarbon dating.  These pre-LGM sediments are within the limit of LGM ice, but reveal no evidence of ever being overridden (no deformation or till cap).  Additional evidence of non-erosive LGM ice is the preservation of upland tors (>=65 ka, n=2) beneath the ice sheet as indicated by perched LGM-age erratics (n=3).  
PARAGRAPH_XXO •  Striated bedrock islands within Clyde fiord, and low-elevation lateral moraines in the outer part of the fiord, indicate that warm-based ice was receding from the fiord mouth by ~10 ka (n=7).  Melt-water channels connect some of these moraines to raised marine deltas, marking the marine limit at 40-50 m in the outer part of Clyde fiord.
PARAGRAPH_XXO •  Erratic-littered terrain beyond the outermost distinct ice limits on the Clyde foreland suggests that the foreland was once completely glaciated.  Two CE ages obtained from this area so far give mixed results: one erratic is ~13 ka and another is ~130 ka.  In addition, two CE ages of ~32 ka on moraine boulders at a high lateral location along outer Clyde fiord point toward the possibility of finding a record of pre-LGM glaciation.  
PARAGRAPH_XXO Our old tor ages suggest that the highly weathered, high elevation surfaces along northeastern Baffin Island are ancient features unmodified by glaciation, and did not form post-glacially.  However, our finding of young erratics on these old landscapes suggests that the use of relative weathering as a criterion for determining ice extent is not valid.  Overall, our findings of more extensive ice and higher relative sea levels than previously envisioned are consistent with other recent findings in the Canadian High Arctic and elsewhere.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/54-1.gif

CAPTION_XXO Fig 1.  Digital elevation map (black = high elevation) showing fiords, coastal mountain range, and coastal forelands of northeastern Baffin Island.  The inset map shows the outline of the Laurentide ice sheet on North America; Baffin Island is highlighted in dark gray, and the box is the area of figure 2.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/54-2.gif

CAPTION_XXO Fig 2.  Geochronologic information and reconstructed ice margins of the Laurentide ice sheet on the Clyde foreland.  The outlet glaciers came from both the Clyde fiord (bottom) and the Ayr Lake valley (middle). 

INSERT_PAGE_BREAK_HERE
TITLE_XXO MULTI-PROXY EVIDENCE FOR RAPID AND PRONOUNCED LATE GLACIAL CLIMATE CHANGE IN THE AHKLUN MOUNTAINS, SOUTHWESTERN ALASKA

AUTHORS_XXO BRINER, JASON P. (1); Hu, Feng Sheng (2); Kaufman, Darrell S. (3); Manley, William F. (4); Axford, Yarrow L. (5); Werner, Al (6); Caffee, Marc (7)

AUTHOR_1_XXO (1) INSTAAR and Geological Sciences, University of Colorado; jason.briner@colorado.edu
AUTHOR_2_XXO (2) Department of Plant Biology, University of Illinois; fshu@life.uiuc.edu
AUTHOR_3_XXO (3) Dept. of Geology and Dept. of Environmental Sciences, Northern Arizona University; darrell.kaufman@nau.edu
AUTHOR_4_XXO (4) INSTAAR, University of Colorado; william.manley@colorado.edu
AUTHOR_5_XXO (5) National Snow and Ice Data Center, CIRES, University of Colorado; axford@nsidc.org
AUTHOR_6_XXO (6) Dept. of Earth and Environment, Mt. Holyoke College; awerner@mtholyoke.edu
AUTHOR_7_XXO (7) PRIME lab and Dept. of Physics, Purdue University; mcaffee@physics.purdue.edu

PARAGRAPH_1_XXO Determining the spatial and temporal pattern of abrupt climate events, such as the Younger Dryas event (YD; ~12.9 to 11.6 cal ka), is key to understanding interactions among the components of the climate system and for discerning regional climate teleconnections.  Two independent records of late-glacial climate change in the Ahklun Mountains, southwestern Alaska, suggest that this region experienced rapid and pronounced climate oscillations coincident with the YD:  1) An expansion of alpine glaciers during the Mt. Waskey advance produced an extraordinarily well-defined end moraine system.  Eleven cosmogenic 10Be and 26Al exposure ages on moraine boulders, combined with radiocarbon ages from a lake core upvalley of one of the moraines, suggest that the advance culminated between 12.4 and 11.0 cal ka, sometime during, or shortly following, the YD.  Reconstructed equilibrium line altitudes (ELAs) for the Mt. Waskey advance are 80 ± 30 m below modern values, and are 25 to 40% of the full glacial lowering.  2) Pollen assemblages, biogenic-silica, and organic-carbon contents in a sediment core from Nimgun Lake (~100 km west of Mt. Waskey) indicate pronounced changes in terrestrial vegetation, aquatic productivity, and landscape stability coincident with the YD.  For example, Betula shrub tundra abruptly reverted to herb tundra at the onset of the YD, and became re-established at the end of the YD.
PARAGRAPH_XXO The ecological changes recorded at Nimgun Lake likely reflect a climatic cooling and a decrease in effective moisture during the Younger Dryas.  Using an empirical relationship between climate and the ELA of modern glaciers, and assuming that it was 30 to 50% drier during the Younger Dryas, then the ELA depression of 80 m for the Mt. Waskey advance could correspond to a temperature depression of ~1.5°C to 3.5 °C.  These values are consistent with published modeling results for the North Pacific region during the YD.  Thus, data from the Ahklun Mountains add to a growing body of evidence that the North Pacific region experienced pronounced climate oscillations coincident with the North Atlantic YD.  Taken together, these results point towards a tightly coupled ocean-atmospheric system.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/55-1.gif

CAPTION_XXO Fig 1.  Map of Alaska showing the Ahklun Mountains.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/55-2.gif

CAPTION_XXO Fig 2.  Cosmogenic exposure ages of moraine boulders deposited during the Mt. Waskey advance.  Error bars span the upper limit of the 1 S.D. range of ages calculated using maximum estimates of snow cover and surface erosion, and the lower limit of the 1 S.D. range using zero erosion and snow cover.  Plain text sample IDs represent an average exposure age for samples that have both 10Be and 26Al ages, bold text sample IDs are 10Be ages, and italicized sample IDs are 26Al ages.  Also shown is the Younger Dryas chronozone (12.9-11.6 ka), the calibrated radiocarbon age (2 S.D. range) from Waskey Lake (minimum-limiting age for the Mt. Waskey advance), and the maximum 1 S.D. weighted mean moraine stabilization age range.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/55-3.gif

CAPTION_XXO Fig 3.  Comparisons of organic carbon (OC), biogenic silica (BsiO2), total mineral matter other than biogenic silica (MM), selected pollen types, and pollen DCA axis 1 scores from Nimgun Lake with the d18O record from GISP2.

INSERT_PAGE_BREAK_HERE
TITLE_XXO SMALL-SCALE DYNAMICS OF SEA ICE IN THE BERING SEA: A REMOTE SENSING AND NUMERICAL MODEL INVESTIGATION

AUTHORS_XXO BUMP, JOSEPH  K. (1); Lovvorn, James R. (2)

AUTHOR_1_XXO (1) University of Wyoming; jkbump@uwyo.edu
AUTHOR_2_XXO (2) University of Wyoming; lovvorn@uwyo.edu

PARAGRAPH_1_XXO Global warming effects on sea-ice/animal relations are of special interest because an array of birds and mammals that depend on sea-ice have declined in recent years.  Winter sea ice in the Bering Sea is important habitat for a number of top predators such as seaducks, walruses, seals, and whales.  The time-dependent, spatial mosaic of ice and open water is critical to these surface-constrained endotherms for feeding, breathing, resting, escape from predators, and reproduction.  Despite the extreme importance of ice conditions to these animals, almost no methods have been developed to characterize the structure of leads (open water areas) from remotely-sensed images to evaluate trends in ice habitat at small scales relevant to these animals.  Based on field observations from an icebreaker and analysis of satellite SAR (synthetic aperture radar) images, we present methods to quantify the dispersion, duration, and orientation of leads in sea ice during winter in the nothern Bering Sea.  Our methods generate frequency distributions of lead characteristics that can be sampled in simulation models of foraging. Our goal is to develop predictive models of small-scale ice characteristics based on weather and preceding sea-ice conditions. Such models will directly tie ice conditions to the population energetics of affected animals, and identify key aspects of lead structure that constrain animal distributions.  The methods developed here are applicable to ice-dependent species throughout polar and subpolar regions.  
PARAGRAPH_XXO   

INSERT_PAGE_BREAK_HERE
TITLE_XXO LATE WISCONSIN GLACIAL LIMITS IN SOUTHERN SOUTHEASTERN ALASKA, AS INDICATED BY A NEW BATHYMETRIC MAP

AUTHORS_XXO CARRARA, PAUL E. (1); Ager, Thomas A. (2); Baichtal, James F. (3); Van Sistine, Darren (4)

AUTHOR_1_XXO (1) U.S. Geological Survey; pcarrara@usgs.gov
AUTHOR_2_XXO (2) U.S. Geological Survey; tager@usgs.gov
AUTHOR_3_XXO (3) U.S. Forest Service; jbaichtal@fs.fed.us
AUTHOR_4_XXO (4) U.S. Geological Survey; dsistine@usgs.gov

PARAGRAPH_1_XXO LATE WISCONSIN GLACIAL LIMITS IN SOUTHERN SOUTHEASTERN ALASKA, AS INDICATED BY A NEW BATHYMETRIC MAP
PARAGRAPH_XXO Carrara, P.E.1, Ager, Thomas A.1, Baichtal, James F.2, Van Sistine, Darren1 , 1U.S. Geological Survey, Mail Stop 980, Box 25046, Denver Federal Center, Denver, CO 80225 (pcarrara@usgs.gov), 2U.S.D.A. Forest Service, Tongass National Forest, P.O. Box 19001, Thorne Bay, AK 99919 
PARAGRAPH_XXO An ice extent during the late-Wisconsin glaciation (ca. 26,000 to 13,000 yr BP) in southern southeastern Alaska, more restricted than previous estimates, is indicated by evidence revealed by a new bathymetric map. The map was prepared from a digital database of water depths and contoured, thus allowing topographic depiction of submarine features, including moraines, deep glacially scoured troughs, and submarine slides. During the late-Wisconsin glaciation the Cordilleran glacier complex formed vast ice fields along the crest of the Coast Mountains. As these glaciers flowed west toward the Gulf of Alaska they were joined by local glaciers originating on the higher reaches of the islands of the Alexander Archipelago (Mann and Hamilton, 1995). This extensive volume of ice was channeled into the present-day fjords that formed major outlet glaciers, such as the glaciers that occupied Chatham Strait and Dixon Entrance. <br>The bathymetric map indicates that major outlet glaciers in Chatham Strait, Sumner Strait, and Dixon Entrance eroded deep (>500 m in places) troughs extending to the western edge of the continental shelf. For instance, the glacier that flowed into the Dixon Entrance trough advanced to the edge of the continental shelf; its retreat began sometime after 15,000 to 16,000 BP and the trough was free of ice by 13,000 BP (Barrie and Conway, 1999). On the shelf the Sumner Strait trough is not a well-defined feature and appears to be partly filled with sediments. It may be pre-late Wisconsin in age. In addition to these major troughs, smaller glacial troughs and moraines are discernable at several locations on the inner continental shelf. Although the exact extent of the late Wisconsin glaciers in southeastern Alaska is poorly known, the new bathymetric map indicates that most late Wisconsin glaciers along the western edge of the Alexander Archipelago did not extend to the shelf edge as some previous studies suggested (e.g. Pewe, 1975). <br>In addition to the bathymetric map possible ice-free areas in southeast Alaska during the late-Wisconsin glaciation were identified by analyses of aerial photographs, topographic maps, and large-scale nautical charts, as well as a review of previous literature, and reconnaissance fieldwork. These ice-free areas include, 1) parts of the inner continental shelf exposed by the lowering of sea level during the late Wisconsin, 2) parts of the westernmost islands of the Alexander Archipelago (Worley, 1980), 3) unglaciated ocean-facing slopes and forelands, and 4) nunataks, present on many of the high mountains of Admiralty, Baranof, Chichagof, and Prince of Wales Islands.<br>The bathymetric map shows extensive areas of the inner continental shelf that were subaerially exposed during the last glaciation, when global sea level was about 125 m below present sea level. These ice-free areas on the continental shelf may include; an area adjacent to the southern part of Baranof Island in the vicinity of Whale Bay (830 sq. km), an area west and south of Coronation Island (620 sq. km), and a large area west and adjacent to Noyes and Baker Islands (1150 sq. km). Several of the outer islands apparently were not overridden by continental ice, including Forrester, Coronation, and Warren. Although the latter two islands probably supported small local glaciers, it appears that parts of these islands were ice-free. Unglaciated ocean-facing slopes and forelands were probably present on Noyes, Baker, Sumez, and Dall Islands. <br>These unglaciated areas may have been important refugia for at least the hardiest elements of the southeastern Alaska flora and fauna during the late Wisconsin and as centers for biotic dispersal upon deglaciation (Heusser, 1960, 1989; Worley, 1980). Furthermore, these refugia may have served as "stepping stones" for human migration along the coast of North America (Heusser, 1960, 1989; Dixon, 2001; Mandryk et al., 2001).   <br>The bathymetric map also shows what may be a massive submarine slide on the edge of the continental shelf west of Baker and Noyes Islands that may have been triggered by a large-magnitude earthquake along the Fairweather-Queen Charlotte fault. Two possible submarine volcanoes can also be seen south of Coronation Island and west of Noyes Island.

REFERENCE_XXO Barrie, J.V., and Conway, K.W., 1999, Late Quaternary glaciation and postglacial stratigraphy of the northern Pacific margin of Canada. Quaternary Research, v. 51, p. 113-123.
REFERENCE_XXO Dixon, E.J., 2001, Human colonization of the Americas: timing, technology, and process. Quaternary Science Reviews, v. 20, p. 277-299.
REFERENCE_XXO Heusser, C.J., 1960, Late-Pleistocene environments of north Pacific North America.: an elaboration of late-glacial and post-glacial climatic, physiographic, and biotic changes. Special Publication no. 35, American Geographical Society, 308 p. 
REFERENCE_XXO Heusser, C.J., 1989, North Pacific coastal refugia - the Queen Charlotte Islands in perspective. In Scudder, G.G.E. and Gessler, N., (eds.). The outer shores, proceedings of the Queen Charlotte Islands 1st International Symposium, University of British Columbia, p. 91-106. 
REFERENCE_XXO Mandryk, C.A.S., Josenhans, H., Fedje, D.W., Mathewes, R.W., 2001, Late Quaternary paleoenvironments of northwestern North America: implications for inland versus coastal migration routes. Quaternary Science Reviews, v. 20, p. 301-314. 
REFERENCE_XXO Mann, D.H. and Hamilton, T.D., 1995, Late Pleistocene and Holocene paleoenvironments of the north Pacific coast. Quaternary Science Reviews, v. 14, p. 449-471. 
REFERENCE_XXO Pewe, T.L., 1975, Quaternary geology of Alaska. U.S. Geological Survey Professional Paper 835, 135 p.
REFERENCE_XXO Worley, I, 1980, Ancient environments and age of non-glaciated terrain in southeastern Alaska. National Geographic Society Research Reports (1971), p. 733-747.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/34-1.jpg

CAPTION_XXO Fig 1.  Map of southern southeastern Alaska showing late Wisconsin ice limit

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE CONTRIBUTION OF ARCTIC GLACIERS TO THE WATER CYCLE

AUTHORS_XXO CARTER, CARISSA L. (1); Dyurgerov, Mark B. (2)

AUTHOR_1_XXO (1) INSTAAR; carissa.l.carter@noaa.gov
AUTHOR_2_XXO (2) INSTAAR; dyurg@tintin.colorado.edu

PARAGRAPH_1_XXO Glacier contribution to the Arctic Ocean has increased from 1960 to the present in response to climate change.  Using updated time series (from Dyurgerov, 2002) for about 110 glaciers in the Arctic and Pan-Arctic totaling an area of 330,302 km2, we calculated temporal and spatial changes as well as variability in the mass balance of Arctic glaciers.  We also approximated the cumulative contribution of glaciers relative to river runoff into the Arctic Ocean.  The Greenland ice sheet is not part of our analysis, but individual ice caps around Greenland are included. 
PARAGRAPH_XXO The role of glaciers in the Arctic water cycle is unique.  In many cases, glacial runoff and river runoff can be analyzed separately.  Available river runoff data from the Arctic covers areas where glacial meltwater contribution to river systems is negligible.  The main Arctic rivers in Siberia, Eastern Europe, and North America, dominant fresh-water contributors to the Arctic Ocean, have very small glacial components. Conversely, more than 95% of glacier area in the Arctic covers archipelagoes (Canadian, Russian, and Svalbard) or other regions where no permanent gauging stations exist (R-ArcticNET, 2001), and therefore no river runoff data is available.  This means that in the analyzed river discharge data, glacial meltwater is not included.
PARAGRAPH_XXO Changes in ice volume show large spatial variability, from mm in the Canadian Arctic to meters in Scandinavia, Iceland, and Svalbard (Fig. 1).  Yearly volume fluctuations correspond to regional climate shifts.  Glaciers in maritime climates, including Scandinavia and parts of Western Svalbard, have the largest variability in ice volume.  In cold and dry regions such as the Canadian Arctic, year-to-year variability is small.  
PARAGRAPH_XXO Volume loss in Arctic glaciers is accelerating.  From 1960-76 glaciers were near a steady-state regime. The first shift towards accelerating mass loss occurred in 1976-77, the second, stronger shift, started at the end of the 1980s and continues today (Fig. 2) (McCabe et al., 2000 and Dyurgerov and Meier, 2000).  Both shifts coincide with changes in atmospheric circulation patterns, the Arctic Oscillation, and increases in annual air temperature in the Northern Hemisphere.  
PARAGRAPH_XXO Using data from more than 30 glaciers in the Pan-Arctic with relatively long-term mass balance records, we calculated the change in total glacier area over the last decades (Fig. 3).  In sum, these glaciers lost approximately 40 km2, about 0.4% of their original area in 1961.  Extrapolating these measured changes to other areas of small glaciers in the Arctic, the total area loss of glaciers in the Pan-Arctic is about 1300 km2.
PARAGRAPH_XXO We used river discharge data from the R-ArcticNET Hydrographic Data Network to calculate the average river runoff for the entire Arctic, in particular for regions where there are no glaciers, or where glacier area is negligibly small, in order to compare the contributions of both components to the Arctic Ocean.  Annual glacial meltwater runoff (inflow) is small compared to annual runoff from the main Arctic rivers.  However, the cumulative contribution of Arctic glaciers to the Arctic Ocean exceeds the net contribution of large Arctic rivers since 1961 (Fig. 4).  We define glacier contribution as volume change: ÂDV, and river runoff contribution as a cumulative departure from the average: Â(Ri - <R>), where Ri is the annual runoff in a year I, and <R> is the average annual runoff from 1961-90.  Until the end of the 1970’s, river runoff contribution was much larger than the cumulative Arctic glacier contribution, but after 1980 glacier contribution to the Arctic Ocean exceeded river contribution.  
PARAGRAPH_XXO Temporal variability in glacier volume loss exceeds the year-to-year variability of river runoff (coefficient of variation is 4%) by an order of magnitude.  This implies that in extreme climate conditions, glaciers intensify the water cycle in the Arctic.
PARAGRAPH_XXO In conclusion, these comparisons show that the cumulative effect of Arctic glacier volume loss (Greenland ice sheet not included) exceeded the cumulative contribution of river runoff to the Arctic Ocean from the early 1980’s to 1998.  This indicates that river contribution to the Arctic Ocean and glacier contribution to the Arctic Ocean are intimately related to each other and to climate change, but determining the extent of the interplay of these variables will require further study. 

REFERENCE_XXO Dyurgerov, M. B., 2002: Glacier Mass Balance and Regime: Data of
REFERENCE_XXO Measurements and Analysis. INSTAAR Occasional Paper #55, 268 pp., and
REFERENCE_XXO http://instaar.colorado.edu/other/occ_papers.html)
REFERENCE_XXO Dyurgerov, M. B. and Meier, M. F., 2000: Twentieth century climate change:
REFERENCE_XXO Evidence from small glaciers. Proceedings of National Academy of Sciences,
REFERENCE_XXO USA, 97, (4): 1406-1411.
REFERENCE_XXO McCabe, G. J., Fountain, A. G., and Dyurgerov, M. B., 1999: Effects of the
REFERENCE_XXO 1976-77 climate transition on the mass balance of Northern Hemisphere
REFERENCE_XXO glaciers. Arctic, Antarctic and Alpine Research, 32 (1): 64-72.
REFERENCE_XXO R-ArcticNET: A Regional Hydrographic Data Network for the Pan-Arctic Region. 
REFERENCE_XXO (v.2.1), NSIDC, 2001.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/50-1.gif

CAPTION_XXO Fig 1.  Spatial and temporal variability in glacier mass balance in select Arctic regions.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/50-2.gif

CAPTION_XXO Fig 2.  Volume change in select Arctic regions.  Vertical lines indicate major climate shifts.  

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/50-3.gif

CAPTION_XXO Fig 3.  Surface area change for 30 selected glaciers.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/50-4.gif

CAPTION_XXO Fig 4.  Cumulative contribution of glaciers and rivers to the Arctic Ocean.  Glacier contribution is volume change, and river contribution is the cumulative departure from the average runoff.

INSERT_PAGE_BREAK_HERE
TITLE_XXO RECENT STUDIES OF THE GLACIERS OF THE CAMPO DE HIELO SUR IN CHILEAN/ARGENTINE PATAGONIA

AUTHORS_XXO Casassa, Gino (1); Rivera, Andres (2); Sepulveda, Francisco (3); SINCLAIR, ROLF (4)

AUTHOR_1_XXO (1) CECS/Valdivia, Chile; gcasassa@cecs.cl
AUTHOR_2_XXO (2) CECS/Valdivia, Chile; arivera@cecs.cl
AUTHOR_3_XXO (3) CECS/Valdivia, Chile; fsepulveda@cecs.cl 
AUTHOR_4_XXO (4) CECS/Valdivia, Chile; rolf@santafe.edu

PARAGRAPH_1_XXO 	
PARAGRAPH_XXO This poster will describe the recent International Expedition to study the "Southern Ice Field", located in Chile and Argentina at approximately 50 deg. S. This ice field is the one of the largest bodies of ice in the world outside the polar regions, yet it is largely unstudied so far. It has more than 60 outlet glaciers and several hundred minor glaciers that drain the ice to the Pacific Ocean and to the large eastern piedmont lakes.

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE HOLOCENE DEVELOPMENT OF THE ICELANDIC BIOTA AND ITS PALAEOCLIMATIC SIGNIFICANCE

AUTHORS_XXO CASELDINE, CHRIS J. (1); Langdon, Pete G. (2); Dinnin, Mark H. (3); Hendon, Dawn M. (4)

AUTHOR_1_XXO (1) University of Exeter, UK; C.J.Caseldine@exeter.ac.uk
AUTHOR_2_XXO (2) University of Exeter, UK; P.G.Langdon@exeter.ac.uk
AUTHOR_3_XXO (3) University of Exeter, UK; M.H.Dinnin@exeter.ac.uk
AUTHOR_4_XXO (4) University of Exeter, UK; D.Hendon@exeter.ac.uk

PARAGRAPH_1_XXO The Holocene development of the Icelandic biota is reviewed, with specific reference to four major proxies of environmental change (pollen, Coleoptera, testate amoebae and chironomids). Research on Holocene landscape development in Iceland has focused principally on the reconstruction of glacial histories (Stotter et al. 1999), with a rather limited examination of the biota of the country despite almost half a century of pollen-analytical studies (Hallsdottir 1995). Apart from pollen and plant macrofossils, subfossils used elsewhere as proxies for reconstructing Holocene environments have been little employed. Coleoptera have been studied from archaeological and largely post-settlement sediments (Buckland et al. 1995), but testate amoebae (Protozoa: Rhizopoda) and chironomids (non-biting midges) have yet to be examined in detail in a Holocene context. The aim of this paper is to review the past work and assess the potential contribution such proxies can make to understanding the evolution of the Icelandic landscape throughout the Holocene. Two particular issues form the context of this overview: 1) The characteristics of the biota representative of island development, particularly the origins, probable immigration routes and timing of colonisation of species, and the way they responded to forcing factors through the Holocene; and, 2) The potential value of the different records as proxies of environmental, and especially climatic change. Because of its location close to major atmospheric and oceanic boundaries understanding the terrestrial response of the biota of Iceland to change is essential in estimating the nature of past climates. The value of this record is heightened by the potential chronological control provided by the tephrochronological dating framework and the growing body of information concerning the Holocene patterns of sea-surface temperature change arising from extensive studies of offshore marine sediment records (Eiriksson et al. 2000; Andrews et al. 2001).

REFERENCE_XXO Andrews, J.T., Caseldine, C.J., Weiner, N. and Hatton, J.M. 2001. Causes of Late Holocene (ca. 4ka) marine and terrestrial environmental change in Reykjarfjordur, N.Iceland: climate and/or settlement? Journal of Quaternary Science 16, 133-143.
REFERENCE_XXO Buckland, P. C., Edwards, K. J., Blackford, J., Dugmore, A. J., Sadler, J. P. and Sveinbjarnardottir, G. (1995) A question of Landnam: pollen, charcoal and insect studies on Papey, eastern Iceland pp.245-264 in Butlin, R. and Roberts, N. (eds.) Ecological Relations in Historical Times. Institute of British Geographers. Oxford: Blackwell.
REFERENCE_XXO Eir›ksson, J., Knudsen, K.L., Haflidason, H. and Henriksen, P. 2000. Late-glacial and Holocene palaeoceanography of the North Icelandic shelf. Journal of Quaternary Science 15, 23-42.
REFERENCE_XXO Hallsdottir, M. 1995. On the pre-settlement history of Icelandic vegetation. Buvisindi 9, 17-29.
REFERENCE_XXO Stotter, J., Wastl, M., Caseldine, C.J. and Haberle, T. 1999. Holocene Palaeoclimatic reconstruction in Northern Iceland: approaches and results. Quaternary Science Reviews 18, 457-474.

INSERT_PAGE_BREAK_HERE
TITLE_XXO HOLOCENE RECORDS OF PALEOCEANOGRAPHIC AND CLIMATIC VARIABILITY FROM THE N. ICELAND CONTINENTAL SHELF.

AUTHORS_XXO CASTANEDA, ISLA S. (1); Smith, Laryn M. (2); Kristjansdottir, Greta B. (3); Andrews, John T. (4); Anderson, David M. (5)

AUTHOR_1_XXO (1) Instaar; isla_sarita@hotmail.com
AUTHOR_2_XXO (2) Instaar; lmiksmith@hotmail.com
AUTHOR_3_XXO (3) Instaar; gbk@colorado.edu
AUTHOR_4_XXO (4) Instaar; andrewsj@spot.colorado.edu
AUTHOR_5_XXO (5) Noaa and Instaar; David.M.Anderson@noaa.gov

PARAGRAPH_1_XXO In recent years, an increasing number of high-resolution Holocene studies have focused attention on century to millennial scale climatic variations.  These climatic variations are particularly evident in the North Atlantic and Arctic regions, as these areas are highly sensitive to both natural and human-induced climate change (Overpeck et al., 1997).  In this study, we use oxygen isotope and total carbonate data from marine sediment cores to construct a high-resolution Holocene history of the N. Iceland region. Based on this data, we divide the Holocene history of the N. Iceland continental shelf into three main stages: 1) deglaciation of the NW Peninsula (until ~9000BP), 2) early Holocene warming (9000-5000BP), and 3) neoglacial cooling (5000BP-present).
PARAGRAPH_XXO In 1997, a series of piston and gravity cores were collected from the Icelandic continental shelf aboard the Bjarni Saemundsson (B997 cruise).  In this study, nine cores from the N. Icelandic continental shelf are examined (B997-317, -321, -324, -327, -328, -329, -330, -331, and –332) as they contain records of Holocene climatic variability (Fig. 1).  The lithofacies present in the majority of the cores examined in this study is an olive black sandy silt.  This lithofacies represents the interval from ~8000-0BP.  Another lithofacies, an olive black silty clay, is present in the older cores examined in this study and represents the interval from >9500-8000BP.  Age-control in all cores is provided by AMS 14C dating of mollusks and foraminifera, and by tephrochronology.  An important tephra marker, the Saksunarvatn Ash, has been identified in several of the cores examined in this study.  In this study a 400-year marine reservoir correction is applied to all ages.  In cores 329 and 332, applying a 400-year marine reservoir correction predicts the age of the Saksunarvatn ash as 9080 and 9000BP, respectively.
PARAGRAPH_XXO Of the nine cores examined in this study, only one core (B997-324) contained both planktic and benthic foraminifera in enough abundance to conduct oxygen isotope analysis on both types.  In core 324, stable isotopes were analyzed on two benthic species, Melonis barleeanus (formerly M. zaandamae) and Turborotalia quinqueloba, and on the planktic species N. pachyderma (s).  In cores 317, 321, and 327, the planktic species N. pachyderma (s) was used for oxygen isotope analysis as no benthic foraminifera occurred in enough abundance.  In the nearshore cores (B997-328, -329, -330, -331, and –332), few if any planktic foraminifera were noted, therefore, oxygen isotope analyses were made on the epifaunal benthic species Cibicides lobatulus. 
PARAGRAPH_XXO Cores 324, 329 and 332 extend back to >9500BP, and capture the deglaciation of the NW Peninsula of Iceland.  During this interval, sedimentation rates are extremely high (>6m/kyr in the nearshore cores), and oxygen isotope values indicate a rapid warming (Fig. 2).  Total carbonate values also indicate a rapid warming occurring during this interval.  In cores 329 and 332, sedimentation rates slow somewhat after ~9000BP, and suggest that the deglaciation of the NW Peninsula was completed by ~9000BP.  Additionally, oxygen isotopes indicate warming trends until ~9000BP, and slight cooling occur after this time.  Sedimentation rates remain high in both cores 329 and 332 until ~8000BP, and the high sedimentation during this period may be due to increased erosion rates on land following the retreat of ice caps.
PARAGRAPH_XXO The interval from 9000-5000BP, is marked by a general warming trend (Fig. 2).  This warming is recognized in the d18O and total carbonate records.  Additionally, foraminiferal assemblage data from core 329 supports warming during this interval with   numbers of benthics/gram reaching their highest values, and numbers of agglutinated foraminifera decreasing throughout the interval.  Stotter et al. (1999) do not note any glacier advances during this time and Eiriksson et al. (2000) also characterize the interval from 9000-6200BP as a period when the Irminger Current had an increased influence on the N. Iceland shelf.  Oxygen isotope values reach their lightest values in the interval from 7000-5000BP, suggesting that this was the warmest time of the Holocene.  In core 330, following a broad light interval in the early Holocene, d18O values rapidly increase between approximately 5500-4000 BP and indicate a return to cooler conditions.
PARAGRAPH_XXO The interval from ~5000BP to the present is the interval best documented in this study.  Within this interval, cores 328 and 330 have a high sampling resolution (approximately one sample per 64 years).  Additionally, in these two cores, the total carbonate data correlates highly to the oxygen isotope data, suggesting that the d18O values are due to changes in temperature and not salinity.  If significant changes in salinity had occurred, then we would expect that the d18O and total carbonate records would not exhibit the same trends.  
PARAGRAPH_XXO In the past 5000BP, the bottom water temperatures of the N. Iceland continental shelf have varied considerably (Fig. 3).  The overall trend over the past 5000BP is a cooling trend toward the present.  In the past 5000BP, oxygen isotope and total carbonate data indicate cold periods at ~3800-3600BP, and from ~600-200BP (the Little Ice Age).  Warmer intervals occurred at 3400-3200B, and at 1800-1200BP.  In the interval from 3000-2000BP, lesser magnitude warming and cooling intervals are apparent.   In the past 5000BP, several records used in our study show shifts in d18O values of up to 0.5 per mil.  If we are correct in assuming that the d18O signal at several of our coring sites is responding mainly to changes in temperature, then in the past 5000BP, bottom water temperatures of the N. Iceland continental shelf have varied by up to 2 degrees C.  

REFERENCE_XXO Eiriksson, J., Knudsen, K.L., Haflidason, H., and Henriksen, P., 2000a.  Late-glacial and Holocene paleoceanography of the North Icelandic shelf.  Journal of Quaternary Science: 15, 23-42.
REFERENCE_XXO Overpeck, J., Hughen, K., Hardy, D., Bradley, R., Case, R., Douglas, M., Finney, B., Gajewski, K., Jacoby, G., Jennings, A., Lamoureux, S., Lasca, A., MacDonald, G., Moore, J., Retelle, M., Smith, S., Wolfe, A., and Zielinski, G., 1997.  Arctic Environmental Change of the Last Four Centuries: Science, v. 278, p. 1251-1256.
REFERENCE_XXO Poole, D.A.R., Trond, Dokken, M., Hald, M., and Polyak, L., unpublished paper.  Stable isotope fractionation in recent benthic foraminifera from the Barents and Kara Seas.
REFERENCE_XXO St„tter, J., Wastl, M., Caseldine, C., and H¾berle, T., 1999.  Holocene paleoclimatic reconstruction in northern Iceland: approaches and results.  Quaternary Science Reviews: 18, 457-474.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/45-1.jpg

CAPTION_XXO Fig 1.  Location of B997 cores examined in this study.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/45-2.jpg

CAPTION_XXO Fig 2.  Oxygen isotope records from cores 329, 330, and 332 during the interval from >9000-5000BP.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/45-3.jpg

CAPTION_XXO Fig 3.  Oxygen isotope data from cores 328 and 330 from 5000BP to the present.  Oxygen isotope data has been smoothed in order to make trends in the data more visible.

INSERT_PAGE_BREAK_HERE
TITLE_XXO A COMPARISON OF 45 YEARS OF REGIONAL RIVER DISCHARGE RECORDS AND SUBANNUAL EVENTS IN VARVED SEDIMENTS FROM TWO LAKES IN WHITE PASS, BRITISH COLUMBIA/ALASKA

AUTHORS_XXO COCKBURN, JACLYN (1); Lamoureux, Scott F. (2)

AUTHOR_1_XXO (1) Department of Geography, Queen's University; jackie@lake.geog.queensu.ca
AUTHOR_2_XXO (2)  Department of Geography, Queen's University; lamoureux@lake.geog.queensu.ca

PARAGRAPH_1_XXO Annually laminated (varved) sediments are potentially useful proxies for watershed hydrometeorological behaviour.  Varve formation in a lake with primarily clastic, allochthonous inputs is controlled by seasonal and subseasonal sediment delivery.  Process studies have correlated meteorological (temperature and precipitation) and river discharge records to varve thickness, demonstrating the climatic influences on annual sediment accumulation (Hardy et al., 1996).  Individual hydrological events are also identifiable in detailed examinations of subannual rhythmites within a varve (Lamoureux, 2000).  In this study, varves from two adjacent catchments located at White Pass, British Columbia are used to evaluate the preservation and reproducibility of subannual sedimentary events based on a comparison with 45 years of daily river discharge records.  Specifically, the ability to discern subannual sedimentary events within each varve record is examined and the hydrometeorological thresholds that produce subannual rhythmites are estimated.  
PARAGRAPH_XXO The inflow to Summit Lake (59°39’N, 135°08’W, 28 km^2 watershed, 17% glacial cover) is dominated by substantial spring nival melt, summer glacial melt and autumn rainstorms although limited field observations suggest that sediment transport and deposition occurs primarily during glacial melt and autumn rainstorms.  The sediment cores used in this study are from the main proximal basin and include a long vibracore and surface core (water depth 27 m).  The cores were subsampled for thin sections and grain size determination.
PARAGRAPH_XXO Meadow Lake (unofficial name, 59°41’N, 135°05’W) is an isolated basin of Summit Lake, northeast and distal to the main basin.  The creek flowing into Meadow Lake drains a 14 km^2 watershed with 7% glacial cover.  Meadow Lake is much smaller than Summit Lake (Meadow is 300 x 50 m and 10 m deep compared to Summit 7.5 x 0.3 km and 40 m deep) and field observations indicate that the majority of sediment deposition occurs during spring melt.  A long vibracore and a surface core (water depth 10 m) were retrieved and subsampled for thin sections and physical characterization.
PARAGRAPH_XXO The varve chronologies developed for each lake were compared year-by-year with discharge records from several rivers in the region in order to correlate river discharge events with subannual laminae in each varve.  A comparison of the results for each lake record confirmed that there were differences in the types of sedimentary events preserved in each lake.  Temperature and precipitation records from stations in British Columbia, Yukon and Alaska, were also matched to the combined river discharge and sedimentary event data to determine the meteorological conditions associated with the preserved river discharge events.  
PARAGRAPH_XXO The expectation was that both lakes would preserve nival and glacial melt and late autumn rainstorm events as subannual laminae within a varve.  However, because Meadow Lake is smaller, shallower and has a short residence time, it does not trap clay efficiently, as is evident from core and trapped sediments.  Therefore, the Meadow varve is typically a simple couplet composed of an initial coarse silt layer and clay cap with few subannual laminae.  Hence the signal from Meadow Lake is at best, an indication of nival melt intensity for that watershed.  
PARAGRAPH_XXO By contrast, in Summit Lake the presence or absence of a discharge event within the varve depends on the intensity and duration of both nival and glacial peak discharges, as well as late season river discharge events.  A Summit Lake varve typically consists of multiple graded units ranging from coarse to fine silt and clay.  The thin clay cap is frequently interrupted by a unit of coarse sediment likely deposited during major autumn rainstorms.
PARAGRAPH_XXO In summary, this study demonstrates that a watershed can record discernable sedimentary events related to three different types of runoff.  It is possible to compare the sensitivity to nival melt intensity between the two lakes through comparison of runoff units preserved in the respective varves.  Regional river discharge, air temperature and precipitation records can further decipher the series of subannual events preserved in varves from Summit Lake.  

REFERENCE_XXO Hardy, D. R., Bradley, R. S., and Zolitschka, B., 1996. The climatic signal in varved sediments from Lake C2, northern Ellesmere Island, Canada: Journal of Paleolimnology, v. 16, 227-238.
REFERENCE_XXO Lamoureux, S. F., 2000. Five centuries of interannual sediment yield and rainfall-induced erosion in the Canadian High Arctic recorded in lacustrine varves, Water Resources Research: v. 36, p. 309-318

INSERT_PAGE_BREAK_HERE
TITLE_XXO LGM DISPERSAL TRAINS OF THE WESTERN INNUITIAN ICE SHEET

AUTHORS_XXO COULTHARD, ROY (1); England, John (2); Atkinson, Nigel (3)

AUTHOR_1_XXO (1) Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada, now at INSTAAR; Roy.Coulthard@Colorado.EDU
AUTHOR_2_XXO (2) Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada; John.England@ualberta.ca
AUTHOR_3_XXO (3) Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada; na1@ualberta.ca

PARAGRAPH_1_XXO The distribution of glacially transported erratics in the westernmost Canadian Arctic Archipelago was mapped on western Axel Heiberg and Meighen islands, Nunavut. On Axel Heiberg Island, boulders up to eight metres in length were observed above marine limit. The provenance of sandstone boulders is attributed to the Isachsen Formation that outcrops at the mountain front to the east. The association of these boulders with till and radiocarbon-dated deglacial (Holocene) marine sediment suggests that they were deposited during the Last Glacial Maximum (LGM). Isachsen Fm. boulders traced westward from the interior mountains of Axel Heiberg Island suggest a vigorous westward glacier flow during the LGM. 
PARAGRAPH_XXO Forty km to the west of Axel Heiberg Island, on the continental shelf, Meighen Island is capped by unconsolidated sand of the Neogene Beaufort Formation (Thorsteinsson, 1961). Faceted and striated boulders, interpreted to be till, overlie the Beaufort Fm. across the island. The till was composed of sandstone, diabase, quartzite and pink and red granites, all foreign to Meighen Island. Granite erratics were ubiquitous on the southwestern two-thirds of the island, but were absent on the northeastern third where diabase erratics were dominant. Granite erratics have not been observed on southern or western Axel Heiberg Island, nor on the small, basaltic Fay Islands within Sverdrup Channel, between Axel Heiberg and Meighen islands. The absence of granite on northeastern Meighen Island and the Fay Islands suggests that most of a trunk glacier in Sverdrup Channel was fed directly from Axel Heiberg Island ice which displaced regional granite-bearing ice farther to the west. Hand sample analysis of Meighen Island granite erratics suggests they are compositionally similar to Shield bedrock on southeast Ellesmere Island (Frisch, 1988), as well as to granite erratics on the sedimentary terrain of southern Ellesmere Island, (O Cofaigh et al., 2000) and granite erratics from Amund Ringnes Island (Atkinson, 2001). Consequently, a common Ellesmere Island provenance is suggested for granite erratics extending northwestward to Meighen Island. 
PARAGRAPH_XXO This study provides further support for the Innuitian Ice Sheet (IIS) model of Blake (1970). We support the conclusion of Atkinson (2001) that a northwestward-flowing trunk glacier (or ice stream), fed by convergent Ellesmere Island and Axel Heiberg Island ice, occupied Massey Sound (west of Axel Heiberg Island) during the LGM. Northwestward-flowing ice from the axis of the IIS in the central Arctic (Dyke 1999) also crossed Cornwall Island  (Lamoureux and England 2000), contributing additional ice to Massey Sound that collectively advanced across Meighen Island and adjacent channels to the continental shelf. This conclusion raises the possibility that clastic sediment may have been delivered to the Arctic Ocean Basin from the former margin of the IIS in Heinrich-like events.

REFERENCE_XXO Atkinson, N., 2001. The Quaternary glacial history of the Ringnes Islands, Nunavut, Canada. in: 31st International Arctic Workshop, Program with Abstracts, 2001. Department of Geosciences, University of Massachusetts, 116pp.
REFERENCE_XXO Blake, W., Jr., 1970. Studies of glacial history in arctic Canada. I. Pumice, radiocarbon dates, and differential postglacial uplift in the eastern Queen Elizabeth Islands. Canadian Journal of Earth Sciences, 7: 634-664
REFERENCE_XXO Dyke, A.S., 1999. Last Glacial Maximum and deglaciation of Devon Island, Arctic Canada: support for an Innuitian Ice Sheet. Quaternary Science Reviews, 18: 393-420
REFERENCE_XXO Frisch, T., 1988. Reconnaissance geology of the Precambrian Shield of Ellesmere, Devon and Coburg Islands, Canadian Arctic Archipelago. Geological Survey of Canada Memoir 409. 102pp.
REFERENCE_XXO Lamoureux, S.F. and England, J.H., 2000. Late Wisconsinan glaciation of the central sector of the Canadian High Arctic. Quaternary Research, 54: 182-188
REFERENCE_XXO O Cofaigh, C., England, J. and Zreda, M., 2000. Late Wisconsinan glaciation of southern Eureka Sound: evidence for extensive Innuitian ice in the Canadian High Arctic during the Last Glacial Maximum. Quaternary Science Reviews, 19: 1319-1341
REFERENCE_XXO Thorsteinsson, R. 1961. The history and geology of Meighen Island, Arctic Archipelago. Geological Survey of Canada Bulletin 75. 20pp.

INSERT_PAGE_BREAK_HERE
TITLE_XXO BIOSEQUENCES, THE PALEO-BIOTIC RESPONCE TO CLIMATE CHANGE IN THE QUATERNARY DEPOSITS OF THE CANADIAN BEAUFORT SHELF.

AUTHORS_XXO Davies, Ed (1); BLASCO, STEVE (2)

AUTHOR_1_XXO (1) Branta Biostratigraphy Ltd.; daviese@cadvision.com
AUTHOR_2_XXO (2) Geological Survey of Canada; sblasco@nrcan.gc.ca

PARAGRAPH_1_XXO 
PARAGRAPH_XXO The Quaternary section of the Canadian Beaufort Shelf consists of a thick sediment wedge that accumulated in the subsiding Tertiary age Beaufort-Mackenzie sedimentary basin (Blasco et al, 1990).  In 1988 Gulf Canada Resources Limited completed a 500m deep borehole in 32m of water on the central Canadian Beaufort Shelf near the Quaternary depocentre of the Beaufort-Mackenzie sedimentary basin.  The Pleistocene to Holocene core samples from the Gulf Amauligak 3F-24 deep borehole and a series of shallow subseabed boreholes located on the inner shelf of the Beaufort Sea have been analyzed to model deep core biostratigraphy. Recovered core samples were analyzed for palynology, botanical macrofossils, arthropods and micropaleontology.
PARAGRAPH_XXO   
PARAGRAPH_XXO Palynological distributions exhibit strong cyclicity in the marine dinoflagellates, euryhaline algae, terrestrial pollen and spores, organic walled faunal tests and reworked palynomorphs.  The distributions of the aquatic palynomorphs allows for the recognition of fluvial, transitional to nearshore depositional environments. Determination of the paleovegetation can be made utilizing the association of the terrestrial derived pollen and spores.  Botanical macrofossil distributions from the Amauligak 3F-24 core samples exhibit zones of increased abundance downcore with scattered occurrences between zones.  These macrofossil assemblages are similar in basic composition comprising predominately spruce needles and sedge seeds, boreal and tundra shrubs and herbs along with diverse moss fragments comprising both arctic and boreal forms.  Arthropod segments are common comprising a diverse fauna similar to that of the Mackenzie Delta today. Samples analyzed for micropaleontology were often barren, however, abundant low diversity benthic elphidioid foraminiferal and ostracodes assemblage define marine intervals while euryhaline cyprid ostracode assemblages identify transitional environments.
PARAGRAPH_XXO Biostratigraphically defined depositional environments range from lacustrine or fluvial delta top to middle neritic delta front but are predominately estuarine/delta top to shoreface.  The paleovegetation consists of boreal forest to high arctic tundra with forest-tundra or littoral tundra being the most prominent.  The expanding boreal forest and changing tundra biomes coupled with sea level changes and variations in freshwater influx result in the generation of sequential palynological assemblages, which reflect the stadial-interstadial and glacial-interglacial cyclicity in the Mackenzie Delta/ Beaufort Sea.  This paleo-biome succession can be described and interpreted as a series of biosequences where a biosequence is defined as:
PARAGRAPH_XXO The stratigraphic interval delimited by the development and deterioration of a fossil biome or paleobiome represented by a series of fossil assemblages in succession.
PARAGRAPH_XXO  The concept of a biosequence allows for the construction of a comprehensive paleontological facies model which facilitates the description of the cyclical succession of fossil assemblages. The preliminary ideas were presented by Davies & Bujak (1987) from studies on the Plio-Pleistocene of northern Gulf of Mexico. Palynological cyclicity reflected the changing floral development responding to glacial-interglacial climatic cycles of North America.  This technique has been adapted and applied to the Quaternary strata of the Canadian Beaufort Shelf.
PARAGRAPH_XXO  
PARAGRAPH_XXO The idealized biosequence (figures 1 and 2) reflecting a complete development and collapse of a paleo-biome has been constructed in order to express the changes in floral and faunal development and climate (warmth and precipitation) during the time of deposition. The six main interdependent driving forces for this cyclicity are interpreted to be: glacial advancement (terrestrial niche destruction), sediment influx (turbidity), freshwater influx (including salinity and nutrients), temperature (both air and sea), precipitation and isostatic/eustatic sea-level changes (the development of marine niches).  The succession of marine and freshwater fossil communities and of terrestrial floral communities follows through an idealized biosequence divided into four phases and ten assemblages discerned primarily by the varying fossil diversities and abundances. The resulting succession of assemblages produces a biosequence log reflecting a glacial-interglacial-glacial cycle. The complete, idealized palynological biosequence proceeds upward from left to right, with the next cycle subsequently starting from the far left in figure 1.
PARAGRAPH_XXO  
PARAGRAPH_XXO In the section penetrated by the Beaufort/Mackenzie boreholes seven biosequences comprising a total of 19 subsequences can be defined.  These correspond closely to described coarse and fine-grained sedimentological units. However, the boundaries between the biosequences often occur within the bottom of the coarse-grained units rather than at the boundary between the coarse-grained and fine-grained units. The biosequences can be further grouped into three larger trends which correspond to major periods of sediment accumulation and development of marine conditions.
PARAGRAPH_XXO The integration of a biosequence stratigraphy with sedimentological and geochemical data will result in a much clearer understanding of the depositional history of ice-bearing Quaternary sediments of the Beaufort Shelf. 

REFERENCE_XXO Blasco, S.M., Fortin, G., Hill, P.R., O'Connor, M.J. and Brigham-Grette, J., 1990. The late Neogene and Quaternary stratigraphy of the Canadian Beaufort continental shelf, in The Arctic Ocean Region, The Geology of North America, vol L, ed. A. Grantz, L. Johnson and J. F. Sweeney, p 491-502.
REFERENCE_XXO Davies, E.H.  and Bujak, J.P., 1987. Petroleum exploration and the application of palynological assemblage successions in the Flexure Trend, Gulf of Mexico. In Innovative Biostratigraphic Approaches to Sequence Analysis: New Exploration Opportunities. Eighth Annual Research Conference, Gulf Coast Section, Society of Economic Paleontologists and Mineralogists Foundation, Houston, December 6-9, 1987, pp. 47-51.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/67-1.jpg

CAPTION_XXO Fig 1.  Idealized Biosequence BIOME Succession.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/67-2.jpg

CAPTION_XXO Fig 2.  Biosequences and Sedimentary Cycles.

INSERT_PAGE_BREAK_HERE
TITLE_XXO IMPACTS OF CLIMATE CHANGE ON NITROGEN FIXING MICROBIAL COMMUNITIES IN THE CANADIAN HIGH ARCTIC

AUTHORS_XXO DESLIPPE, JULIE R. (1); Egger, Keith N. (2)

AUTHOR_1_XXO (1) University of Northern British Columbia; deslippj@unbc.ca
AUTHOR_2_XXO (2) University of Northern British Columbia; egger@unbc.ca

PARAGRAPH_1_XXO Many terrestrial arctic ecosystems are strongly nitrogen limited. Nitrogen-fixing bacteria (diazotrophs) are important regulators for plant productivity at these sites. Global warming may alter selective pressure on bacterial communities causing changes in bacterial diversity and community structure and resulting in sustained alteration of the nitrogen budget for plants. The objectives of my research are to examine the diversity and community structure of diazotrophic communities under conditions of simulated climate change in the Canadian high arctic and to examine nitrogen inputs from the communities. A nested PCR protocol will be used to amplify nifH gene sequences from bulk DNA extracted from soils of warmed and fertilised plots from a mesic site at Alexandra Fiord, Ellesmere Island, Nunavut. Terminal restriction fragment length polymorphisms (T-RFLPs) will be used to analyse the diversity of nifH gene sequences from each treatment. Concurrently, measurements of nitrogen fixation will be made by the acetylene reduction and the  15N methods. NifH gene diversity will be related to the rate of nitrogen fixation. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO ARCHEOLOGY OF ALASKA GLACIERS AND SNOW FIELDS

AUTHORS_XXO DIXON, E. JAMES (1); Manley, William F. (2)

AUTHOR_1_XXO (1) University Museum and INSTAAR; jdixon@colorado.edu
AUTHOR_2_XXO (2) INSTAAR; William Manley <William.Manley@colorado.edu>

PARAGRAPH_1_XXO 
PARAGRAPH_XXO Approximately 10% of the earth's land surface is covered by ice.  Global warming is rapidly melting ice and exposing rare archeological remains.  These sites are important to understanding the role of high latitude and high altitude environments in human adaptation and cultural development.  GIS modeling is used to identify areas in Alaska's Wrangell St. Elias National Park exhibiting high potential for the preservation and discovery of frozen archeological remains.  Areas holding the highest potential for archeological site discovery are: 1) ice-covered passes used as transportation corridors, and 2) glaciers and areas of persistent snow cover used by animals that attracted human predators.  
PARAGRAPH_XXO A preliminary GIS model was field tested by aerial reconnaissance and pedestrian survey.  Thirty-two sites at which archaeological and/or paleontological specimens were found.  Historic artifacts included horse hoof rinds and associated horseshoe nails on the Nabesna glacier.  This unusual discovery indicated that a horse had been shod on the glacier in historic times.  A can fragment and a piece of culturally cut wood were recovered on the ice near the terminus of the Chisana glacier.  These discoveries were all made below the ELA’s of these large glaciers at an elevation of approximately 3400’ (~1036m).  The recovered artifacts demonstrate the presence of exceptionally well-preserved archeological remains that were successfully predicted by the GIS model for glaciers historically documented as trails and passes over mountain ranges. A prehistoic antler projectile point possibly associated with a punctured large mammal scapula was recovered near a snowfield in the vicinity of Tanada Peak at approximately 5800’ (~1767m).  In addition to the archaeological specimens, numerous paleontological specimens including well preserved rodents were encountered during the survey.  Discoveries include the rremains of Dall sheep, caribou, carnivores, the frozen remains of medium sized mammals, micotines, birds, mammalian hair, fecal material, and even a complete perfectly preserved fish.
PARAGRAPH_XXO Field survey determined that site potential values from the model were higher for the documented sites than for the study area in general, suggesting that the a priori model meaningfully identified areas of archeological potential.  This also suggests the model is based on fundamentally sound criteria, but requires refinement.  Several important observations indicate where and how it should be refined.  For example, six sites fell outside predictions. Subsequent analysis of these six sites demonstrate that all were located on relatively small perennial snow patches observed during aerial reconnaissance, but not predicted by the model because cartographic, photographic, and satellite imagery lacked the resolution to detect these small features. These problems can be corrected by incorporating multispectral remote sensing data and high quality landsat images for northern Wrangell’s in the GIS model.
PARAGRAPH_XXO Global warming presents an unprecedented opportunity to identify ice fields and similar contexts holding the highest potential for the exposure and discovery of frozen archeological remains.  Preliminary research demonstrates that these locales can be detected by GIS modeling to identifying glaciers and perennial ice patches most probably used by humans.  These features can be documented through the analysis of social/cultural, biological, remote sensing, and geologic data.  Glaciers and ice patches are melting at an unprecedented rate and it is anticipated that will increasingly older and significant artifacts, paleontological and other materials will be exposed on thawing surfaces.  This research will provide a valuable tool to focus limited resources on areas exhibiting the greatest potential for archeological and paleontological discovery and recovery.  

INSERT_PAGE_BREAK_HERE
TITLE_XXO MULTIPROXY DATA ACROSS THE LAST TERMINATION I FROM THE NORTH ATLANTIC: OCEAN CIRCULATION AND OCEAN-ICE SHEET INTERACTION

AUTHORS_XXO DOKKEN, TROND M.

AUTHOR_1_XXO Bjerknes Centre for Climate Research; trond.dokken@bjerknes.uib.no

PARAGRAPH_1_XXO Sediment cores from the Nordic Seas/North Atlantic have been investigated in order to reconstruct the phase relationship in different oceanic proxies during rapid transitions in the interval from the last glacial maximum to the Holocene. During the last termination it is possible to identify several modes of circulation that may have significant positive feedback on climate. 
PARAGRAPH_XXO In the context of the recent discussion whether the Southern and Northern Hemispheres were out of phase during major re-organisations of climate, it is of major importance to evaluate the phase relationship between changes observed in processes in surface- and deep water and ice sheet dynamics within the Hemispheres. What we observe from the Northern Hemisphere (North Atlantic/Nordic Seas) is that different proxies reflecting changes in deep-water overturning, strength of deep- and surface water flow, surface water cooling and warming, surface water freshening and ice sheet activity, often are out of phase within the same region. These observations show that different processes may well be reflecting responses to different mechanisms. It is therefore important that inter-hemispheric correlation is evaluated in the context of lead and lag within one region.

INSERT_PAGE_BREAK_HERE
TITLE_XXO USGS YUKON RIVER STUDIES

AUTHORS_XXO DORNBLASER, MARK (1); Striegl, Rob (2); Hooper, Richard (3); Aiken, George (4); Eberl, Dennis (5); Krabbenhoft, David (6); Schuster, Paul (7)

AUTHOR_1_XXO (1) USGS; mmdornbl@usgs.gov
AUTHOR_2_XXO (2) USGS; rstriegl@usgs.gov
AUTHOR_3_XXO (3) USGS; rphooper@usgs.gov
AUTHOR_4_XXO (4) USGS; graiken@usgs.gov
AUTHOR_5_XXO (5) USGS; ddeberl@usgs.gov
AUTHOR_6_XXO (6) USGS; dpkrabbe@usgs.gov
AUTHOR_7_XXO (7) USGS; pschuste@usgs.gov

PARAGRAPH_1_XXO Study Objectives:  The Yukon River basin covers 330,000 square miles in northwestern Canada and central Alaska, an area greater than Texas (Figure 1).  It is one of the largest and most diverse ecosystems in North America, and is of prime importance to the ecology of the Bering Sea, contributing most of its freshwater runoff, sediment load, and dissolved solutes.  
PARAGRAPH_XXO      
PARAGRAPH_XXO The Yukon River basin is changing.  Air temperature records between 1961-1990 show a warming trend of about 0.75 degrees C per decade at latitudes where the Yukon River is located.  Continued warming will affect permafrost distribution, glacial runoff, and biogeochemical fluxes within and from the basin.   The exact effects are unclear.  The USGS National Stream Quality Accounting Network (NASQAN) is developing a baseline characterization of water quality conditions in the Yukon Basin that will serve as a benchmark for future studies of the river.  In addition, USGS is conducting a variety of process studies in the basin, investigating such topics as the production and utilization of dissolved organic carbon in headwater areas, Hg methylation, water-atmosphere exchange of greenhouse gases, and sediment chemistry. 
PARAGRAPH_XXO Study Approach:  NASQAN is performing fixed station sampling at five sites during 2001-2005 (Figure 2) to estimate annual mass fluxes.  Scientists will also conduct intensive boat-based synoptic samplings to create a broader spatial characterization of the river and it's sub-basins.  In addition, lake sediment cores will be analyzed for trends and seasonal input of atmospherically transported contaminants.
PARAGRAPH_XXO Fixed Site Network:  The five fixed sites will be sampled for a variety of organic and inorganic constituents over a five year period to establish a baseline database.  Each year, these sites will be sampled approximately seven times, including one under-ice measurement.  Mass fluxes calculated for the fixed sites will be used to identify source areas of contaminants, and to estimate delivery of these contaminants to the Bering Sea.  
PARAGRAPH_XXO Synoptic Sampling:  Scientists will conduct intensive boat-based sampling of the Yukon River twice per year, once near peak flow conditions in early June and once near base flow conditions in August/September.  The entire Yukon River will be sampled by this method over a three year period.  In 2002, sampling will occur through Yukon Flats between Eagle and Stevens Village, Alaska.  In 2003, between Stevens Village and Pilot Station.  And in 2004, between Whitehorse, Canada, and Eagle, Alaska.  The synoptic sampling will increase the interpretability of the flux measurements, and will provide an alternate data set that may be a more sensitive indicator of change. 

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/38-1.jpg

CAPTION_XXO Fig 1.  Figure 1: Location of the Yukon River Basin in Alaska and Canada

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/38-2.jpg

CAPTION_XXO Fig 2.  Figure 2: Locations of fixed station sites in the Yukon River Basin

INSERT_PAGE_BREAK_HERE
TITLE_XXO QUANTIFYING THE LINK BETWEEN CLIMATE AND FIRE IN ALASKA

AUTHORS_XXO DUFFY, PAUL A. (1); Rupp, Scott (2); Mann, Daniel H. (3); Graham, Jonathan M. (4)

AUTHOR_1_XXO (1) University of Alaska Fairbanks; pduffy@neptuneandco.com
AUTHOR_2_XXO (2) University of Alaska Fairbanks; scott.rupp@uaf.edu
AUTHOR_3_XXO (3) University of Alaska Fairbanks; dmann@mosquitonet.com
AUTHOR_4_XXO (4) University of Montana Missoula; JGraham@mso.umt.edu

PARAGRAPH_1_XXO Increased awareness of the role disturbance mechanisms play in shaping the spatio-temporal distribution and functional characteristics of vegetation has identified a need to characterize transient ecosystem dynamics. Transient dynamics are the short-term interactions resulting from feedbacks that occur between climate, vegetation, and disturbance factors in ecosystems during rapid climatic changes. The development of landscape-level vegetation models requires the integration of transient ecosystem dynamics in a regional and global framework. Informing these Dynamic Global Vegetation Models (DGVMs) with respect to disturbance processes operating at the landscape-scale is a critical step in model development. This study quantifies the link between climate and fire in the boreal forest of Alaska. Specifically, we developed a statistical model that regresses the natural logarithm of the total annual hectares burned on average monthly temperature, precipitation, and atmospheric teleconnection indices. Climate changes occurring at multiple temporal scales are coupled and the importance of the scale considered depends on the response of interest. Model results support the contention that atmospheric teleconnections operating on decadal to sub-decadal time scales influence fire regime through impacts on monthly climate in Alaska. The statistical model identifies five climatological variables that collectively explain over 65% of the variability in the natural logarithm of hectares burned per year in Alaska.  These variables are linked to fuel moisture dynamics, and synoptic weather events that drive fire ignition and spread. Quantification of the link between climate and fire in Alaska is not only essential for accurate simulation of disturbance processes operating at the landscape-scale but also a valuable tool for planning fire management activities.

INSERT_PAGE_BREAK_HERE
TITLE_XXO STATUS: PRELIMINARY DEGLACIATION MAPS FOR NORTH AMERICA

AUTHORS_XXO DYKE, ARTHUR S. (1); Moore, Andrew (2); Robertson, Louis (3)

AUTHOR_1_XXO (1) Terrain Sciences Division, Geological Survey of Canada; adyke@nrcan.gc.ca
AUTHOR_2_XXO (2) Terrain Sciences Division, Geological Survey of Canada
AUTHOR_3_XXO (3) Terrain Sciences Division, Geological Survey of Canada

PARAGRAPH_1_XXO At the annual meeting of the Canadian Geophysical Union in May, 2001, a workshop decided that it was necessary to update the North American deglaciation map series in support of planned high-resolution uplift modelling. As a first step, we have updated the Dyke and Prest (1987) map series, incorporating the most significant changes known to us and added the 15, 16, and 17 ka time slices. The next steps are to increase the resolution of the map series to 500 year intervals in the radiocarbon time scale and then proceed to 500 year intervals in the calendar time scale.
PARAGRAPH_XXO Unlike the previous maps, the new maps are fully digital and all "accepted" radiocarbon dates constraining ice and glacial lake fronts are plotted from a database. Key varve dates are also included, converted to radiocarbon time. Currently, the database contains about 3700 accepted dates. Marine shell dates, a major component of the database, are adjusted by a set of regional reservoir corrections that range from 800 years in the Pacific Ocean and Champlain Sea to 450 years in the outer Gulf of St Lawrence (Dyke et al., in prep.). A parallel database of about 600 "retired" radiocarbon dates, many of which were used to constrain previous ice margins, is also available.
PARAGRAPH_XXO In comparison to the previous maps, deglaciation is delayed on average by about 1000 years.
PARAGRAPH_XXO Viewers of this poster are encouraged to submit comments and corrections to the first author (adyke@nrcan.gc.ca).

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE DEVELOPMENT OF FISHING IN THE NORTHWEST OF ICELAND

AUTHORS_XXO EDVARDSSON, RAGNAR

AUTHOR_1_XXO The City University of New York, Graduate Center; ragnar@nyc.rr.com

PARAGRAPH_1_XXO The environment has always played an important part in Icelandic society from the settlement of the country in the 9th century. The history of Iceland is well documented and the historic documents frequently refer to the climate and other natural phenomenons that dramatically affected Icelandic society. 
PARAGRAPH_XXO Iceland’s vulnerability to climate impacts in the past, and potentially in the future, is due in large measure to the variability of the climate. This results principally from the country’s geographical location at a point where contrasting air and ocean currents meet. The sea ice which drifts to the coasts of Iceland on the East Greenland current has also been of great importance as it has had a number of both direct and indirect climate impacts.
PARAGRAPH_XXO The effects of climatic changes in Iceland have long been known but poorly understood. It is only recently that scholars have begun paying attention to this important factor in the development of Icelandic society.
PARAGRAPH_XXO Archaeological research in Iceland in the past 10 years has shown that any change in the dynamic society is a result of a critical set of interactions between both cultural and environmental factors. These interactions have a strong spatial pattern, a development through time and leave a physical legacy in the environmental record.
PARAGRAPH_XXO The research into the development of fishing in the Northwest of Iceland focuses on understanding the fishing industry during the period from the settlement of the country to 1700. The project uses both archaeological and historical data in its approach and the goal is to try to detect social and environmental factors that caused changes in the fishing industry. The fishing industry seems to have played a much more important role in the economy of the society until 1200 than previously thought. 
PARAGRAPH_XXO The Northwest contains multiple fishing stations of different size and date, many of which have associated deep bone middens. A major focus of this  project will be to systematically compare evidence for changing balance of marine/terrestrial resources through time in this area in light of differential impacts of climate change and erosion on terrestrial ecosystems and of sea ice and current fluctuations on marine ecosystems.

INSERT_PAGE_BREAK_HERE
TITLE_XXO LANDSCAPES CIRCUM-LANDNóM: VIKING SETTLEMENT IN THE NORTH ATLANTIC AND ITS HUMAN AND ECOLOGICAL CONSEQUENCES: A MAJOR NEW RESEARCH PROGRAMME

AUTHORS_XXO EDWARDS, KEVIN J. (1); McGovern, Thomas H. (2); Buckland , Paul  C. (3); Dugmore , Andrew J. (4); Simpson , Ian  A. (5); Sveinbjarnardœttir , GuÂrÁn (6)

AUTHOR_1_XXO (1) Department of Geography & Environment, University of Aberdeen, UK; kevin.edwards@abdn.ac.uk
AUTHOR_2_XXO (2) Department of Anthropology, Hunter College, City University New York, USA; nabo@voicenet.com
AUTHOR_3_XXO (3) Department of Archaeology & Prehistory, University of Sheffield, UK; p.buckland@sheffield.ac.uk
AUTHOR_4_XXO (4) Department of Geography, University of Edinburgh, UK; ajd@geo.ed.ac.uk
AUTHOR_5_XXO (5) Department of Environmental Science, University of Stirling, UK; ias1@stir.ac.uk
AUTHOR_6_XXO (6) Institute of Archaeology, University College London, UK; gudrun@sveinbjarnar.freeserve.co.uk

PARAGRAPH_1_XXO Substantial funding for an interdisciplinary research programme has been made available by a UK-based charity, the Leverhulme Trust. The opportunity is taken here to outline the scope of a programme which is scheduled to last 5 years and will involve research collaboration across nine countries.
PARAGRAPH_XXO The grant will fund an investigation into the human and ecological consequences of Norse settlement in the North Atlantic region. The study will provide a high resolution and comprehensive assessment of what happens environmentally and socially when a group of people colonise 'pristine' landscapes. The project aims to examine the period from ca AD 400 to Landnám (to establish environmental baselines before human settlement), through Landnám (the phase of colonization) and on to ca AD 1500. This interval will permit an assessment of the inter-relationships between human and natural forces upon natural and modified ecosystems in the Faroes, Iceland and Greenland.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/7-1.gif

CAPTION_XXO Fig 1.  The North Atlantic area showing initial research locations in the Faroe Islands, Iceland and Greenland

INSERT_PAGE_BREAK_HERE
TITLE_XXO NORTH ICELANDIC SHELF SEDIMENTS: HOLOCENE AND LATEGLACIAL RECORD OF OCEANOGRAPHIC EVENTS

AUTHORS_XXO Eiriksson, Jon (1); Knudsen, Karen Luise (2); RYTTER, FRANK (3)

AUTHOR_1_XXO (1) Science Institute, University of Iceland, IS-101 Reykjavýk, Iceland; jeir@rhi.hi.is
AUTHOR_2_XXO (2) Department of Earth Science, University of Aarhus, DK-8000 Aarhus C, Denmark
AUTHOR_3_XXO (3) Department of Earth Science, University of Aarhus, DK-8000 Aarhus C, Denmark; frank.rytter@geo.au.dk

PARAGRAPH_1_XXO Modern atmospheric and oceanographic processes in the Iceland region of the North Atlantic are characterized by strong gradients separating the Arctic and Atlantic realms. Geologically, the north Icelandic shelf is partly distinguished by the Tjörnes Fracture Zone featuring numerous active basins in a mud dominated shelf environment. Lateglacial and Holocene high-resolution sedimentary records from this area have been studied with tephrochronology as the main tool for correlation and for exact timing of palaeoceanographic events in the area.
PARAGRAPH_XXO Several larger palaeoceanographic shifts occurred in the area during the Lateglacial and the early Holocene. Benthic foraminiferal assemblages indicate a strong influence of Atlantic water masses (Alabaminella weddellensis, Cassidulina neoteretis, Miliolida) on the sea floor. Similar, but weaker, environmental signals are repeated during part of the Younger Dryas around the level of the Vedde tephra marker. An oceanographic cooling started at the beginning of both the Bölling-Alleröd and the Preboreal (Islandiella norcrossi, Nonionellina labradorica, Elphidium excavatum, Cassidulina reniforme), indicating an antiphase relationship between the climate signals in this area and those of the eastern North Atlantic. Foraminiferal assemblages of Holocene records demonstrate that relatively warm conditions prevailed between 10,000 and 6,000 cal. BP (the Holocene Climatic Optimum), interrupted by a cooling of the sea surface of about 3&#61616;C at around 8,200 cal. BP.
PARAGRAPH_XXO Data from three new IMAGES piston cores recovered in the shelf area show how tephra markers can be used for the first evaluation of a chronology and correlation of the cores. The correlation is extended with lithological logs and with magnetic susceptibility records. Two different possible age models, one based on 14C dates combined with tephra markers and one based on tephra markers alone, are presented in context with the problem of different marine reservoir ages of the water masses in the area.
PARAGRAPH_XXO A detailed multidisciplinary study of a late Holocene record from the area demonstrates that marked variations in the distribution of water masses occurred repeatedly through the last 4500 cal. years. Of special interest is the exact timing of a marked drop in sea-surface temperature in the area, indicated by ice rafting debris concentration, to about 50 years before the Hekla 3 eruption, which occurred at 2980 cal. BP. This appears to predate most records of a general cooling event in NW Europe by a couple of centuries. Also the Medieval Warm Period and the Little Ice Age are expressed in the assemblages.
PARAGRAPH_XXO The present study emphasizes the importance of combining age models based on AMS 14C datings with tephrochronological studies,  in order to obtain a better understanding of marine reservoir ages of the different water masses both in space and in time. This applies not only to stadial versus interstadial intervals with major shifts in the oceanic systems, but also to the Holocene time period, where variation in the influence of different water masses causes a change in reservoir age through time as well. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE ND, SR AND PB ISOTOPIC COMPOSITIONS OF ICE PROXIMAL SEDIMENTS: IMPLICATIONS FOR ICE SHEET DYNAMICS AND THE SOURCES OF QUATERNARY IRD IN THE NORTH ATLANTIC

AUTHORS_XXO FARMER, G. LANG (1); Barber, Donald C. (2); Andrews, John T. (3)

AUTHOR_1_XXO (1) University of Colorado; farmer@cires.colorado.edu
AUTHOR_2_XXO (2) Bryn Mawr College; dbarber@brynmawr.edu
AUTHOR_3_XXO (3) University of Colorado; andrewsj@spot.colorado.edu

PARAGRAPH_1_XXO The Nd, Sr and Pb isotopic compositions of Quaternary, ice-proximal sediments from around the northern North Atlantic have been determined to fingerprint the isotopic characteristics of potential sources of ice-rafted detritus (IRD) in this region, as well as to study the dynamics of the various Quaternary, circum-northern Atlantic ice sheets.  Targeted for study were sediments deposited adjacent to the Laurentide (Baffin Bay, western Hudson Strait, Cartwright Saddle and the Gulf of St. Lawrence), Greenland and Iceland (Denmark Strait and vicinity), and Fennoscandian (Bear Island fan, mid-Norwegian continental shelf) ice sheets.  In each area we obtained isotopic data primarily from the <63 um size fraction, but in some cases the >63 um size fraction was analyzed as well.
PARAGRAPH_XXO From the eastern margin of the Laurentide ice sheet (LIS), <63um sediments from Baffin Bay have low eNd (-23.1 to –27.2; Fig. 1), high 87Sr/86Sr (0.7259 to 0.7356), and variable Pb isotopic compositions (206Pb/204Pb=16.82 to 17.73).  Those samples from the central and southern Baffin Bay have lower eNd, older Nd model ages (~2.4 b.y.) and higher 87Sr/86Sr.  The latter also plot along a ~2.0 b.y. secondary Pb errorchron, whereas samples from northern Baffin Bay plot above this line. Fine-grained glacial sediments from western Hudson Strait have uniformly low eNd (-28.1 to –28.9), 87Sr/86Sr=0.720 to 0.726, and variable Pb isotopic composition that plot along the same ~2.0 b.y. errorchron defined by the Baffin Bay samples. At Cartwright Saddle, offshore of northern Labrador, glacial sediments also have low eNd (-21 to –22.5; TDM=2.0 to 2.2 b.y.) but lower 87Sr/86Sr (0.7159-0.7169) than glacial detritus further north.  In contrast, both coarse- and fine- grained sediment from the Gulf of St. Lawrence (GSL) have significantly higher eNd values (-11.9 to –15.1; TDM=1.5 to 1.8 b.y.), and generally lower 87Sr/86Sr ratios (0.7171 to 0.7227) than glacial sediment deposited at higher latitudes.  The coarse GSL sediments also define a 450 m.y. Sr errorchron.  These data reveal that the isotopic compositions of ice-proximal marine sediment offshore eastern Canada reflect the isotopic compositions of adjacent Precambrian crustal terranes and so illustrate that sediment derived from different portions of the eastern LIS, including the Hudson Strait and GSL ice streams, are isotopically distinguishable.
PARAGRAPH_XXO Sediments from the Bear Island fan in the Norwegian Sea have Nd, Sr, and Pb isotopic compositions that are essentially indistinguishable from those found in the GSL (Fig. 1).  Sediments from the mid-Norway continental shelf have isotopic compositions similar to those in the GSL and Bear Island fan, but have slightly lower eNd (~-15, TDM~1.8 b.y.) and more radiogenic Pb and Sr.  Glacial sediments deposited off western Iceland, in contrast, have high (eNd =5.7 to 6.2), low 87Sr/86Sr (0.7038 to 0.7050) and Pb isotopic compositions that plot to the right of the geochron close to the Northern Hemisphere Reference Line.  In contrast, on the east Greenland continental slope, glacial sediment has variable isotopic compositions, with eNd values ranging from +4 to –2.5 and 87Sr/86Sr from 0.7040 to 0.7085.  
PARAGRAPH_XXO Overall, our data confirm that there are significant temporal and spatial variations in the isotopic compositions of ice-proximal sediments throughout the circum Northern Atlantic.  Radiogenic isotopic data from such sediments should therefore provide an important proxy record of Quaternary ice sheet dynamics and aid in better identifying the sources North Atlantic IRD.  For example, previous studies have suggested that the relatively high eNd values of “atypical” H3 ice-rafted detritus (IRD) in the North Atlantic was derived from the Fennoscandian ice sheet (Snoeckx al., 1999).  While a possibility, our data reveal that, on isotopic grounds, ice emanating from the Gulf of St. Lawrence is an equally plausible source for this detritus.  A source for high eNd detritus in the southern Laurentide ice sheet removes the need for a European component to the detritus, and opens the possibility that most of the detritus in the IRD belt of the North Atlantic was ultimately derived from the Laurentide ice sheet.  As a result, the H-3 IRD in the North Atlantic may contain information regarding the timing of major surges in the north vs. southern portions of the LIS, but provides little information regarding the relative phasing of ice surges in the North American and northern European ice sheets.

REFERENCE_XXO Snoeckx, H., Grousset, F., Revel, M., and Boelaert, A., 1999: European contribution of ice-rafted sand to Heinrich layers H3 and H4. Marine Geology, 158: 197-208.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/71-1.gif

CAPTION_XXO Fig 1.  eNd vs. 147Sm/144Nd for ice-proximal sediments throughout the northern North Atlantic region.

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE HIGH-LATITUDE CARBON CYCLE: IMPLICATIONS FOR PALEOENVIRONMENTAL STUDIES

AUTHORS_XXO FINNEY, BRUCE P. (1); Brown, Tom (2)

AUTHOR_1_XXO (1) Institute of Marine Science, University of Alaska Fairbanks; finney@ims.uaf.edu
AUTHOR_2_XXO (2) Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory; tabrown@llnl.gov

PARAGRAPH_1_XXO A change in carbon cycling in arctic and subarctic regions has the potential to be an important feedback to the global climate system.  While much research has been focused on reconstructing northern high-latitude paleoclimatic change, less effort has been concerned with determining past changes in the carbon cycle in this region.  Lake sediments have the potential to provide important information on past changes in carbon cycling, as they contain information on both aquatic and watershed processes.  In some regions (i.e., the Alaskan Arctic Coastal Plain) lakes constitute a significant proportion of the surface area of the landscape.  To learn more about how lakes record information regarding carbon cycling, a transect of 51 lakes in Alaska spanning 60 – 70 degrees N was sampled in summer.  In addition, several lakes were sampled at weekly to bi-weekly periods for up to 2 years.  Lake water characteristics include temperature, pH, pCO2, DO, Chl-a and nutrients.  Lake suspended POM (primarily phytoplankton) and surface sediments were analyzed for C and N content, stable carbon and nitrogen isotope ratios, and in some cases radiocarbon content.  Similar to recent data from other regions, the surface water of most of the study lakes is supersaturated with respect to CO2 (pCO2 ranged from < 50 - ~10,000 ppm).  This implies a net transfer to lakes of respired CO2 from their watersheds.  The C-13 ratio of lake POM, which ranged from –15 to –45 o/oo, is inversely related to surface water pCO2.  The pCO2 of lake surface waters, in turn, is related to a number of factors, including basin hydrology, soil/vegetation characteristics, and lake productivity.  Radiocarbon analyses of POM (phytoplankton) revealed that non-contemporary ages (several hundred to several thousand years BP) are common.  In general, lakes with higher pCO2 had phytoplankton (lake POM) with lower fractions of radiocarbon relative to modern.  This implies that lakes may have significant reservoir effects, even in the absence of carbonate bedrock, due to input of CO2 from watershed organic matter of non-modern age.  This reservoir effect is likely to be ubiquitous in high-latitudes, and has significant implications for radiocarbon dating of lake sediments.

INSERT_PAGE_BREAK_HERE
TITLE_XXO GLACIAL AND NON-GLACIAL SEDIMENTARY PROCESSES IN BALSFJORD (NORTH NORWAY)

AUTHORS_XXO FORWICK, MATTHIAS (1); Vorren, Tore O. (2)

AUTHOR_1_XXO (1) University of Tromsoe, Department of Geology; Matthias.Forwick@stud.ibg.uit.no
AUTHOR_2_XXO (2) University of Tromsoe, Department of Geology; Tore.Vorren@ibg.uit.no

PARAGRAPH_1_XXO The objective of our study was to reconstruct the deglaciation history of Balsfjord (North Norway), as well as to investigate postglacial sedimentary processes. Balsfjord is a 46 km long and maximum 5 km wide fjord, located about 10 km south of Tromsoe. It is surrounded by up to 1500 m high mountains. The most prominent feature on the fjord floor is the "Skjevelnes moraine", an end moraine that divides the fjord into an "Outer" and "Inner Basin" that reach water depths of 190 m and 130 m, respectively.
PARAGRAPH_XXO Two piston cores and high-resolution seismic data (3.5 kHz penetration echo sounder) provide the basis for our study. Core JM98-1018-PC (10.01 m long) was recovered from the Outer Basin, whereas core JM98-1014-PC (9.96 m long) was taken from the Inner Basin. Core JM98-1018-PC was divided into 10 lithostratigraphic units. The lowermost unit comprises cyclic glacimarine sediments. These are truncated by a coherent slump that is covered with suspension fall-out. Further upcore, open marine sedimentation is interrupted by gravity flow deposits in form of one high-density turbidity current and two cohesive debris flows. Core JM98-1014-PC comprises exclusively non-glacial marine sediments and it is divided into 7 lithostratigraphic units. A debris flow deposit and suspension fall-out sediments compose the lowermost two units of the core. Further upwards, open marine sedimentation is interrupted by gravity flow deposits, in this case including two low-density turbidites.
PARAGRAPH_XXO Based on radiocarbon dates, the following chronology of Balsfjord was established. The Balsfjord glacier retreated from the Tromsoe-Lyngen moraines (Younger Dryas) prior to 10.4 14C ka BP. Between 10.4 and 9.9 14C ka BP deposition of the Skjevelnes moraine in the central part of Balsfjord occurred. After 9.9, but before 9.7 14C ka years BP, deposition of two minor end moraines took place. The transition from glacimarine to open marine environment occurred around 9.7 14C ka BP.
PARAGRAPH_XXO Three gravity flow events, deposited between c. 9.5 and 8.8 14C ka BP, were correlated between the two cores. Since these events can be correlated across the moraine, they are suggested to indicate regional avalanches. This rather high frequency of mass movements in the early postglacial period may primarily be due to tectonic activity induced by rapid isostatic uplift. The occurrence of a single gravity flow event in the Outer Basin was estimated to 8.5 14C ka BP. For the time after 8.5 14C ka BP, no avalanche activity is archived in the cores.

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE LAST DEGLACIATION IN THE DENMARK STRAIT, NORTH ATLANTIC: INDCIATIONS OF A LARGE MARINE RESERVOIR EFFECT 

AUTHORS_XXO HALD, MORTEN (1); Hagen, Sveinung  (2); Andrews, John T. (3); Jennings, Anne E. (4); Postnert, G„ran  (5)

AUTHOR_1_XXO (1) Univeristy of Tromso; Mortenh@ibg.uit.no
AUTHOR_2_XXO (2) Statoil, Norway
AUTHOR_3_XXO (3) Univ. Colorado, INSTAAR
AUTHOR_4_XXO (4) Univ. Colorado, INSTAAR
AUTHOR_5_XXO (5) Univ. Uppsala, Sweden

PARAGRAPH_1_XXO Sediment core JM96-1228/1 from the continental slope (1079 m depth) off N. Denmark Strait, has been studied in order to reconstruct the paleoceanography during the last deglaciation for this important gateway in the northern North Atlantic.  Proxy records include benthic and planktic foraminiferal ? 13C and ? 18O; foraminiferal census data and ice rafted debris (IRD).   A total of 26 AMS 14C dates have been obtained, 15 from planktic foraminifera (Neogloboquadrina pachyderma sinistral), 11 from benthic foraminifera (mixed assemblages) and one on a bivalve shell (Yoldiella intermedia). In addition, the Vedde Ash layer has been identified in the core. 
PARAGRAPH_XXO The magnetic susceptibility and rates of sediment accumulation in JM96-1228 are similar to those from an adjacent site, JM96-1229, indicating that the paleoceanographic record will not be unique to the site. By comparing the 14C dates to the Vedde Ash (10,300 14C years) and to an age model produced by correlation of the proxy data (SST-indicators and onset of the regional 15-13 14C ka meltwater spike) to the Greenland Ice Core record, the planktic 14C dates appear to be too old by 1000-1500 years and the benthic dates even older.  
PARAGRAPH_XXO The old dates may partly be explained by reworking of old carbonate due to e.g. downslope or overbank deposition by bottom currents.  However, the over all robust correlation of this proxy record to the Greenland ice cores and well-dated marine records in the Nordic seas, suggests that the old dates may reflect increased reservoir ages during the last deglaciation.  The large amount of meltwater associated with the early deglaciation probably drained like a constant flow within the East Greenland Current through the Denmark Strait.  This water may have increased the marine reservoir effect since the bicarbonate, that living organisms use to construct their tests, would be contaminated with old CO2 from the meltwater. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO ENVIRONMENT AND SOCIAL CHANGE IN WEST GREENLAND FISHERIES

AUTHORS_XXO HAMILTON, LAWRENCE C. (1); Brown, Benjamin C. (2); Rasmussen, Rasmus O. (3)

AUTHOR_1_XXO (1) University of New Hampshire; Lawrence.Hamilton@unh.edu
AUTHOR_2_XXO (2) University of New Hampshire; Cliff.Brown@unh.edu
AUTHOR_3_XXO (3) Roskilde University; ferisa@post8.tele.dk

PARAGRAPH_1_XXO Complex interactions between climatic, ecological and human 
PARAGRAPH_XXO variables occur widely in fisheries systems.  The modern history 
PARAGRAPH_XXO of west Greenland clearly illustrates this pattern.  An 
PARAGRAPH_XXO international fishery for Atlantic cod (Gadus morhua) flourished 
PARAGRAPH_XXO during a period when warm waters extended northwards along 
PARAGRAPH_XXO Greenland's SW coast, from 1920 through the 1960s.  The Irminger 
PARAGRAPH_XXO Current occasionally transported cod from seas around Iceland, 
PARAGRAPH_XXO and warmer conditions allowed local spawning off west Greenland.  
PARAGRAPH_XXO But a combination of overfishing and cooler temperatures proved 
PARAGRAPH_XXO deadly in the late 1960s.  Cod stocks collapsed, making only 
PARAGRAPH_XXO feeble recoveries following warmer periods in the 1970s and 
PARAGRAPH_XXO 1980s.  As temperatures fell below about 1.8 C, local stocks 
PARAGRAPH_XXO could not reproduce.  A final peak of fishing effort in the late 
PARAGRAPH_XXO 1980s finished off the remaining cod. 
PARAGRAPH_XXO The elimination of cod, a top predator, has been followed by an 
PARAGRAPH_XXO increase in the abundance of northern shrimp (Pandalus borealis).  
PARAGRAPH_XXO These provide the basis for a new west Greenland fishery.  Shrimp 
PARAGRAPH_XXO catches appear less sensitive to temperature, but grew 
PARAGRAPH_XXO dramatically after cod disappeared.  Multiple regression analysis 
PARAGRAPH_XXO finds that cod catches, Fylla Bank temperatures, winter Arctic 
PARAGRAPH_XXO Oscillation (AO) and North Atlantic Oscillation (NAO) indices 
PARAGRAPH_XXO together explain more than 70% of the variance in shrimp 
PARAGRAPH_XXO catches -- or 80%, if smoothed versions of the climate indicators 
PARAGRAPH_XXO are used. 
PARAGRAPH_XXO The main peaks and collapses in cod catches follow warming and 
PARAGRAPH_XXO cooling periods, respectively.  The final cod peak in the late 
PARAGRAPH_XXO 1980s was weak, however, because so little of the spawning stock 
PARAGRAPH_XXO survived to this point.  Shrimp catches ramped up during two 
PARAGRAPH_XXO warming periods, and then remained high once the cod were all 
PARAGRAPH_XXO gone.  Today the shrimp fishery has replaced cod in terms of 
PARAGRAPH_XXO value, but its benefits are distributed differently within 
PARAGRAPH_XXO Greenland society. 
PARAGRAPH_XXO The west Greenland municipalities of Sisimiut and Paamiut have 
PARAGRAPH_XXO been described as "a winner and a loser," respectively, during 
PARAGRAPH_XXO Greenland's cod-to-shrimp transition.  Their stories are not 
PARAGRAPH_XXO simple accounts of environmental determinism, however.  Rather, 
PARAGRAPH_XXO environmental change interacted with social forces to shape the 
PARAGRAPH_XXO divergent outcomes we see today.  Investments made during the 
PARAGRAPH_XXO earlier stage of the transition, when shrimp were found only to 
PARAGRAPH_XXO the north, created structural advantages for northern ports 
PARAGRAPH_XXO (e.g., Sisimiut and Nuuk) that persisted even as the shrimp 
PARAGRAPH_XXO themselves became available further south. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO BIOLOGICAL INVENTORIES AND VITAL SIGNS MONITORING IN NORTHWEST ALASKA'S NATIONAL PARKS

AUTHORS_XXO HEINLEIN, THOMAS A. (1); Wesser, Sara (2); Anderson, Blain (3)

AUTHOR_1_XXO (1) National Park Service, Western Arctic National Parklands; Thomas_Heinlein@nps.gov
AUTHOR_2_XXO (2) National Park Service, Alaska Region Inventory and Monitoring Program; Sara_Wesser@nps.gov
AUTHOR_3_XXO (3) National Park Service, Alaska Region Inventory and Monitoring Program; Blain_Anderson@nps.gov

PARAGRAPH_1_XXO Biological Inventories and Vital Signs Monitoring in Northwest Alaska's National Parks
PARAGRAPH_XXO Authors:
PARAGRAPH_XXO Heinlein, Thomas       National Park Service, Western Arctic National Parklands,
PARAGRAPH_XXO 		       2525 Gambell, Anchorage, AK  99503
PARAGRAPH_XXO Wesser, Sara 	       National Park Service, Alaska Region Inventory and 
PARAGRAPH_XXO                        Monitoring Program, 2525 Gambell, Anchorage, AK  99503
PARAGRAPH_XXO Anderson, Blain	       National Park Service, Alaska Region Inventory and 
PARAGRAPH_XXO                        Monitoring Program, 2525 Gambell, Anchorage, AK  99503
PARAGRAPH_XXO The USDI National Park Service (NPS) has embarked upon an ambitious plan to incorporate science-based decision making into Park resource management, through the Natural Resource Challenge (NRC) program.  One important aspect of the NRC is to complete baseline biological inventories and create ecological "vital signs monitoring" programs in every NPS unit that contain significant natural resources.  In northwest Alaska, five National Park units have been combined to form the 21.4 million acre Northwest Alaska Inventory and Monitoring Network (NWAN).  One of four networks in Alaska, the NWAN encompasses vast, pristine areas that include Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Noatak National Preserve, Kobuk Valley National Park, and Gates of the Arctic National Park and Preserve.  Within these Park units, there are a number of unique biogeographic features such as the Brooks Range, Great Kobuk Sand Dunes, the Kobuk and Noatak Rivers, and the archeologically rich beach ridges of Cape Krusenstern. The NWAN holds great potential as an outdoor laboratory to gain scientific insight regarding a number of Arctic-related issues such as global climate change, arctic haze, and the deposition of persistent organic pollutants.  
PARAGRAPH_XXO NWAN Parks are relatively new additions to the NPS System, with all of the Network Units being established in 1980.  To date, no comprehensive inventory efforts have been undertaken, and there are few data available that accurately access baseline biological conditions.  After a thorough review of existing information and a prioritization of needs, the NWAN initiated biological inventories in 2001.  Inventories are scheduled for the next four years and will target specific information gaps.  The goals of these biological inventories are: 
PARAGRAPH_XXO 1. To document, through existing data and targeted field investigations, the occurrence of at least 90% of vertebrate and vascular plant species expected to occur in NPS units. 
PARAGRAPH_XXO 2. To describe the distribution and relative abundance of species of special concern, such as Threatened and Endangered species, exotics, and other species of special management interest, occurring within unit boundaries. 
PARAGRAPH_XXO 3. To provide the baseline information needed to develop a monitoring strategy and design, tailored to specific park threats and resource issues.   
PARAGRAPH_XXO Projects currently underway include inventories of vascular plants, small mammals, and montane-nesting birds.  Preliminary data show significant range extensions for several species of small mammals and the discovery of at least two vascular plant species never before documented in North America.   Additional projects are proposed to inventory non-vascular plants and develop a plant community classification system for NWAN.
PARAGRAPH_XXO   
PARAGRAPH_XXO The second phase of the NPS I&M Program is the development of a "Vital Signs Monitoring" program, (designed to build upon the knowledge gained from baseline biological inventories), to provide long-term monitoring for key indicators of change.   The Vital Signs Monitoring program will be designed to focus on a number of issues affecting NWAN Parks including ecosystem responses to global climate change, arctic haze, and airborne pollutants.  The NWAN Vital Signs Program is scheduled to receive initial funding in 2003.  
PARAGRAPH_XXO Preliminary planning is underway to design a thoughtful, inclusive monitoring program that will compliment existing arctic research efforts.  A current example of this cooperation is a shared air-quality monitoring project between the NPS and the US Environmental Protection Agency (EPA), to conduct air and water quality monitoring within Noatak National Preserve.  The project will establish important baseline information regarding the accumulation of persistent organic pollutants (POPS), mercury, and other heavy metals and will result in the construction of permanent air sampling stations that will be valuable to future vital signs monitoring efforts.
PARAGRAPH_XXO       

INSERT_PAGE_BREAK_HERE
TITLE_XXO UIVVAQ: CLIMATE, POLITICS, AND THULE ORIGINS IN NORTHWEST ALASKA

AUTHORS_XXO HOFFECKER, JOHN F. (1); Elias, Scott A. (2); Reynolds, Georgeanne L. (3); Mason, Owen  K. (4); Hanson, Diane K. (5); Leeper, Karlene (6)

AUTHOR_1_XXO (1) INSTAAR; hoffecke@spot.colorado.edu
AUTHOR_2_XXO (2) INSTAAR/University of London
AUTHOR_3_XXO (3) US Army Corps of Engineers
AUTHOR_4_XXO (4) University of Alaska
AUTHOR_5_XXO (5) US Army Corps of Engineers
AUTHOR_6_XXO (6) US Air Force

PARAGRAPH_1_XXO Interdisciplinary study of Uivvaq (Located at Cape Lisburne on the coast of the Chukchi Sea) began in 2000 and is designed to develop a high-resolution chronology for culture and climate change in northwest Alaska during the late Holocene.  This chronology will be used to address the problem of Thule origins, which may be related to both climate and political conflict in the region.  Uivvaq was occupied by families with ties to Tikigaq prior to AD 1950, members of whom are providing an oral history of the site.  A trench excavated into the second deepest midden revealed a stratified sequence of occupations dating to the past 1500 years (based on AMS dating of insect fragments).  Both Birnirk and Thule appear to be represented by diagnostic artifact types.  The lower occupations overlap temporally with the large Ipiutak settlement at Point Hope (less than 50 km to the southwest), but suggest no influences from the latter.  Seal and walrus dominate the large mammal remains and probably reflect winter habitation.  Local paleotemperature estimates (Based on analysis of fossil beetles recovered from the midden deposits) indicate several warm and cool oscillations during the past 1500 years.

INSERT_PAGE_BREAK_HERE
TITLE_XXO LATE GLACIAL AND HOLOCENE CLIMATE AND ENVIRONMENTAL VARIABILITY ON SVALBARD 

AUTHORS_XXO HOLMGREN, SOFIA

AUTHOR_1_XXO Department of Geology, Goteborg University, Sweden; sofiah@gvc.gu.se

PARAGRAPH_1_XXO Arctic regions are sensitive to climate changes, and the rise in global mean temperature, observed since the mid- 19th century, has raised concerns about the Arctic ecosystems. To strengthen our understanding of natural variability and the role of anthropogenic forcing in controlling climate, reconstructions of past climate are needed in order to put the present temperature changes in a long-term perspective. Recently, considerable effort has been given to obtain multi-proxy data sets from around the Arctic, i e the Canadian and Russian Arctic, in order to produce reconstructions of palaeoclimate, but additional high resolution studies are still required for the Svalbard archipelago (80ºN, Norway). 
PARAGRAPH_XXO The aim of this project is to reconstruct the late glacial and Holocene climate changes and environmental variability on Svalbard. The reconstruction will be based upon high resolution analyses of lake sediments derived from western Spitsbergen (Svalbard archipelago). So far, six lakes have been cored in an area south of Isfjorden, and new cores will be collected from Broggerhalvoya, south of Kongsfjorden, in spring 2002.
PARAGRAPH_XXO A number of analyses, including analyses of diatoms, biogenic silica, chironomids, macrofossils, C/N ratio, carbon and nitrogen content, and others, will be applied to the sediment sequences to trace the occurrence of shifts in the ecosystem. These records will provide palaeoclimatic information and help revealing the pattern of early/mid Holocene warming, Neoglacial cooling, the Little Ice Age and temperature variability during the past 150 years.

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE HARC INITIATIVE: OPPORTUNITIES AND DIRECTIONS

AUTHORS_XXO HUNTINGTON, HENRY P.

AUTHOR_1_XXO Huntington Consulting/HARC SMO; hph@alaska.net

PARAGRAPH_1_XXO Humans have long been part of the Arctic system. In recent decades, their influence on the Arctic has increased greatly. Many of the ways in which the Arctic affects humans have also changes, some significantly and some subtly or not at all. To examine these and related aspects of the Arctic system, NSF started the Human Dimensions of the Arctic System (HARC) initiative in 1997, with the issuance of the HARC Prospectus. Unfortunately, response to the initiative has been lower than anticipated. In 2000, the ARCSS Committee recommended establishing a Science Management Office (SMO) for HARC, as has been done for other ARCSS components. In 2001, the HARC SMO began operation. This presentation describes the activities and plans of the SMO, and encourages investigators to create research partnerships in the social and natural sciences in order to develop this initiative further. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO DISCHARGE AND SUSPENDED SEDIMENT DYNAMICS OF HIGH-ARCTIC COLD AND POLYTHERMAL GLACIERS

AUTHORS_XXO IRVINE-FYNN, TRISTRAM DL. (1); Willis, Ian C. (2); Mumford, Paul N. (3); Hodson, Andrew J. (4)

AUTHOR_1_XXO (1) Department of Geography, University of Calgary; tdlirvin@ucalgary.ca
AUTHOR_2_XXO (2) Department of Geography, University of Cambridge; iw102@cus.cam.ac.uk
AUTHOR_3_XXO (3) Department of Geography, Sheffield University; p.n.mumford@sheffield.ac.uk
AUTHOR_4_XXO (4) Department of Geography, Sheffield University; A.J.Hodson@sheffield.ac.uk

PARAGRAPH_1_XXO The discharge (Q) and suspended sediment (SS) dynamics of streams draining temperate glaciers has been more thoroughly researched than that of streams draining cold and polythermal glaciers. Recent studies undertaken have suggested glacier thermal regime exerts an important control on Q and SS dynamics in proglacial streams. Subglacial processes are dominant in temperate glaciers leading to high SS concentrations early in the ablation season that rapidly decline as discharge increases through the season as a hydraulically-inefficient subglacial drainage system is replaced by a more efficient one. Conversely, ice marginal processes are more important at cold and polythermal glaciers and SS concentrations tend to remain constant or increase during the ablation season. 
PARAGRAPH_XXO A problem with previous comparative studies at non-temperate glaciers is that they have tended to rely on data collected from non-neighbouring glaciers (with differing sizes, climates and geologies) and in some cases over different time periods and with different sampling techniques. 
PARAGRAPH_XXO This research was conducted using identical methods, simultaneously, at the adjacent and geometrically similarly Midre Lovenbreen (a polythermal glacier) and Austre Broggerbreen (a cold glacier) near Ny Alesund, Svalbard. From 22nd June to 10th August 2000, proglacial streams were monitored for Q and SS concentration variations. Air temperature and precipitation were also recorded at Midre Lovenbreen.
PARAGRAPH_XXO Data were analysed using bivariate and multi-variate statistical techniques. The discharge dynamics were strongly linked to the transition from snow-melt to ice-melt dominated glacier drainage at both glaciers. At Austre Broggeerbreen, peak Q lagged behind peak diurnal temperatures, with a decrease in the lag time over the course of the season. On Midre Lovenbreen, a similar lag was seen over the former half of the season. However, Q became 'decoupled' from air temperature forcing and there were substantial increases in proglacial SS concentrations when a subglacially-fed up-welling broke through the cold-based margin of this polythermal glacier on July 16th. These changes did not occur at the cold-based Austre Broggerbreen. 
PARAGRAPH_XXO The Q and SS time-series from both glaciers were split into pre- and post-upwelling periods. At Austre Broggerbreen diurnal SS variations led Q variations during both sub-periods indicative of negative hysteresis, with rate of change in Q forcing SS variations. At Midre Lovenbreen, however, the lack of any apparent hysteresis was suggestive of more complex controls. Multivariate regression analysis suggests that SS dynamics are primarily forced by ice marginal discharge fluctuations throughout the summer at Austre Broggerbreen but that SS variations were also influenced by frequent, random fluctuations in subglacial sediment supply at Midre Lovenbreen in the post-upwelling period. This notion of the sub-glacial system's importance was supported by the respective seasonal SS yields. Furthermore, there was evidence of sediment exhaustion at Midre Lovenbreen during the post-upwelling period, suggesting the possibility of subglacial drainage system evolution, similar to that documented for temperate glaciers. Finally, multivariate and auto-regressive integrated moving average (ARIMA) analysis indicated that at both glaciers SS concentrations depended on previous SS values indicating temporally discontinuous 'flushes' and tapping of new sediment supplies, possibly derived from spatially variable paraglacial and cryogenic inputs. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO WAS THE YOUNGER DRYAS (GS-1) A COLD PERIOD ON THE SOUTHEAST GREENLAND MARGIN?

AUTHORS_XXO JENNINGS, ANNE E. (1); Hald, Morten (2); Weiner, Nancy J. (3); Kaufman, Kris (4); Dunhill, Gita (5); Andrews, John T. (6)

AUTHOR_1_XXO (1) INSTAAR, Univ. of Colorado; jenninga@spot.colorado.edu
AUTHOR_2_XXO (2) University of Tromsoe; Morten.Hald@ibg.uit.no
AUTHOR_3_XXO (3) INSTAAR, Univ. of Colorado; weinern@spot.colorado.edu
AUTHOR_4_XXO (4) INSTAAR, Univ. of Colorado; Kristen.Kaufman@Colorado.EDU
AUTHOR_5_XXO (5) INSTAAR, Univ. of Colorad; Gita.Dunhill@colorado.edu
AUTHOR_6_XXO (6) INSTAAR, Univ. of Colorad; andrewsj@spot.colorado.edu

PARAGRAPH_1_XXO The Younger Dryas stadial event is documented in lacustrine and marine proxy climate records in Northwest Europe and the Nordic Seas as a cold period at the end of the last glacial stage.  It is well expressed in the GRIP and GISP ice cores at the summit of the Greenland Ice Sheet as a deep annual cooling of 10-20°C.  The Younger Dryas cooling has been dated in the GRIP ice core to extend from 12,650 to 11,500 cal. yr BP and has been proposed to be termed Greenland Stadial 1 (GS-1).  Several marine cores from the Kangerlussuaq Trough, East Greenland contain sediment records that extend from deglaciation (c. 15-16 cal. ka BP) through the Holocene, and thus contain sediments deposited during GS-1.  Two tephras, the Vedde Ash (11,980 ± cal yr BP) which is a marker bed within GS-1, and the Saksunarvatn tephra (10,180 ± cal. yr BP) an early Holocene marker horizon, have been located in these cores.  The tephras and calibrated 14C dates on foraminifers and molluscs provide the basis for the age models in the cores.  Studies of benthic and planktic foraminiferal assemblages and stable O and C isotopes yielded a surprising result: the Kangerlussuaq Trough cores do not show evidence for  cooling in GS-1 until c. 12 cal. ka BP.  Strong evidence of inflow of Atlantic Intermediate waters into the Kangerlussuaq Trough beginning c. 15 cal. ka BP continues in GS-1 until c. 12 cal ka BP. This interpretation is based on high percentages of the Atlantic Intermediate Water indicator species, Cassidulina neoteretis.  The transition from Greenland Interstadial-1 (Bølling/Allerød) to GS-1 is unmarked by evidence for environmental change.  However, a significant light _18-O spike is centered within GS-1 in the middle/inner shelf cores and coincides with a decline in the percentages of C. neoteretis.  The light isotope interval is absent or unpronounced on the outer shelf.  Because it is most pronounced closer to the coast, this light isotope anomaly is interpreted as a meltwater spike reflecting melting of the ice sheet margin during GS-1.  In contrast, a core from a site north of Kangerlussuaq Trough (MD99-2317) shows a large faunal change at the transition to GS-1 as well as lithostratigraphic changes indicating cooling.  This core has low percentages of C. neoteretis, even in GI-1.  These comparisons and spatial differences suggest that the Atlantic Intermediate Water influx in the Kangerlussuaq Trough in the deglaciation was carried onto the East Greenland shelf in the Irminger Current, as occurs today.

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE ORGANO-GEOCHEMICAL RECORD FROM THE ANDFJORDEN, NORTHERN NORWAY: PALEOPRODUCTIVITY DURING THE LATE GLACIAL ÑEARLY HOLOCENE

AUTHORS_XXO KNIES, JOCHEN (1); Hald, Morten (2); Ebbesen, Hanne (3)

AUTHOR_1_XXO (1) Geological Survey of Norway, Trondheim, Norway; jochen.knies@ngu.no
AUTHOR_2_XXO (2) University of Tromsù, Tromsù, Norway; morten.hald@ibg.uit.no
AUTHOR_3_XXO (3) University of Tromsù, Tromsù, Norway; hanne@ibg.uit.no

PARAGRAPH_1_XXO In this paper, we investigated the organic geochemical record from the Andfjorden, northern Norway, emphasising particularly on the rapid transition during the Bølling/Allerød - Younger Dryas - Early Holocene climate oscillations. The age model of sediment core JM99-1200 (69°15.95 N, 16°25.09 E; 476 mbsf; ~11 m core length) is based on six AMS 14C datings done on macrofossils. The record shows an undisturbed sequence with sedimentation rates up to 634 cm/kyr. We sampled the record every 5 cm revealing a resolution of up to ~10 years/sample. 
PARAGRAPH_XXO Technically, we performed total organic carbon (TOC), carbonate (CaCO3) and biogenic opal analyses. We looked at the organic carbon composition by studying the stable isotope composition of TOC and nitrogen, the TOC/nitrogen ratio, the kerogen types by Rock Eval pyrolysis, and various biomarkers indicating the supply of marine, and terrigenous organic matter. We calculated accumulation rates based on linear sedimentation rates and dry bulk density data and terrigenous free relative percentages of the biogenic components.
PARAGRAPH_XXO The perfect fit between carbonate weight percent and planktic forams/g Sediment from nearby record T-79-51/2 (R2= 0.92) (Hagen 1995) suggests a biogenic origin of the carbonate fraction in JM99-1200. Variable sedimentation rates from ~46 to 634 cm/kyr, however, modulated significantly the carbonate record. In contrast, calculations of terrigenous free relative percentages show two distinct carbonate maxima, one before (Allerød) and one after (Early Holocene) the Younger Dryas cold period. The overall good correlation (R2= 0.8) between the terrigenous free relative percentages of biogenic carbonate and the &#61540;13C values of the organic matter led to the assumption that the marine organic matter input is closely coupled to the biogenic carbonate production. The TOC record seems not to be influenced by variable sedimentation rates as the CaCO3 record does. Instead, three distinct TOC minima are coupled with changes in the grain size distribution, i.e. increased sand input. According to Canfield (1994), constant preservation of organic carbon at accumulation rates greater than 0.04 g cm-2 yr-1 is suggested. However, we cannot exclude a distinct clastic dilution effect at sedimentation rates up to ~600 cm/kyr. In order to avoid modulation of paleoproductivity estimations by applying a constant linear sedimentation rate model, we calculated the relative amounts of marine and terrigenous organic matter input by using a simple two endmember mixing model based on stable carbon isotopes of the organic matter. We defined a marine endmember value of -20.3 ‰ and used a generally accepted terrigenous endmember for the study area of -27 ‰. The results indicate a predominance of marine organic matter input throughout the record (up to 80 % during the Holocene Climate Optimum). Freshwater supply is rather limited as indicated by subordinate concentrations of freshwater dinocysts (e.g. Pediastrum) (K. Grøsfjeld, pers. comm.) and does not modulate the record. Despite variable sedimentation rates and possible dilution effects, we suggest that the relative amounts of marine organic carbon can be used as surface water productivity indicator in the Andfjorden. Characteristic cold periods, like the Older Dryas, the Intra-Allerød Cold Period (IACP) and the 8.200 cold event are marked by a 30 % drop in marine organic carbon input and a parallel increase in terrestrial organic matter supply due to enhanced glacial fluctuations. 

REFERENCE_XXO Canfield, D.E., 1994, Factors influencing organic carbon preservation in marine sediments: Chemical Geology, v. 114, p. 315-329.
REFERENCE_XXO Hagen, S., 1995, Watermass characteristics and climate in the Nordic sea during the last 10.200 years: Unpublished Master Thesis, Institute of Biology and Geology, University of Tromsù, Norway, pp. 100

INSERT_PAGE_BREAK_HERE
TITLE_XXO A NEW CHRONOLOGICAL CONCEPT FOR THE EASTERN ARCTIC OCEAN

AUTHORS_XXO KNIES, JOCHEN  (1); Matthiessen, Jens (2); Nowaczyk, Norbert (3); Stein, Ruediger  (4); Vogt, Christoph (5); Wollenburg, Jutta (6)

AUTHOR_1_XXO (1) Geological Survey of Norway; jochen.knies@ngu.no
AUTHOR_2_XXO (2) Alfred Wegener Institute for Polar and Marine Research; jmatthiessen@awi-bremerhaven.de
AUTHOR_3_XXO (3) GeoForschungsZentrum Potsdam; nowa@gfz-potsdam.de
AUTHOR_4_XXO (4) Alfred Wegener Institute for Polar and Marine Research; rstein@awi-bremerhaven.de
AUTHOR_5_XXO (5) University of Bremen; cvogt@min.uni-bremen.de
AUTHOR_6_XXO (6) Alfred Wegener Institute for Polar and Marine Research; jwolenburg@awi-bremerhaven.de

PARAGRAPH_1_XXO Problems and constrains in dating late Quaternary Arctic Ocean sediments
PARAGRAPH_XXO Studies on sedimentary records from the central and eastern Arctic Ocean with sedimentation rates up to ~3 cm/ka have highlighted the tremendous impact of the Arctic Ocean freshwater budget on world climate during major deglacial phases, i.e. the last glacial/interglacial and the marine oxygen isotope (MIS) 4/3 transition. However, the sometimes enigmatic and discontinuous stable oxygen isotope records limit the precision of paleoenvironmental interpretations. Various approaches including sedimentological, physical and –micropaleontological methods have been applied to establish a chronostratigraphy but low preservation and discontinuous records of biogenic material and equivocal interpretations of paleomagnetic and radionuclide records limit the stratigraphic resolution of the different methods.
PARAGRAPH_XXO Multi-proxy stratigraphic concept
PARAGRAPH_XXO Our new strategy for tackling these ongoing chronostratigraphic problems integrates various chronostratigraphic approaches to date records from the marginal eastern Arctic Ocean that underlies the submerging Atlantic-water derived intermediate waters (Fig. 1). We chose the Yermak Plateau – the Atlantic/Arctic Ocean gateway – as key area for our study because, (1) here, rather than in central Arctic Ocean, carbonate bearing sequences permit establishment of a relatively continuous stable oxygen isotope stratigraphy, which is still the prerequisite for any subsequent application of chronological approaches, and (2) the dynamic coupling between the northernmost branch of the Gulf Stream and the Arctic Ocean – possibly one of the decisive factors controlling rapid climate changes – is best studied in our key area. Once the records are exactly dated, they may provide useful stratigraphic reference sections for central Arctic Ocean records underlying the submerging Atlantic-water derived intermediate waters. We have selected three locations of high priority (PS2138, PS1533, PS1535) and two locations of lower priority (PS2837, PS2123). At these sites previous studies have shown that a well-constrained chronostratigraphy can be established but, unfortunately, almost no core material is left for additional studies (Fig. 1). Our main goal is to strengthen the reliability of Arctic Ocean chronology and establish a new, fundamental basis for generating high-resolution paleoenvironmental reconstructions in the Arctic Ocean.
PARAGRAPH_XXO Sediment core PS2138 as one example
PARAGRAPH_XXO The chronology in core PS2138 recovered from the marginal eastern Arctic Ocean is based on the oxygen isotope stratigraphy performed on planktic and benthic foraminifera, 24 AMS14C dates back to 31 14C ka B.P., geomagnetic excursions, radioistopic signals, micropaleontological evidences and deduced paleoproductivity fluctuations as well as the correlation of ice rafted debris (IRD) events to the polar marine events in the North Atlantic. The bulk of direct and indirect age tie points available from this record over the past 150.000 years highly strengthens the reliability of paleoenvironmental reconstruction in the area even on timescales <1000 years. 

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/11-1.GIF

CAPTION_XXO Fig 1.  

INSERT_PAGE_BREAK_HERE
TITLE_XXO ENDOGENIC FEATURES IN THE SOUTH POLAR REGION OF MARS AND POSSIBLE TERRESTRIAL ANALOGUES

AUTHORS_XXO KOUTNIK, MICHELLE R. (1); Murray, Bruce (2); Byrne, Shane (3)

AUTHOR_1_XXO (1) University of Calgary; mkoutnik@ucalgary.ca
AUTHOR_2_XXO (2) California Institute of Technology; bcm@gps.caltech.edu
AUTHOR_3_XXO (3) California Institute of Technology; shane@gps.caltech.edu

PARAGRAPH_1_XXO The narrow angle (NA) Mars Orbiter Camera (MOC) aboard the Mars Global Surveyor (MGS) mission has provided detailed imagery of the South Polar Layered Deposits (SPLD) and the south polar residual cap revealing features previously unable to be identified.  There are a multitude of features we have found and believe that they have a possible endogenic origin as opposed to being impact craters.  The observed endogenic features often have particular associations and negative, circular, but non crater-like forms. The presented features in different areas of the south polar region have different morphological characteristics.  
PARAGRAPH_XXO The region of the SPLD from at least 190 - 230 W, 85 - 87 S, just west of Chasma Australe, is the primary location for a different clustering of negative, circular pits.  This area is topographically unique because of the extensive grooves of an undetermined origin cut into it.  We have informally termed this grooved area the ?wire brush? region and it is shown in Figure 1. We have not recognized such a pattern elsewhere on Mars and only in one other small area in the SPLD. It is suggestive of erosion by an external agent that maintained a coherent pattern over several hundred kilometers scale, such as wind or glaciation.  The pits in this region are all approximately 10 ? 100 m in diameter and have been ruled out as small primary impact craters or secondary craters based on the lack of crater-like associations and the high number of features observed over this entire area. A significant association that has been noted in some images is that the pits can be grouped in circular patches of slightly lower topography over a particular region, as shown in Figure 2. Other pit-like features are noted in different areas on the SPLD, particularly from at least 120 - 190 W, 85 - 87 S.  An example of these features, shown in Figure 3, exhibit more irregularities in shape and are also frequent over this region.  
PARAGRAPH_XXO There are terrestrial features that have the same size range and are similar in appearance and distribution to the south polar pits.  These glacial potholes are thought to occur in association with glacial surging on Earth but a detailed process of formation is not well constrained [Post and LaChapelle, 1971; Sturm, 1987].  The analogue to the observed Martian features is only by appearance and size distribution thus far.  The possibility for a similar mechanism of formation has not yet been determined and as well other terrestrial analogues are also considered.  Another possibility is that these features may be associated with the termed Martian ?swiss cheese? terrain found on the residual cap [Ingersoll et al., 2000; Thomas et al., 2000]. 
PARAGRAPH_XXO The origin of these endogenic features has not been determined and it is possible that different mechanisms are responsible for the features on the residual cap and on different regions of the SPLD. These features are most unlikely impact craters or secondary populations and may indicate characteristics of south polar processes and will likely provide insight into the past south polar environment.<br>

REFERENCE_XXO Ingersoll, A.P., et al., 2000, Spring and Summer Changes at the south pole as seen by the Mars Orbiter Camera,  Mars Polar Science II (2000), #4076.
REFERENCE_XXO Post, Austin and LaChapelle, Edward. Glaicer Ice. University of Washington Press, 2000, pg. 78-79.
REFERENCE_XXO Sturm, M., 1987, Observations on the Distribution and Characteristics of Potholes on Surging Glaciers, Journal Geophys. Res. 92, 9015-9022.
REFERENCE_XXO Thomas, P.C., et al., 2000, North-South geological differences between the residual polar caps on Mars,  Nature 404, 161-163.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/31-1.JPG

CAPTION_XXO Fig 1.  "Wire brush" region of the SPLD, at least 190 - 230 W, 85 - 87 S.  This is also the primary location of circular, negative pits we highlight here. The origin of these extensive grooves is unknown but suggestive of glaciation.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/31-2.JPG

CAPTION_XXO Fig 2.  Portion of MOC NA frame m110-2900, at 87 S, 203 W.  This image shows the circular, negative pits grouped within larger circular, negative depressions.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/31-3.JPG

CAPTION_XXO Fig 3.  MOC NA frame m110-0014, at 87 S, 148 W.  This image shows a morphologically different distribution of circular, negative pits in the region 120 -190, 85 -87 S.  As apparent in this image, these pits are often linearly linked together.

INSERT_PAGE_BREAK_HERE
TITLE_XXO HOLOCENE HEKLA TEPHRAS: A STRATIGRAPHIC TOOL FOR ESTIMATING CHANGES IN RESERVOIR AGE OF SEAWATER.  CORE MD99-2269, NW-ICELAND SHELF

AUTHORS_XXO KRISTJANSDOTTIR, GRETA B.

AUTHOR_1_XXO INSTAAR and Department of Geological Sciences, University of Colorado, Boulder, CO; gbk@colorado.edu

PARAGRAPH_1_XXO An abundance of traceable and dated tephra layers from Icelandic volcanoes offer a unique opportunity for land-sea correlations and determination of reservoir age of seawater around Iceland.  An offset of tephra markers from an established radiocarbon-based age model can be interpreted as a change in reservoir age of the water.  A study by Eiriksson et al. (2000) on the central N-Iceland shelf has suggested an increase in the reservoir age of seawater by 130 yrs during late Holocene (3000-850 cal BP).  This is tentatively related to increasing influence of colder (and older) water from the east Iceland current on the N-Iceland shelf.  The objective of this study is to examine whether similar changes in reservoir age of sea water occurred on the NW-Iceland shelf.  
PARAGRAPH_XXO Core MD99-2269 is a 2533 cm long marine sediment core located in 365 m water depth in the Reykjafjardarall basin, NW Iceland shelf.  The core, which was cored during the international IMAGES V cruise in 1999, is located in an important oceanographic location with fluctuating influence of the warm Irminger Current coming from the south and the cold East Iceland Current coming from the north.  The core consists of olive-grey silty-clay with ice rafted debris at the base.  Nine AMS radiocarbon dates, calibrated by assuming a constant 400 yr reservoir age and CALIB 4.3, indicate a remarkable linear sedimentation rate of 5 yrs per cm from present back to 12,278 +/- 518 cal BP.  We have recently submitted two more samples for AMS radiocarbon dating to verify the age model.   
PARAGRAPH_XXO Two major tephra markers have been identified via geochemistry in the core and core catcher.  The basaltic Saksunarvatn tephra (9,000 14C BP or 10,180 +/- 60 cal BP) is found as a distinct layer at 2118-2121 cm, whereas shards of rhyolitic Vedde (10,300 14C BP or 11980 +/- 80 cal BP) type composition where found in the core catcher.  The Saksunarvatn tephra falls right on the linear age model of core MD99-2269.  Andrews et al. (subm) has previously noted that a 400 yr reservoir correction is appropriate for this location during deposition of the Saksunarvatn tephra.  
PARAGRAPH_XXO Distribution maps of several Holocene tephras, particularly rhyolitic tephras from the Icelandic volcano Hekla (Hekla 1, Hekla 3, Hekla 4, and Hekla 5, dated at 846, 3008, 4201, and 6950 cal BP respectively), indicate a distribution of airborne tephra (< 0.5-1 cm layer thickness) over the location of core MD99-2269.  However, only the Saksunarvatn tephra marker is visible in the core.  Other tephra markers have to be located by grain counting under a microscope.  Grains were counted in samples previously prepared for foraminifera analyses, using the size fraction >150 µm.  The samples were split until they could evenly cover a counting tray, then 1 cm2 squares were randomly selected for counting until at least 300 grains were counted.  Mud clumps and fecal pellets were counted, but not included in the total count of 300 grains.  
PARAGRAPH_XXO Much of the sediment on the Iceland shelf is tephra and it is crucial to be able to distinguish primary tephra layers from reworked tephra.  Primary tephra layers are assumed to consist of an abundance of fresh tephra shards.  The fresh tephra was differentiated from the reworked tephra mainly on the basis of having sharp, clean edges whereas the reworked tephra has duller edges.  The fresh tephra also tends to look shiny under the microscope compared to the matter reworked tephra.  The counted grains were classified into the following categories: 1) Fresh dark-colored tephra, 2) Fresh light-colored tephra, 3) Other lithics, 4) Biogenic material, and 5) Other material.  The first two categories were intended to identify peaks in fresh tephra grains, which presumably coincide with primary tephra layers.  In contrast, other lithics included material not associated with primary tephra layers such as rock fragments, crystal fragments, and reworked tephra.  Biogenic material included foraminifera, diatoms, and mollusk fragments (sponge spicules were not counted), whereas other material consisted mainly of greenish organic material and a few unidentified grains.  
PARAGRAPH_XXO Once peaks of fresh tephra have been identified samples are taken for geochemical analyses.  A few preliminary samples have been analyzed, but they show enrichment in Fe and Al, and depletion in Na and K relative to any published geochemical tephra analyses.  The preliminary samples were not taken from the tephra peaks and we are hoping to get better analyses when analyzing tephra from the peak samples.  

REFERENCE_XXO Andrews, J. T., Geirsdottir, A., Hardardottir, J., Principato, S., Krisjansdottir, G. B., Helgadottir, G., Gronvold, K., Drexler, J. & Sveinbjornsdottir, A. (subm.) Distribution, age, sediment magnetism, and geochemistry of the Saksunarvatn (10.18 ± cal ka) ash in marine, lake, and terrestrial sediments, NW Iceland.
REFERENCE_XXO Eiriksson, J., Knudsen, K. L., Haflidason, H. & Heinemeier, J. (2000) Chronology of late Holocene climatic events in the northern North Atlantic based on AMS 14C dates and tehpra markers from the volcano Hekla, Iceland. Journal of Quaternary Science, 15(6), 573-580.

INSERT_PAGE_BREAK_HERE
TITLE_XXO SUSTAINABILITY OF ARCTIC COMMUNITIES: AN INTERDISCIPLINARY COLLABORATION OF RESEARCHERS AND LOCAL KNOWLEDGE HOLDERS

AUTHORS_XXO KRUSE, JACK (1); White, Bob (2); Griffith, Brad (3); Chapin, Terry (4); Kofinas, Gary (5); Berman, Matt (6); Epstein, Howard (7); Nicolson, Craig (8)

AUTHOR_1_XXO (1) University of Alaska Anchorage; afjak@uaa.alaska.edu
AUTHOR_2_XXO (2) University of Alaska Fairbanks; ffrgw@uaf.edu
AUTHOR_3_XXO (3) Alaska Cooperative Fish and Wildlife Unit; ffdbg@aurora.alaska.edu
AUTHOR_4_XXO (4) University of Alaska Fairbanks; terry.chapin@uaf.edu
AUTHOR_5_XXO (5) University of Alaska Anchorage; gary.kofinas@dartmouth
AUTHOR_6_XXO (6) University of Alaska Anchorage; auiser@uaa.alaska.edu
AUTHOR_7_XXO (7) University of Virginia; hee2b@virginia.edu
AUTHOR_8_XXO (8) University of Massachusetts; craign@forwild.umass.edu

PARAGRAPH_1_XXO How will climate change affect the sustainability of Arctic communities over the next forty years? This is the question that motivated a four-year collaboration of 23 researchers and four Arctic communities: Old Crow YT, Aklavik NT, Arctic Village AK, and Fort McPherson NT. This article provides an overview of results of the first phase of this ongoing study.
PARAGRAPH_XXO We drew on existing research and local knowledge to examine how the combined effects of climate change, petroleum development, tourism, and government cutbacks might change the sustainability of Arctic villages. The project's four partner communities defined sustainability in terms of five community goals. We worked together to incorporate research and local knowledge-based understandings in a spreadsheet-based Synthesis Model and a web-based Possible Futures Model. We used these models to run and present experimental simulations linking scenario choices with output indicators. We modeled vegetation changes, caribou population dynamics, local labor markets, mixed subsistence and cash economies, and oil field-caribou interactions. The user can view an explanation of which modeled relationships are responsible for the observed simulation results for a chosen indicator. The Possible Futures Model includes a feedback capability so that remote users and meeting participants can communicate their own thinking to the research team. 
PARAGRAPH_XXO Simulation results suggest that climate warming will increase total plant biomass for high and low Arctic tundra ecosystems. Year-to-year variations in caribou population dynamics can mask or accentuate the apparent effects of climate warming and petroleum development; however, the PCH is more likely to decline under climate warming. Simulations suggest a 45 kilometer displacement of cows and calves during a three-week period in June would be sufficient to halt growth the PCH. Under most simulations, producing a decline in community harvests would take climate warming coupled with displacement of cows and calves from all of the coastal plain during a three week period in June.
PARAGRAPH_XXO For additional materials regarding this continuing study, please visit our project website at: http://www.taiga.net/sustain or contact Jack Kruse at afjak@uaa.alaska.edu 

INSERT_PAGE_BREAK_HERE
TITLE_XXO ESTIMATING BIOPHYSICAL CHARACTERISTICS OF ARCTIC TUNDRA VEGETATION USING SOIL-ADJUSTED VEGETATION INDICES AND MULTI-RESOLUTION REMOTE SENSING DATA 

AUTHORS_XXO LAIDLER, GITA J. (1); Treitz, Paul M. (2)

AUTHOR_1_XXO (1) Queen's University; gita_laidler@yahoo.com
AUTHOR_2_XXO (2) Queen's University; pt6@qsilver.queensu.ca

PARAGRAPH_1_XXO The Normalized Difference Vegetation Index (NDVI) is the most commonly applied spectral vegetation index (VI) in arctic biophysical remote sensing analysis.  However, due to the low stature and patchy nature of vegetation cover in the dwarf-shrub tundra sub-zone, it is important to investigate the utility of VIs that compensate for high degrees of soil reflectance.  Therefore, the objectives of this study are to explore the relationships between soil-adjusted VIs, percent cover, and vascular plant biomass, in a tundra environment where exposed soil and gravel till have significant influence on the spectral response, and hence, the characterization of vegetation communities.  In response to previous studies suggesting that high spatial resolution remote sensing data (i.e., <10m) is required for adequate delineation and classification of Arctic tundra vegetation communities, an IKONOS multispectral image (i.e., 4m spatial resolution) was acquired for a study area within the Lord Lindsay River watershed on Boothia Peninsula, Nunavut.  Coincident with image acquisition, extensive field data (e.g. percent cover, above-ground biomass, surface spectral characteristics) were collected to determine community composition.  These data were then used in an evaluation of the performance of an unsupervised classification and spectral vegetation indices (NDVI, SAVI, MSAVI) in describing vegetation community characteristics.  This poster will present a comparison of the application of IKONOS and Landsat 7 ETM+ data for delineating tundra vegetation communities and biophysical properties characterized by small-scale variations in moisture and topographic gradients.  Results suggest that high spatial resolution satellite data provide detailed information on vegetation community structure and biophysical properties, while soil-adjusted VIs provide seemingly more realistic estimates of plant cover and vigor.  As the Arctic tundra is believed to be quite sensitive to minor changes in temperature and/or precipitation, estimates of vegetation community composition, distribution, and biomass are essential to determining a baseline for monitoring or modeling future changes that may follow trends of global climate change.

INSERT_PAGE_BREAK_HERE
TITLE_XXO ASSESSING HYDROLOGIC IMPACTS OF ICE SHEET EXTENT IN NORTHERN EURASIA

AUTHORS_XXO LAMMERS, RICHARD B. (1); Forman, Steven L. (2); Vorosmarty, Charles J. (3)

AUTHOR_1_XXO (1) University of New Hampshire; richard.lammers@unh.edu
AUTHOR_2_XXO (2) University of Illiniois at Chicago
AUTHOR_3_XXO (3) University of New Hampshire; charles.vorosmarty@unh.edu

PARAGRAPH_1_XXO Dramatic changes in the hydrology of Eurasia occurred during the last glaciation.  Discharge of many rivers was probably reduced reflecting colder and dryer climates of the Siberian lowlands.  Potentially, some large drainages were dammed by advancing ice sheets, diverting discharge from the Arctic Ocean to the Black Sea.  Uncertainty persists on the eastern and northern margin of the Eurasian ice sheet, where small changes in extent (10s to 100s km) would progressively impound more northerly river flow.  Ice sheet configurations are based on modifications of the Peltier ice sheet reconstruction with data defensible margins.  Minimum, intermediate, and maximum configurations are represented by an eastern ice sheet limit in the Kara Sea, Taymyr Peninsula coast and western North Siberian Lowland, respectively.  Topographic grid is provided by a contemporary 5-minute resolution global data set, which is regridded to 30-minute resolution.  The river network configuration was derived from automated network delineation methods working off the digital terrain data.
PARAGRAPH_XXO The minimum ice sheet forms a proglacial lake that fills the Kara Sea with drainage to the north.  This proglacial lake and concentrated runoff at the eastern-most margin may have limited expansion of the ice sheet.  The intermediate ice sheet configuration forms a large proglacial lake equal in volume to ¾ of the Caspian Sea.  The Ob' and Yenisey rivers are indirectly blocked with the presence of a contiguous ice sheet between Franz Josef Land, Svernaya Zemlya and the Taymyr Peninsula. Most drainage is routed to the east into the Laptev Sea.  The maximum ice sheet extent directly blocks the Ob' and Yenisey rivers forming a massive proglacial lake, equivalent in volume to two Caspian Seas.  Drainage is shifted to the south resulting in expansion of the Aral, Caspian and Black seas.  These simulations show the importance of the eastern and northern ice sheet margins between Franz Josef Land, Svernaya Zemlya and the Taymyr Peninsula in diverting freshwater flow from the Arctic Ocean.

INSERT_PAGE_BREAK_HERE
TITLE_XXO A 750-YEAR VARVE RECORD FROM THE MARGIN OF THE DEVON ISLAND ICE CAP, ARCTIC ARCHIPELAGO, CANADA

AUTHORS_XXO LAMOUREUX, SCOTT F. (1); Gilbert, Robert (2); Lewis, Ted (3)

AUTHOR_1_XXO (1) Department of Geography Queen's University; lamoureux@lake.geog.queensu.ca
AUTHOR_2_XXO (2) Department of Geography Queen's University; gilbert@lake.geog.queensu.ca
AUTHOR_3_XXO (3) Department of Geosciences University of Massachusetts Amherst; lewist@geo.umass.edu

PARAGRAPH_1_XXO In recent years, a there has been increasing interest in the use of arctic varved lake records (e.g. Lamoureux, 2000, Hughen et al., 2000) to document the long term climate variability from this sensitive region.  Together with other high-resolution proxy records (including ice cores and tree rings on the mainland), these records have shown the first detailed indication of recent environmental and climate change from the region (Overpeck et al., 1997).  Despite these efforts, relatively few records are available and comparing the details of records from widely separated sites can be problematic, particularly in detail.  To address this issue, we initiated research at Bear Lake, Devon Island (75°28’N, 85°10’W) to develop a varve record to compare with the ice core record obtained from the Devon Island Ice Cap (Alt et al., 1985; Koerner and Fisher, 1990).  In addition to collecting sediment cores from the lake, a melt season of detailed sediment trapping and watershed process work was carried out in 1999 to identify the processes that control sedimentation in the lake (Lewis et al., 2002 in press).
PARAGRAPH_XXO Bear Lake is a deep (maximum depth 103 m) basin that receives inflow primarily from a river draining c. 20 km of the northwest margin of the Devon Island Ice Cap.  Discharge begins in June with snowmelt and reaches a maximum on warm days during July when diurnal fluctuations become pronounced.  The river carries substantial fine-grained, carbonate-rich sediment from the ice marginal area.  Process work has demonstrated the presence of underflows associated with many high discharge events during July, although there is seemingly not a direct relationship with underflow activity and daily temperatures (Lewis et al., 2002 in press).  Lake ice persists until at least mid-August and inhibits thermal stratification in the lake.  Discharge decreases in August concomitant with cooler temperatures and reduced ice melt.  Lake ice formation is delayed by persistent, strong winds, but probably sets in September, depending on storminess and ambient temperatures.
PARAGRAPH_XXO Sediments from the proximal basin appear as clear couplets of coarser, carbonate-rich silt grading normally into darker clay.  The sediments were studied in detail using petrographic thin sections and the rhythmites were counted and measured on three separate occasions using 600 dpi scans.  Given the strong seasonality of the sediment delivery to Bear Lake and the consistency of the sedimentary structures, we interpret these couplets to be varves.  A profile of 210Pb activity did not provide a consistent means for independently dating the couplets, due to low levels of 210Pb and highly variable sedimentation rates (inferred from couplet thickness).  Therefore, although we cannot independently verify the presence of varves, the primary evidence (sedimentology) gives us confidence that the proximal sediments in Bear Lake are varved.
PARAGRAPH_XXO Cores retrieved from two sites in the basin (Cores 18 and 19) show similar sedimentary structures and varve sequences which can be correlated on the basis of structure and thickness changes.  Average thickness of the varves is 4.6 mm but is highly variable.  Relatively thin varves (<3 mm) are common and contain silt and clay in nearly equal proportions.  Thicker varves contain graded units of carbonate-rich silt and in some cases, exceed 50 mm thickness. Compared to the more proximal site (core 18, 100 m depth), core 19 (88 m depth) contains fewer thick varves.  Additionally, the distal core contains sections of poorly laminated to massive clay zones varying from a 3-20 millimetres thick.  Cross-dating between the two cores reveals that the poorly laminated/massive sections represent years with consistently low accumulation rates in the proximal core and effectively represent short gaps in the distal core, lasting 3-25 years.  The gaps can be bridged with the continuous record from the proximal core, allowing cross-dating both cores to 1308 AD.  The proximal core continues to 1250 AD and terminates at the core bottom.
PARAGRAPH_XXO Based on observations of underflows during the summer of 1999 (Lewis et al., 2002 in press), the thick carbonate-rich silt units found in the cores are likely produced by the same mechanism and represent sporadic deposition from turbid underflows associated with meltwater production from the ice cap.  Although we cannot quantitatively constrain the meteorological conditions that produce these events (to say a daily temperature), they are clearly a product of high meltwater production and suspended sediment entrainment.  We can further constrain the intensity of these underflows by their presence or absence in the distal core.  Periods when sedimentation was dominated by homopycnal flow produce thin proximal varves and vaguely layered to massive sediments in the distal areas.  The presence or absence of underflow deposits in the varves indicates periods in the record without weather conditions suitable for generating underflows, and probably represent cooler years.  The most persistent underflow deposition occurred from 1900-1970 and to a lesser extent, during the 1300s and late 1700s.  Underflows were consistently infrequent during the 1800s and early 1400s and 1700s.  Overall, the 1920-1970s represent the highest sedimentation rates of the entire 750-year record and suggests that deposition has decreased substantially in the late 20th century.  Comparison with the melt record and d18O record from the Devon ice core shows many similarities between the two records, particularly during the 20th century.
PARAGRAPH_XXO Comparison of varve thickness with meteorological records from Pond Inlet and Resolute shows a consistent maximum correlation with mean September temperatures (Pond Inlet 1977-88, r2= 0.445, p<0.07, n=12; Resolute 1951-80, r2= 0.237, p<0.10, n=30).  Strangely, the maximum correlation between the meteorological record and the Bear Lake varve thickness was during the last two weeks of September (r2=0.530, p< 0.04, n=12).  These results suggest that the period of lake ice formation is the most important control over sedimentation rates and we suspect that wave-induced erosion and slumping from the delta front during the open-water period could generate a significant proportion of the interannual variance in recent sedimentation rates.  By contrast, the early Pond Inlet weather record (1923-1960 with frequent gaps) shows a modest correlation with July temperatures (r2=0.155, n=30) and essentially no correlation with September temperatures (r2= 0.050, n=30).  This latter period covers the highest sedimentation rates of the last 750 years and may indicate an increased importance of melt-generated underflow activity.  Regardless of the specific mechanism involved, both indicate that sedimentation is positively correlated with some aspect of summer temperature and hence, the overall correlation to the ice core record.
PARAGRAPH_XXO 	
PARAGRAPH_XXO The results from the Bear Lake varve record underscore the importance of process work for interpreting the hydroclimatic record contained in the sediments, and demonstrate that the linkages between sedimentation and hydroclimatic processes may change with time.  While one or several years of this labour-intensive work may be all that is tractable, it is clear that, like the meteorological record, a short-term view of environmental processes can generate misconceptions regarding the linkages between sedimentation processes and catchment controls.

REFERENCE_XXO Alt, B.T., Koerner, R.M., Fisher, D.A. and Bourgeois, J.C., 1985. Arctic climate during the Franklin era, as deduced from ice cores. In: P.D. Sutherland (Editor), The Franklin Era in Canadian Arctic History 1845-1859. Archaeological Survey of Canada Paper no. 131, pp. 69-92.
REFERENCE_XXO Hughen, K.A., Overpeck, J.T. and Anderson, R.F., 2000. Recent warming in a 500-year palaeotemperature record from varved sediments, Upper Soper Lake, Baffin Island, Canada.  The Holocene, 10: 9-19.
REFERENCE_XXO Koerner, R.M. and Fisher, D.A., 1990. A record of Holocene summer climate from a Canadian high-Arctic ice core. Nature, 343: 630-631.
REFERENCE_XXO Lamoureux, S., 2000. Five centuries of interannual sediment yield and rainfall-induced erosion in the Canadian High Arctic recorded in lacustrine varves. Water Resources Research, 36(1): 309-318.
REFERENCE_XXO Lewis, T., R. Gilbert and S.F. Lamoureux, 2002 in press.  Spatial and temporal changes in sedimentary processes at proglacial Bear Lake, Devon Island, Nunavut.  Arctic, Antarctic and Alpine Research.
REFERENCE_XXO Overpeck, J., K. Hughen, D. Hardy, R. Bradley, R. Case, M. Douglas, B. Finney, K. Gajewski, G. Jacoby, A. Jennings, S. Lamoureux, G. MacDonald, J. Moore, M. Retelle, S. Smith, A. Wolfe and G. Zielinski, 1997.  Arctic environmental change of the last four centuries, Science, 278: 1253-1256.

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE LATE WEICHSELIAN ICE SHEET ALONG WESTERN SVALBARD: ICE FREE AREAS EXISTED

AUTHORS_XXO LANDVIK, JON Y. (1); Brook, Edward J. (2); Gualtieri, Lyn (3); Raisbeck, Grant (4); Salvigsen, Otto (5); Yiou, FranÉoise (6)

AUTHOR_1_XXO (1) Agricultural University of Norway, Norway; jon.landvik@nlh.no
AUTHOR_2_XXO (2) Washington State University, USA; brook@vancouver.wsu.edu 
AUTHOR_3_XXO (3) University of Washington, USA; lyn4@u.washington.edu
AUTHOR_4_XXO (4) Centre de SpectromÅtrie NuclÅaire et de SpectromÅtrie de Masse, France; raisbeck@csn-mail.in2p3.fr
AUTHOR_5_XXO (5) University of Oslo, Norway; otto.salvigsen@geografi.uio.no
AUTHOR_6_XXO (6) Centre de SpectromÅtrie NuclÅaire et de SpectromÅtrie de Masse, France; yiou@csnsm.in2p3.fr

PARAGRAPH_1_XXO Present reconstructions suggest that glacier ice along the northwest sector of the last Svalbard/Barents ice sheet extended to the shelf edge west of Spitsbergen. This has been shown by the westward distribution of Late Weichselian glacial diamictons mapped by sediment cores and seismic lines. In contrast to the offshore evidence, previous interpretations of the terrestrial stratigraphic and geomorphologic records at several sites have suggested more limited ice extent.
PARAGRAPH_XXO The new field studies reported here have focused on the vertical extent of the Late Weichselian ice sheet along the mountains of western Svalbard. Key areas on NW Svalbard have been revisited in order to map out the boundaries between glaciated and non-glaciated surfaces, and several vertical transects of the mountains along the west coast of Svalbard are now being investigated. In all the study areas, glacial erratics from mainland Spitsbergen are frequent, and suggest at least one former extensive glaciation of the whole area.
PARAGRAPH_XXO Amsterdamøya off NW Spitsbergen is situated only 20 km from the shelf break. The higher parts of the islands (300-500 m a.s.l.) are covered with blockfields previously interpreted to have been associated with nunataks during the Late Weichselian. Our studies show that erratic boulders deriving from Spitsbergen were deposited by glacier ice after the formation of the blockfields. The last ice advance over the higher ground occurred at ca 70 ka or earlier, according to 10Be exposure age dates on these erratics. The lower ground (<100 m a.s.l.) is characterised by glacially sculptured bedrock and fresh looking moraines. Based on late glacial ages obtained from bedrock and erratics in the moraines, we conclude that the fjords and sounds were glaciated during the Late Weichselian. A late Weichselian glaciation of the lower ground is also supported by stratigraphic evidence from sediment sections close to sea level. Mollusc shells found below a till bed with Spitsbergen erratics yielded a radiocarbon age of 43 ka. The young finite age is supported by low aIle/Ile amino acid ratios.
PARAGRAPH_XXO Our studies confirm that nunataks have existed on the west coast of Svalbard during the Late Weichselian, and that the ice sheet was thinner than during preceding Weichselian stadials. We also conclude that the blockfields in NW Spitsbergen have survived extensive glaciation, and that the may be of a preglacial age.

INSERT_PAGE_BREAK_HERE
TITLE_XXO HOLOCENE CLIMATIC CHANGE AND TREE-LINE RESPONSE IN LEIRDALEN, WESTERN JOTUNHEIMEN, SOUTH CENTRAL NORWAY

AUTHORS_XXO LANGDON, CATHERINE T. (1); Dumayne-Peaty, Lisa (2); Matthews, John A. (3)

AUTHOR_1_XXO (1) University of Exeter; c.t.langdon@exeter.ac.uk
AUTHOR_2_XXO (2) University of Birmingham
AUTHOR_3_XXO (3) university of Wales, Swansea

PARAGRAPH_1_XXO The tree-line is a sensitive ecotone that consists of trees that grow at their climatic limit and previous studies have shown that the tree-line has responded substantially to climatic change (e.g. Aas and Faarlund, 1996; Gunnarsdottir, 1996; Torske, 1996).  There are, however several debates surrounding the exact effect of climatic change on the tree-line.  For example, there is contention over whether an early Holocene sub-alpine birch belt occurred above the pine tree-line (Aas and Faarlund, 1988, 1996), whether it established as the result of a mid-Holocene climatic deterioration (Gunnarsdottir, 1996) or later Holocene climatic instability (Kullman, 1981).  Furthermore, recent palaeoenvironmental and palaeoecological research, notably in Scandinavia, has focused on the nature and extent of the Finse event (a cooler, wetter period c. 8,200 cal. years B.P. that caused glaciers to advance (Nesje and Dahl, 2001; Tinner and Lotter, 2001) and its effect on vegetation.  The LIA is also an important event in Scandinavian climatic history but there is little palynological evidence for its effect on vegetation due to the deposition of predominately inorganic sediments and difficulties in distinguishing the effect of climatic change from the effects of human activity.  
PARAGRAPH_XXO Traditionally megafossil evidence has been used to elucidate the position of past tree-lines but this evidence is often spatially and temporally discontinuous, and therefore pollen and macrofossil studies can supplement information based on past tree-lines from megafossil data.  As such, this poster presents the results of pollen analysis of a small mire to provide evidence for long term changes in forest composition and extent at and around the present day altitudinal tree-line in the Leirdalen valley, south central Norway.  The results presented are part of a wider study carried out into tree-line fluctuations in the area (Barnett et al., 2001).  The palynological data indicates that following deglaciation c. 10115 cal. years B.P., dense pine forest migrated into the area replacing vegetation that was dominated formerly by birch.  It is probable that the pine forest-limit subsequently increased in altitude significantly in response to a warmer climate with average summer temperatures higher than at present.  This climatic optimum is thought to have been interrupted by a climatic deterioration dated to c. 8,380 cal. years B.P. (the Finse event) that caused the woodland around the site to diminish and allowed the emergence of a light demanding vegetation assemblage.  A sudden shift from dense pine forest to birch woodland with pine and alder in conjunction with the development of a sub-alpine birch belt is postulated to have occurred c. 6870 cal. years B.P.  Further deterioration of climate with neoglacial episodes led to the suppression of the tree-line c. 3930 cal. years B.P.  However, after c. 1900 cal. years B.P. the trends in the pollen profiles imply that there was a retreat in the tree-line due to the Little Ice Age and/or human impact on the landscape.
PARAGRAPH_XXO The study has been refined through the collection of modern pollen data derived from Tauber traps in order to create a modern pollen analogue with which to relate the fossil pollen assemblages.  Furthermore, models developed through the NorFA-POLLANDCAL network (Gaillard et al. 2002) have been used to predict the quantitative relationship between suggested landscape scenarios at the tree-line and pollen percentages.  Through the use of these techniques it has also been possible to consider the spatial scale of the landscapes represented by pollen deposited in the different sizes of sampling site used in this study.

REFERENCE_XXO Barnett, C., Dumayne-Peaty, L. and Matthews, J.A. (2001).  Holocene climatic change and tree-line response in Leirdalen, central Jotunheimen, south central Norway.  Review of Palaeobotany and Palynology. 117, 119-137.
REFERENCE_XXO Torske, N. (1996).  Holocene vegetation, climate and glacier histories in the Jostedalsbreen region, western Norway - palaeoecological interpretations from an alpine peat deposit. In: Frenzel, B. (ed), Holocene Treeline Oscillations, Dendrochronology and Palaeoclimate.  Vol 20 European Palaeoclimate and Man, 13.  Gustav Fischer Verlag, Stuttgart. 215-232.
REFERENCE_XXO Gunnarsdottir, H. (1996).  Holocene vegetation history and forest-limit fluctuations in Smadalen, eastern Jotunheimen, south Norway.  In: Frenzel, B. (ed), Holocene Treeline Oscillations, Dendrochronology and Palaeoclimate.  Vol 20 European Palaeoclimate and Man, 13.  Gustav Fischer Verlag, Stuttgart. 233-255.
REFERENCE_XXO Aas, B. and Faarlund, T. (1996).  The present and Holocene sub-alpine Betula spp. Belt in Norway.  In: Frenzel, B. (ed), Holocene Treeline Oscillations, Dendrochronology and Palaeoclimate.  Vol 20 European Palaeoclimate and Man, 13.  Gustav Fischer Verlag, Stuttgart. 19-42.
REFERENCE_XXO Nesje, A. and Dahl, S.-O. (2001).  The Greenland 8200 cal. Yr BP event detected in loss-on-ignition profiles in Norwegian lacustrine sediment sequences.  Journal of Quaternary Science, 16 (2), 155-166.
REFERENCE_XXO Tinner, W. and Lotter, A.F. (2001). Central European vegetation response to abrupt climate change at 8.2 ka. Geology, 29 (6), 551-554.
REFERENCE_XXO Gaillard, M.-J. and POLLANDCAL members (2002).  The pollen/landscape calibration (POLLANDCAL) network of the Nordic council of Ministers (NorFA). 

INSERT_PAGE_BREAK_HERE
TITLE_XXO ICELANDIC CHIRONOMIDS: A HOLOCENE ENVIRONMENTAL RECONSTRUCTION FROM NW ICELAND

AUTHORS_XXO LANGDON, PETE G. (1); Caseldine, Chris J. (2); Geirsdottir, Aslaug (3)

AUTHOR_1_XXO (1) University of Exeter; p.g.langdon@ex.ac.uk
AUTHOR_2_XXO (2) University of Exeter; c.j.caseldine@ex.ac.uk
AUTHOR_3_XXO (3) University of Iceland; age@hi.is

PARAGRAPH_1_XXO Chironomids have been shown to respond rapidly to past changes in temperature (e.g. Walker et al. 1991; Lotter et al. 1999; Brooks and Birks 2000; 2001) which make them an attractive palaeoclimatological proxy, particularly as they can be found in abundance in climatically marginal or severe environments.  The construction of transfer functions, based on the development of a modern day training set from which individual taxon optima can be deduced, has allowed the quantitative reconstruction of temperatures using chironomids.  This is particularly attractive for researchers working on Icelandic terrestrial sediments as the vast majority of palaeoclimatic reconstructions from these sites around the Nearctic relies on evidence from pollen spectra (Miller et al., 2001) which remains difficult to quantify in terms of thermal limits.
PARAGRAPH_XXO Studies on Icelandic chironomids have been largely restricted to ecological studies in freshwater ecosystems (e.g. Jónasson 1979, 1992; Lindegaard, 1992; Garðarsson et al. 1995) with little work have been undertaken on subfossil chironomids.  One profile is known to have been examined from Mývatn (Einarsson and Haflidason 1988), which is a eutrophic lake fed mainly by spring water (occasionally with temperatures of up to 30°C), although only a few chironomid taxa were documented in any detail. Mývatn may therefore not be the best place to look for a thermal response from chironomid assemblages - a more suitable location was needed where other proxy climate indicators could be developed to facilitate a comparison with a chironomid reconstruction.  
PARAGRAPH_XXO High resolution marine cores have recently been obtained from nearshore fjord deposits in Ísafjarðardjúp (NW Iceland) which span Holocene timescales (e.g. Andrew et al. 2000; 2001). Lakes in the NW region have also been sampled recently with sedimentological and palynological analyses suggesting that the region has been sensitive to climatic changes since deglaciation. NW Iceland was therefore selected as a key area from which to analyse Holocene chironomid faunas due to the presence of these marine and terrestrial data as well as the lack of geothermal activity within the region.
PARAGRAPH_XXO Initial examination of Holocene chironomid assemblages from a site in NW Iceland at Efstadalsvatn (65°55'N 21°40W) has provided an abundance of chironomid remains and application of the Norwegian chironomid-inferred temperature transfer function to the data (S.Brooks and J.Birks, pers. comm.) has produced the first terrestrially based temperature reconstruction for Iceland.  The chironomid-inferred temperature reconstruction suggests a rise from ca. 40C at 11,000 cal. BP to ca. 100C by 9500 cal. BP although this is not without a number of oscillations, and the basic pattern is comparable with Greenland ice core reconstructions.  The chironomid based reconstruction throughout the rest of the Holocene (the record terminates around 4000 cal. BP) fluctuates between 8.50C and 110C.  The taxonomy of species is in general comparable to NW Europe and has therefore been based on the European fauna and the Norwegian transfer function could thus be used for the Icelandic data.  There are, however, some important differences in the taxonomy and until an Icelandic training set is derived key issues relating to chironomid temperature reconstructions from Icelandic lake sediments cannot be resolved.
PARAGRAPH_XXO Recent research suggests that at least 33 chironomid genera can be found in Iceland, containing 75 species, with the fauna tending to resemble the European fauna (Hrafnsdóttir et al. 2000).  The study of Holocene sediments from a variety of Icelandic non-thermal oligotrophic lakes would thus allow important comparisons, not only in terms of the Icelandic Holocene fauna, but also by comparing the results with the Norwegian and North American faunas.  Current investigations have revealed subfossil chironomids which have not been recorded in the modern fauna to date, hence the need to conduct extensive surveys of the lake surface sediments from the region as well as subfossil analyses.  Collaborative research is currently underway with Icelandic chironomid experts to resolve some of the issues between the modern and subfossil assemblages.
PARAGRAPH_XXO What is clearly now needed is the creation of a modern day Icelandic chironomid training set in order to develop a chironomid-inferred temperature transfer function for the region.  The NW has been selected as a key region due to its lack of geothermal activity and abundance of accessible lakes.  Once a model has been developed in the NW, chironomid faunas from geothermal lakes can be sampled and then compared with the model output in order to ascertain the effect of water temperature on the communities.
PARAGRAPH_XXO Over 30 lakes have been surveyed and found to be suitable for developing a modern day chironomid training set for NW Iceland (Figure 1).  The littoral region of some of the lakes have been sampled and some initial analysis undertaken.  The lakes surveyed were mainly in the NW peninsula, but also extended west towards the Snæfellsnes peninsula, including the region around Stykkishólmur, and covered an altitudinal range from 0-500 metres (Figure 1).   Plenty of other lakes were also observed within the region, which would provide over 100 lakes suitable for the development of a modern day chironomid training set.
PARAGRAPH_XXO A number of lakes were surveyed from the NW peninsula in order to provide a detailed sedimentary record and ultimately a high resolution palaeoclimatic reconstruction.  Gjögurvatn, in the Strandir area provides the best opportunity to correlate land and sea studies, and Laugarbólsvatn/Efstadalsvatn, two connected lakes, offer the best possibility of a quantitative reconstruction of July temperatures over the past 10 ka from changes in chironomid assemblages. Sedimentological and palynological analyses will also be undertaken on these lakes in collaboration with The University of Iceland and INSTAAR.  The combined results from these lakes will provide a unique palaeoclimatic record for the entire Holocene, with the possibility of extracting the anthropogenic effect from the natural forces on climate in the late Holocene.

REFERENCE_XXO Andrews, J. T. and 10 others (2000). The N and W Iceland Shelf: insights into Last Glacial Maximum ice extent and deglaciation based on acoustic stratigraphy and basal radiocarbon AMS dates. Quaternary Science Reviews, 19, 619-631.
REFERENCE_XXO Andrews, J.T., Caseldine, C.J., Weiner, N. and Hatton, J.M. (2001). Causes of Late Holocene (ca. 4ka) marine and terrestrial environmental change in ReykjarfjÑrÂur, N.Iceland: climate and/or settlement? Journal of Quaternary Science, 16, 133-143.
REFERENCE_XXO Brooks, S.J. and Birks, H.J.B. (2000). Chironomid-inferred late-glacial and early-Holocene mean July air temperatures for Kr�kenes Lake, western Norway. Journal of Paleolimnology, 23, 77-89.
REFERENCE_XXO Brooks, S.J. and Birks, H.J.B. (2001). Chironomid-inferred Late-glacial air temperatures at Whitrig Bog, southeast Scotland. Journal of Quaternary Science, 15, 759-764.
REFERENCE_XXO Einarsson, A. and Haflidason, H. (1988). Predictive paleolimnology: effects of sediment dredging in Lake Mövatn, Iceland. Verh. Internat. Verein. Limnol., 23, 860-869.
REFERENCE_XXO GarÂarsson, A., Ýlafsson, J.S., Hrafnsdœttir, Th., G›slason, G.M. and Einarsson, ä. (1995). Monitoring chironomid numbers at Mövatn, Iceland: the first sixteen years, pp. 141-154 in Cranston, P.S. (ed) Chironomids: From genes to ecosystems. Melbourne: CSIRO.
REFERENCE_XXO Hrafnsdœttir, T., Ýlafsson, J.S. and Ýlafsson, E. (2000). Occurrence and distribution of Chironomidae in Iceland, pp. 517-523 in Hoffrichter, O. (ed) Late 20th Century Research on Chironomidae: an Anthology from the 13th International Symposium on Chironomidae. Shaker Verlag, Aachen.
REFERENCE_XXO Jonasson, P.M. (1979). Ecology of eutrophic, subarctic Lake Myvatn and River Laxa. Oikos, 32, 1-308.
REFERENCE_XXO Jonasson, P.M. (1992). The ecosystem of Thingvallavatn: a synthesis. Oikos, 64, 405-434.
REFERENCE_XXO Lindegaard, C. (1992). Zoobenthos ecology of Thingvallavatn: vertical distribution, abundance, population dynamics and production. Oikos, 64, 257-304.
REFERENCE_XXO Lotter, A.F., Walker, I.R., Brooks, S.J. and Hofmann, W. (1999). An intercontinental comparison of chironomid palaeotemperature inference models: Europe vs North America. Quaternary Science Reviews, 18, 717-735.
REFERENCE_XXO Miller, G. and CAPE project memebers (2001). Holocene paleoclimate data from the Arctic: testing models of global climate change. Quaternary Science Reviews, 20, 1275-1287.
REFERENCE_XXO Walker, I.R., Smol, J.P., Engstrom, D.R. and Birks, H.J.B. (1991). An assessment of Chironomidae as quantitative indicators of past climatic change. Canadian Journal of Fisheries and Aquatic Science, 48, 975-987.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/5-1.jpg

CAPTION_XXO Fig 1.  Detailed map of NW Iceland showing the location of recently sampled marine cores, surveyed lakes, sites with sediment cores currently being analysed, and proposed coring sites.

INSERT_PAGE_BREAK_HERE
TITLE_XXO MICROBLADE MORPHOLOGY AND TRACE ELEMENT ANALYSIS:  AN EXAMINATION OF OBSIDIAN ARTIFACTS FROM ARCHAEOLOGICAL SITE 49-PET-408

AUTHORS_XXO LEE, CRAIG M.

AUTHOR_1_XXO Dept. of Anthropology & INSTAAR, University of Colorado-Boulder; craig.lee@colorado.edu

PARAGRAPH_1_XXO 49-PET-408 (On Your Knees Cave) is an archeological and paleontological site located on Prince of Wales Island in Southeast Alaska (Dixon et al. 1997).  49-PET-408 was used periodically by humans between c. 10,300 14C BP and c. 1,200 14C BP with the most extensive occupations occurring between c. 9,300 and 7,500 14C BP (Dixon 2002).
PARAGRAPH_XXO Obsidian artifacts from 49-PET-408 are made from non-local raw materials requiring long distance transportation and/or trade to access.  Visually identifiable characteristics of obsidian artifacts, such as color and translucency, have been correlated through trace element analysis to specific source areas in British Columbia (Mount Edziza, circa 200 air-miles distant) and southeastern Alaska (Sumez Island, circa 65 air-miles distant)(Lee 2001).  Metric attributes of the obsidian microblades indicate specific morphologies (i.e., width, thickness, etc.) vary between artifacts manufactured from the two sources.  Although these differences could result from slight variations in production occurring between different occupations or even differences between individual flintknappers, they might also reflect varying degrees of reduction owing to the obsidian sources’ relative distances from 49-PET-408.  A recent comparison of 31 quartz crystal microblades from 49-PET-408 with the 92 obsidian microblades examined previously by Lee (2001) suggests that the observed differences in microblade morphology at 49-PET-408 are a result of raw material variation inherent in the two sources of obsidian and the quartz crystals. 
PARAGRAPH_XXO Analysts interested in microblade technology frequently group measurements drawn from a given site together, regardless of material type, to form a composite “profile” of the morphology of a given microblade assemblage.  However, if raw material variation significantly affects microblade morphology and assemblages containing different proportions of microblades made from various material types were compared, any patterning that results from human behavior, such as variation in manufacturing techniques, might be rendered invisible.  Based on the intra-assemblage variation present at 49-PET-408, future inter-assemblage examinations of microblade morphology need to address the effects of raw material variation on microblade form.  

REFERENCE_XXO Dixon, E.J.
REFERENCE_XXO 2002  49-PET-408 (On Your Knees Cave), An Overview.  Published Abstracts, 67th Annual Meeting of the Society of American Archaeology, Denver.  
REFERENCE_XXO Dixon, E.J., T.H. Heaton, T.E. Fifield, T.D. Hamilton, D.E. Putnam, and F. Grady
REFERENCE_XXO 1997  Late Quaternary Regional Geoarchaeology of Southeast Alaska Karst: A Progress Report. Geoarchaeology 12(6):689-712.
REFERENCE_XXO Lee, C.M.
REFERENCE_XXO 2001  Microblade Morphology and Trace Element Analysis:  An examination of Obsidian Artifacts from Archaeological Site 49-PET-408.  Unpublished Masteràs thesis, Department of Anthropology, University of Wyoming, Laramie.

INSERT_PAGE_BREAK_HERE
TITLE_XXO FRESHWATER DIATOM PALEOECOLOGY OF BANKS ISLAND, N.W.T., CANADIAN HIGH ARCTIC

AUTHORS_XXO LIM, DARLENE SS. (1); Douglas, Marianne SV. (2); Smol, John P. (3)

AUTHOR_1_XXO (1) University of Toronto; lim@geology.utoronto.ca
AUTHOR_2_XXO (2) University of Toronto; msvd@geology.utoronto.ca
AUTHOR_3_XXO (3) Queen's University; SmolJ@BIOLOGY.QueensU.Ca

PARAGRAPH_1_XXO The Canadian High Arctic is a distinct region of our planet in the way that it supports like, responds to shifts in the climate, and affects the environments of the rest of the globe.  With the need to better understand the far reaching effects of high arctic climate change, comes the demand for continued immediate and long-term monitoring of the High Arctic.  However, this is a difficult region to monitor on a frequent basis due to financial and logistical constraints (Douglas & Smol 1993), and relatively little ecological baseline data exists for many areas throughout the High Arctic.  The situation is slowly being rectified through limnological and paleolimnological investigations that allow for the acquisition of both baseline and historical limnic data from the myriad of lakes (depth>2m) and ponds (depth<2m) that dot the landscape of the High Arctic.  
PARAGRAPH_XXO Lake and pond sediments preserve many biological indicators that can serve as proxy indicators of past environmental changes.  More specifically, in the oligotrophic lakes and ponds of the High Arctic, diatoms (class Bacillariophyceae) often are a significant part of the algal community (Douglas & Smol 1999).  Their fossilized siliceous remains are usually well preserved in stratigraphic deposits, and are used as bioindicators in our investigations of past physical and chemical limnic conditions.  
PARAGRAPH_XXO In the High Arctic, surface sediment samples (~ top 1cm) represent an integrated sample of diatom communities, both spatially (i.e. from various habitats) and temporally (i.e. last few years of deposition).  A quantitative relationship between the dominant surface sediment diatom assemblages and present-day limnic properties can be established in order to produce environmental reconstruction models.  This study focuses on the development of a calibration set for Banks Island, NWT, Canadian High Arctic, and the application of this environmental reconstruction model to a 34cm core taken from lake BK-AH (73º35.57N, 119º35.01W) on Banks Island, which is the southwestern most island of the Canadian Arctic Archipelago.  The calibration set construction is currently in progress, however all results to date, including general trends driving species variance amongst the sampled sites, are described in this poster presentation.  The completed calibration set will be applied to the core findings from both sites.  Core stratigraphies are also presented in this poster.
PARAGRAPH_XXO A total of forty-six lakes and ponds were sampled on foot and via helicopter throughout Banks Island over a three and a half week period.  These sites were selected in order to cover as wide an environmental gradient as possible (e.g. proximity to sea, altitude, size, drainage characteristics, etc.).  While all sites were sampled for both abiotic and biotic limnological components, only 36 sites of the entire sample set were appropriate for surface sediment diatom collections, and are herein described and analyzed in this poster presentation.  Of this subset of sites, nine were lakes, and the remaining 27 were ponds (maximum depth <2m).  Although over 250 diatom species were identified from the surface sediments, only those taxa that had a relative abundance of ( 1% in a minimum of three sites were included in the ordination analysis/calibration set construction.  The dominant diatom species identified were pennate and benthic, which is typical for high latitude oligotrophic lakes and ponds.  Overall, compared to other previously investigated high arctic islands such as Bathurst Island (Lim et al. 2001), the limnology and diatom community composition of the sampled sites on Banks Island are much more diverse, most likely as a result of the varied elevation, vegetation and surficial material across the island.  Preliminary Canonical Correspondence Analysis (CCA) results indicate that the first two axes of the ordination captured 28.1% of the cumulative diatom-environment relation, however this value is expected to increase as further analyses are conducted to identify the key limnological drivers for the diatom species distribution.  Overall, it appears that Axis 1 of the CCA is most strongly driven by temperature (TEMP), conductivity (COND), DOC/DIC and chlorophyll a (uncorrected) (CHLA-U) concentrations.  Axis 2 represents an ionic gradient, driven primarily by Al+, Fe3+ and Zn+.  These CCA data will comprise the foundation of the calibration set construction for Banks Island.  
PARAGRAPH_XXO Core findings from site BK-AH show a shift in from greater diatom diversity between 0-7cm to a dominance of Fragilaria brevistriata, Fragilaria pinnata, and Fragilaria construens throughout the remainder of the core (7-34cm).  Although all three Fragilaria species are present throughout the core, their presence significantly (R=0.84) increases downcore, while overall diatom species diversity decreases from top to bottom.  Douglas et al. (1994) and Lim et al. (2001) identified F. pinnata and F. construens as being associated with deeper, colder, more oligotrophic sites, thereby indicating that a potential shift in nutrient and temperature regimes from less to more nutrient rich conditions relative to its past state may have occurred in the Banks Island lake.  This hypothesis will be refined once the calibration set is constructed and applied to the core stratigraphy.  
PARAGRAPH_XXO Next steps include completing the calibration set and applying it downcore, as well as comparing these findings to additional cores taken from two other sites on Banks Island, and other high arctic sites such as Cape Herschel, Ellesmere Island, Nunavut (Douglas et al. 1994), and the Grinnell Peninsula on Devon Island, Nunavut (Lim et al. in progress).

INSERT_PAGE_BREAK_HERE
TITLE_XXO RECONSTRUCTING THE LATE HOLOCENE (LAST 3000 YEARS) ICE-JAM FLOOD HISTORY OF THE MIDDLE YUKON RIVER -  DAWSON CITY, YUKON TO CIRCLE, ALASKA

AUTHORS_XXO LIVINGSTON, JOANNE M. (1); Froese, Duane G. (2); Smith, Derald G. (3)

AUTHOR_1_XXO (1) University of Calgary; jmliving@ucalgary.ca
AUTHOR_2_XXO (2) Simon Fraser University; dfroese@sfu.ca
AUTHOR_3_XXO (3) University of Calgary; dgsmit@ucalgary.ca

PARAGRAPH_1_XXO Along northern interior continental rivers, the formation of ice-jams and their associated flooding is a common phenomenon.  Analyses of extreme stage jams at Dawson City, Yukon, for the last century indicates that all overbank flood events have been ice-jam related (Figure 1).  Summer storms and spring freshet events have no oral or historic record of overbank floods. By augmenting the historic hydrometric data with pre-historic evidence from ice-jam floods, it is possible to extend the flood history of this river to at least 3000 years B.P.
PARAGRAPH_XXO This study presents a review of historic ice-jam flooding of the Yukon River (Dawson City and Fortymile, Yukon and Slavens Roadhouse, Alaska - Figure 2) and a new methodology to reconstruct the pre-historic flood record from sedimentary evidence (Figure 3) preserved in channel overbank floodplain deposits.  This method is based on the assumption that identifiable sand-silt couplets separated by organic layers represent large magnitude-duration, low frequency ice-jam floods. Sequences of up to 100 flood beds have been recorded in overbank deposits at twenty-nine sections within the study area; three key sites were selected for detailed analysis.  Conventional and AMS radiocarbon dating of organic material between flood deposits are used to obtain a more accurate flood frequency from which to assess large flood recurrence intervals. In addition, the late Holocene White River Ash forms a prominent stratigraphic marker in seventeen of the sections.  At one exceptional site, tree collars of a mature white spruce bracket the eruption within about 30 years from counting tree rings separating the tree growth collars.  An AMS age on the upper tree collar is dated to 1700+/-40 B.P., providing a minimum age for the northern tephra lobe.  Finally, the possibility exists to examine the influence of known climate changes (e.g. Little Ice Age, Medieval Warm Period) on late Holocene ice-jam flood frequency. 

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/26-1.jpg

CAPTION_XXO Fig 1.  Figure 1: Plot showing that the maximum flood events of the last 50 years have been ice-jam related.  Consequently the major natural hazard along the river is from ice-jam events.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/26-2.jpg

CAPTION_XXO Fig 2.  Figure 2: Study sites along the Yukon River

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/26-3.jpg

CAPTION_XXO Fig 3.  Figure 3: Photograph and sketch of flood couplets preserved in the overbank environment.  The sand-silt units arguably represent rapid deposition from ice-jam flood events while the organic cap indicates a relatively long period of quiescence and stability between each event.

INSERT_PAGE_BREAK_HERE
TITLE_XXO DEGLACIATION OF HIGH-LATITUDE COASTAL BASIN REFLECTED IN THE EVOLUTION OF A FAN-DELTA SYSTEM

AUTHORS_XXO LOENNE, IDA (1); Nemec, Wojtek (2)

AUTHOR_1_XXO (1) The University Courses on Svalbard (UNIS), Norway; ida.lonne@unis.no
AUTHOR_2_XXO (2) University of Bergen, Norway; Wojtek.Nemec@geol.uib.no

PARAGRAPH_1_XXO Studies of the Holocene deglaciation of Svalbard, Norwegian Arctic, indicate that the receding ice masses retreat quickly from fjords, but commonly turn into isolated, cold-based stagnant glaciers in high-relief onshore areas, where they then melt very slowly. In the cold climate of polar desert, the glaciers and permafrost active layer release water during brief summer seasons, and this abundant ephemeral runoff leads to high sediment dynamics and erases glacial deposits from the landscape. The resulting colluvial and alluvial fans are dominated by watery debrisflows and streamflow processes and are disproportionally large and voluminous, relative to their small catchments and the region¡¯s meagre annual precipitation. 
PARAGRAPH_XXO At the present stage of post-Little Ice Age deglaciation, Svalbard abounds in such stagnant ice bodies, ranging from high plateau and cirque glaciers to valley glaciers, some with marine termini. The rate of their summer melting is greatly reduced by the surficial accumulation of rock debris that has melted out from the ice and locally avalanched from adjacent steep mountain slopes. The glaciers effectively evolve into ice-cored moraines, and continue to melt slowly until the debris cover attains the local thickness of the active layer (averaging ca. 1 m at present). Their complete disintegration occurs only when gravitational foundering or streamflow erosion of the debris cover exposes the ice core. In mountain-slope cirques, the ice-cored moraines become richly covered with debris and often evolve into rockglaciers, whereas on low-gradient topographic surfaces, the flowing meltwater winnows fine-grained debris, leaving a coarse gravelly pavement. The glacigenic debris, whether mixed with scree material or reworked by flowing water, inevitably loses its identity, which leads to a rapid vanishing of the sedimentary record of glaciation. 
PARAGRAPH_XXO The region¡¯s morphogenic response to the Holocene climatic changes and deglaciation, in terms of the meltwater runoff, sediment flux and relative sea-level change, appears to be particularly well reflected in the depositional history of coastal sedimentary systems. The importance of this proxy record is demonstrated by the present sedimentological and stratigraphic study of an alluvial-fan delta in Adventfjorden, central Spitsbergen. The fjord became ice-free around 9.9 ka BP, and the fan delta formed during the main phase of post-Weichselian deglaciation and evolved through further major changes later during the Holocene. This Gilbert-type fan delta, up to 25 m thick and heavily modified by sea waves, reached a plan-view radius in excess of 1 km and a surface area of 1.2 km2, although its high-relief coastal catchment, scoured in sandstone and shale bedrock, has a plan-view area of no more than 2.6 km2. The fan apex is at an altitude of ca. 100 m, and the fan¡¯s steep catchment, extending to the mountain top at 923 m, is apparently a deglaciated cirque, hosting a rockglacier today. 
PARAGRAPH_XXO The fan delta consists of four distinct chronological parts, or depositional units, representing the main successive phases of its Holocene evolution: 
PARAGRAPH_XXO 1.	The oldest part, composed chiefly of gravel and sand, constitutes the bulk of the fan delta and represents the phase of its maximum progradation. It consists of a foreset of steeply inclined subaqueous deposits (upper ¡Ü6 m thickness exposed), containing Mytilus edulis shells and overlain by a topset of coarse gravelly alluvium, up to 4 m thick. The fluvial topset has an uneven erosional base and pinches out in the medial part of the fan delta, dated to ca. 6.2 ka BP, where the foreset facies change from massflow-dominated into fully wave-worked. The latter facies account for the final 160-m advance of the fan-delta front and correspond to a decline in its mean progradation rate from 0.30 to 0.12 m/yr and eventually to 0.07 m/yr. The delta foreset in the medial to distal part is overlain by a downstepping unit of delta-front beach-ridge gravel, which replaces the foreset facies at the distal end by forming a relatively thick (>4 m), aggradational beach, estimated to be ca. 4.5 ka BP in age. The catchment¡¯s high yield of meltwater and sediment apparently declined around 6.2 ka BP, as the melting cirque glacier probably turned into a cold-based ice body and the Neoglacial stage commenced around 5 ka BP. However, the relative sea level kept falling (forced regression) and the fan-delta front continued to prograde, at a decreasing rate, by accumulating wave-worked sediment supplied by alongshore drift. The relative sea level began to rise around 4.5 ka BP, which marked the onset of a marine transgression. 
PARAGRAPH_XXO 2.	The subsequent depositional part of the fan delta is an overlying unit of the landward-accreted, gravelly foreset deposits of a transgressive spit, up to 2 m thick and climbing onto the fan-delta plain to an altitude of ca. 6 m. The rate of the relative sea-level rise thus finally exceeded the declining rate of the isostatic crustal uplift. A corresponding, wave-cut bedrock escarpment is recognizable at the same altitude along the coast lateral to the fan delta. 
PARAGRAPH_XXO 3.	The overlying surficial deposits indicate that the activity of the fluvial system subsequently increased markedly, leading to a normal (progradational) regression, while the relative sea-level rise declined. The fluvial system expanded and the fan delta prograded again, reaching a radius of ca.1 km, probably in response to the melting of the catchment¡¯s relic glacier, which turned into a creeping rockglacier. An associated, regressive delta-front beach has been dated to ca. 4.3 ka BP, which implies that the preceding transgression was relatively brief.
PARAGRAPH_XXO 4.	The meltwater discharge then declined and the fluvial system became restricted to the fan¡¯s low flank, where it has incised and remains active today, while the abandoned fan surface was subject to sheetwash processes and covered by tundra vegetation. The stagnation of the fan delta rendered it vulnerable to erosion by wave action, combined with a strong alongshore drift of sediment. As a result, the fan delta had been shallowly eroded, its shoreline retreated by the formation of a wave-cut escarpment (<10 m high), and its subaerial area was reduced to ca. 0.4 km2 (<0.6 km radius). Concurrently, modest progradation occurred in the fan¡¯s incising, modern sector, less than 200 m wide. The modern beach, at the foot of the shoreline escarpment, passes laterally into an associated spit complex sheltering an intertidal lagoon. The spit shoal receives abundant sediment by alongshore drift, which has resulted in shoreline progradation (normal regression) in this part of the fjord¡¯s coast. The runoff today is due to the melting of the catchment¡¯s active layer and snow patches, and the ephemeral streamflow erodes and redistributes slowly the coarse gravel delivered by contemporaneous debrisflows. In the fan-head area, there is also evidence of a modern accumulation of debris derived and spread beyond the active sector by sporadic snow avalanches.
PARAGRAPH_XXO The depositional architecture and dynamic stratigraphy of the fan-delta system thus reveals a valuable, high-resolution proxy record of the coastal region¡¯s deglaciation history and climatic changes.

INSERT_PAGE_BREAK_HERE
TITLE_XXO HOLOCENE ENVIRONMENTAL RECORDS FROM THE NE BARENTS SEA REGION: CLUES TO CLIMATE FORCING ON MULTI-CENTURY-TO-MILLENIAL TIMESCALES IN THE EURASIAN HIGH ARCTIC

AUTHORS_XXO LUBINSKI, DAVID J.

AUTHOR_1_XXO INSTAAR; david.lubinski@colorado.edu

PARAGRAPH_1_XXO Although recent reconstructions have greatly increased our knowledge of the spatial and temporal variability of Holocene Arctic climate change (eg., Overpeck et al., 1997; CAPE Project members, 2001), much work remains to understand the causes of that variability.  This study reviews marine and terrestrial Holocene paleoenvironmental data (published and unpublished) in the NE Barents Sea region, which provide important clues to the mix of forcing factors operating in the Eurasian high Arctic on multi-century-to-millennial timescales.  In particular, these data attest to the importance of changes in insolation, Atlantic inflow, eustatic sea level, glacial-isostatic uplift, and atmospheric circulation.  Additional factors may have influenced the Eurasian high Arctic but are not readily studied with existing data (e.g., Siberian river discharge, sea ice-albedo feedback, vegetation-albedo feedback on mainland Eurasia, residual ice sheets in arctic Canada, high frequency NAO forcing).  To better understand all of these factors, new data must be collected and carefully compared to other regions as well as to new climate model simulations.
PARAGRAPH_XXO   
PARAGRAPH_XXO The NE Barents Sea region is well situated to help increase our understanding of a host of Holocene forcing factors.  It is presently bisected by the summer sea-ice limit, making it specifically useful for studying changes in sea ice cover.  It also lies along a track of cyclonic activity that brings warm and moist North Atlantic air masses deep into the Eurasian Arctic during prolonged positive phases of the NAO (North Atlantic Oscillation), the strongest mode of North Atlantic climate variability.  This connection to the North Atlantic is demonstrated by periodic covariations between the NAO and a number of environmental measures in both the northern and southern Barents Sea (i.e., glacier mass balance, winter temperature, winter precipitation, sea surface temperature; e.g., Zeeberg, 2001).  Furthermore, the NE Barents Sea is strongly connected to the Arctic Ocean and the Russian mainland coast through ocean currents, including those that carry driftwood from rivers ranging from the Dvina (White Sea) to the Lena (Laptev Sea).
PARAGRAPH_XXO In the past decade, a number of terrestrial and marine paleoenvironmental records have been produced in the NE Barents Sea region. These records include those from Franz Josef Land and northern Novaya Zemlya as well as the adjacent NE Barents shelf and the deep St. Anna and Franz Victoria troughs.  The entire NE Barents region was glaciated during the Last Glacial Maximum out to the shelf edge.  Deglaciation probably began c. 15 14C ka in the outer marine troughs and was completed throughout the marine areas by c. 10 14C ka. 
PARAGRAPH_XXO A number of climate forcings - some interconnected - appear to have influenced the Holocene paleoenvironmental record from this region:
PARAGRAPH_XXO * Summer insolation. July insolation at 80N was 11% higher than present at 10 14C ka (48 watts/m2 higher), making it one of the largest anomalies for any latitude during the past 100,000 years. Since no solar radiation reached these high northern latitudes in winter, the seasonality of insolation was also higher. Both the seasonality and summer anomaly slowly decreased during the Holocene.  Many available proxies are sensitive to summer solar radiation as well as its influence on air temperature.  For example, glacier extent records from Franz Josef Land, northern Novaya Zemlya, and Svalbard show glaciers behind present limits soon after deglaciation, retraction until at least c. 4 14C ka, and a series of subsequent Neoglacial advances (e.g., Svendsen and Mangerud, 1997; Lubinski et al., 1999; Zeeberg, 2001).  Moreover, several marine proxies (dinoflagellate cysts, benthic foraminifera, Bowhead whalebones?) suggest less-than-present sea ice cover during the early Holocene.  This result is consistent with the much thinner and less extensive summer sea ice cover simulated by climate models using the early Holocene insolation anomaly (e.g. TEMPO, 1996). 
PARAGRAPH_XXO * Atlantic inflows. Records from the Nordic Seas and Svalbard show higher-than-present northward transports of Atlantic Water during the early Holocene (e.g., Salvigsen et al., 1992; Koc et al., 1993).  The extension of these transports into the subsurface of the Arctic Ocean was recently verified with NE Barents Sea records of foraminiferal species and isotopic data (Duplessy et al., 2001; Lubinski et al., 2001).   Although early Holocene Atlantic transports were high, they do not appear to have entered the channels of Franz Josef Land (Lubinski et al., 1998).  Recently published dinoflagellate cyst records from the SE Barents Sea suggest that smaller recurrent Atlantic water variations may occur on a 1-1.5 kyr timescale after 5 ka and possibly earlier  (Voronina et al 2001).  Variations on an even shorter timescale are indirectly suggested by a high resolution glacial marine record on Northern Novaya Zemlya spanning the past 800 years (Zeeberg, 2001).
PARAGRAPH_XXO * Eustatic sea level and glacial-isostatic uplift.  Ice sheet coverage of the NE Barents Sea resulted in glacial-isostatically induced deepening by up to 150 m, which probably influenced Atlantic Water flows into the northern Barents Sea (Lubinski et al, 2001).  Foraminiferal stable isotopes show that Atlantic water transiting the Barents Sea probably entered the Franz Victoria Trough from the south during the early Holocene, a path that is blocked today by a shallow sill.  Atlantic water flows to the NE Barents Sea may also have been influenced by bathymetric changes elsewhere in the Arctic (i.e. Nares Strait and other E. Canadian Arctic Channels, Bering Strait).  Lowered sea levels on the unglaciated shallow Kara Sea and Laptev Sea shelves during the early Holocene led to more northerly river mouths in the Kara Sea and may have disrupted the Laptev Sea polynya, an important sea-ice factory and formation of dense water on the shelf.  The dense water helps maintain the halocline/pycnocline in the central Arctic Ocean as well as the NE Barents Sea.  Reduced dense water formation during the early Holocene may have decreased hydrographic stability, allowing heat exchange between Atlantic intermediate water and the overlying fresher water layer (and reducing sea ice cover).
PARAGRAPH_XXO * Atmospheric circulation. The Iceland Low, the strongest synoptic feature influencing the NE Barents Sea, has changed its strength and position during the Holocene.  It appears to have been stronger and displaced to the north during the early Holocene due to high summer insolation (e.g., Harrison et al., 1992).  The effect of this change on the NE Barents Sea can be inferred from meteorological data and models of extreme modern climate states (Serreze et al, 1993; Rogers and Mosley-Thompson, 1995; Proshutinksy and Johnson, 1997). The studies imply increased storminess and advection of heat from fall through spring, and, possibly, during summer.  Wind and ocean circulation patterns were undoubtedly altered by the more easterly extension of the low pressure trough into the Eurasian Arctic.  A potential record of this extension is the paucity of driftwood in the NE Barents Sea until c. 7 14C ka (Lubinski, in prep).  Expected atmospheric pressure patterns would cause easterly winds near the Eurasian coasts and transport of much driftwood alongshore (where it could be trapped) rather than into the open sea.  Data constraining Holocene driftwood provenance after c. 7 14C ka (genera ratios) suggest at least two recurrent modes of transport and circulation.
PARAGRAPH_XXO There remain several important climate forcing factors for the NE Barents Sea which are not easily studied with existing data.   For example, discharge reconstructions for the large Russian Arctic rivers remain rare or controversial despite the influence of their large riverine freshwater fluxes on regional hydrography, sea ice cover, etc.  Also needing study are the long-distance effects of the residual Holocene ice sheets in arctic Canada and two important albedo feedbacks.  A strong sea ice-albedo feedback is especially important for the timing for fall freeze up while a vegetation-albedo feedback on mainland Eurasia may have a strong influence on spring sea ice conditions far offshore (e.g., Foley et al., 1994;TEMPO, 1996).
PARAGRAPH_XXO Future efforts to improve our understanding of climate forcing factors in the Eurasian high Arctic should focus both on data and simulations.  Particularly needed are data-based Arctic river discharge reconstructions and long, high resolution paleoenvironmental records.  The ice caps of Franz Josef Land and northern Novaya Zemlya have not been fully exploited and new long ice cores will be invaluable.  Paleoenvironmental studies of the last millennium in the NE Barents Sea (when the NAO signal is most easily detected) will also help improve interpretations of earlier portions of the Holocene.  Climate simulations should be run to refine our understanding of the mix of forcing factors and physical processes.  For example, there are no simulations of the effects of lowered sea level and subsequent flooding of the shallow unglaciated Russian shelves on the arctic pycnocline, sea ice, and circulation.  Similarly the influence of glacial isostasy on bathymetry and its impact on ocean circulation has seldom been modeled.
PARAGRAPH_XXO Acknowledgements:  This poster will show data from many sources including a number of collaborative projects that Lubinski has done and is doing with Leonid Polyak (Ohio State University), Steven Forman (Univ of Illinois at Chicago), Sergey Korsun (Shirshov Institute of Oceanology), Jaap Jan Zeeberg (Univ of Illinois at Chicago), Stein Johansen (Univ of Sciences and Technology, Trondheim), and Anne de Vernal (GEOTOP, Univ of Quebec at Montreal).  
PARAGRAPH_XXO References:  All references listed here (and more) will be detailed on the poster.

INSERT_PAGE_BREAK_HERE
TITLE_XXO AN INTEGRATED ASSESSMENT OF THE IMPACTS OF CLIMATE VARIABILITY ON THE ALASKAN NORTH SLOPE COASTAL REGION: PROJECT OVERVIEW

AUTHORS_XXO LYNCH, AMANDA H. (1); Brunner, Ronald D. (2); Curry, Judith A. (3); Maslanik, James A. (4)

AUTHOR_1_XXO (1) U. Colorado Boulder; manda@cires.colorado.edu
AUTHOR_2_XXO (2) U. Colorado Boulder
AUTHOR_3_XXO (3) U. Colorado Boulder
AUTHOR_4_XXO (4) U. Colorado Boulder

PARAGRAPH_1_XXO Warming of the arctic climate is having substantial impact on the Alaskan North Slope coastal region. Increasing amounts of open water in the arctic seas combined with rising sea level, thawing permafrost, and changing human geography are predicted to contribute to increased impacts of meteorological events with their attendant storm surge, flooding and erosion. This poster describes a project that is underway to understand, support and enhance the local decision-making process on the North Slope of Alaska in the face of increasing sea ice variability and extreme weather events.

INSERT_PAGE_BREAK_HERE
TITLE_XXO GLACIAL HISTORY, SURFACE EXPOSURE AGES, AND PALEOELA'S OF THE YUKON TANANA UPLAND: PRELIMINARY RESULTS

AUTHORS_XXO MANLEY, WILLIAM F. (1); Briner, Jason P. (2); Lubinski, David J. (3); Caffee, Marc W. (4)

AUTHOR_1_XXO (1) INSTAAR, Univ. of Colorado; William.Manley@colorado.edu
AUTHOR_2_XXO (2) INSTAAR, Univ. of Colorado; jason.briner@colorado.edu
AUTHOR_3_XXO (3) INSTAAR, Univ. of Colorado; David.Lubinski@colorado.edu
AUTHOR_4_XXO (4) PRIME Lab and Dept. of Physics, Purdue University; mcaffee@physics.purdue.edu

PARAGRAPH_1_XXO A combination of field-based research, cosmogenic 10Be and 26Al surface-exposure dating, and spatial analysis of former Equilibrium Line Altitudes (paleo-ELA's) is yielding new insights into the Pleistocene glacial and climate history of the Yukon Tanana Upland (YTU), eastern Alaska (Fig. 1).  Across this broad region of dispersed massifs, glaciers existed for at least five periods during the Pleistocene (Weber and Hamilton, 1984; Weber, 1986; cf. Hamilton, 1994).  The type locality for these first-order glacial events was established at a nested moraine and drift sequence in and near the Ramshorn Creek valley, central YTU (Weber, 1986).  From youngest to oldest, they were named the Ramshorn, Salcha, Eagle, Mt. Harper, and Charley River glaciations.
PARAGRAPH_XXO Field research during the summer of 2000 concentrated on sampling five granodiorite boulders from the stable crests of each of the four youngest terminal moraines at the type locality.  Boulder samples were also taken from three moraines in the Mt. Prindle area, in the northwestern YTU, but were not analyzed due to budget constraints.  Field research included measurements of moraine morphology and other assessments of relative age.
PARAGRAPH_XXO Sample preparation and Accelerator Mass Spectrometry (AMS) measurements over the following year yielded 23 cosmogenic exposure ages (for overview of the method and interpretations, see Gosse and Phillips, 2001).  Preparation was done at the University of Colorado Cosmogenic Isotope Laboratory following the procedure of Kohl and Nishiizumi (1992).  Isotopic ratio measurements were made by AMS at Lawrence Livermore National Laboratory.  We used 10Be and 26Al production rates of 5.1 and 31.1 atoms/g (Gosse and Stone, 2001).
PARAGRAPH_XXO Seven of the 16 analyzed boulders yielded both Al and Be ages, which agree closely (r2 = 0.98).  In addition to standard corrections for latitude, elevation, and shielding,  the ages have been model-corrected for erosion and snow cover.  Analytical errors average 4%.  Boulder ages were averaged to calculate a mean and standard deviation for each of the two youngest moraines (Table 1).  Each of the older moraines exhibits a scatter of boulder ages, as expected for moraine crests that have experienced significant morphologic degradation.  For these moraines, we more heavily weight the older boulder ages on each moraine (cf. Putkonen, 2001).
PARAGRAPH_XXO Previous age assessments were based on a suite of relative age data (morphologic preservation, soil development, clast weathering, number of moraines within a glaciation, and downvalley extent), correlation to other glaciated ranges in Alaska, and two radiocarbon dates:  a minimum age of 50 14C ka for the Mt. Harper glaciation (Weber and Ager, 1984), and a minimum age of 2.3 14C ka for the Ramshorn glaciation (Weber, 1986).
PARAGRAPH_XXO The new surface exposure dates are the basis for the following interpretations:
PARAGRAPH_XXO      1) The Salcha moraine represents the maximum glacier extent during the Late Wisconsin glaciation, consistent with previous assessments.
PARAGRAPH_XXO      2) However, the Ramshorn cirque moraine is older than previously believed, with an age statistically indistinguishable from the Late Wisconsin maximum.  Inheritance of cosmogenic isotopes in all four boulders is unlikely.  Most likely the Ramshorn moraine marks a late-glacial recessional position or readvance.
PARAGRAPH_XXO      3) The age of the Eagle moraine has been under debate, dependent on correlations to the Delta and Late Reid glaciations in the Alaska Range and Yukon Territory, respectively (cf. Berger et al., 1996; Westgate et al., 2001).  With one young outlier omitted, the cosmogenic ages range from 44 ka to 76 ka.  Based on these ages, rather than regional correlation, our preliminary assessment is that the Eagle moraine marks the maximum of an Early Wisconsin glaciation (s.l., OIS 4 or 5).
PARAGRAPH_XXO      4) The four boulder exposure ages for the Mt. Harper moraine display some scatter, with the oldest age, 190 ka, as the oldest to our knowledge for a cosmogenic age in Alaska.  Given the limits of the technique for moraines of this apparent age, we conservatively conclude that the Mt. Harper moraine is OIS 6 or older (i.e., pre-last interglacial).
PARAGRAPH_XXO      Thus, the first direct, quantitative age estimates for glaciation in the Yukon Tanana Upland provide a few surprises, and add fuel to the debate on the age (and spatial variability) of the penultimate glaciation in the region.
PARAGRAPH_XXO Glacier extents for the youngest three glacial periods were mapped in the field and from aerial photography, guided by previous mapping (Weber and Hamilton, 1984; Weber, 1986; Weber, unpub.).  The glacier extents are currently being analyzed in a Geographic Information System (GIS).  Preliminary ELA results for 32 Ramshorn, 79 Salcha, and 89 Eagle paleoglaciers will be presented at the workshop.

REFERENCE_XXO Berger, G. W., Peteet, T. L., Westgate, J. A., and Preece, S., 1996, Age of Sheep Creek tephra (Pleistocene) in central Alaska from thermoluminescence dating of bracketing loess: Quaternary Research, v. 45, p. 263-270.
REFERENCE_XXO Gosse, J. C., and Phillips, F. M., 2001, Terrestrial in situ cosmogenic nuclides: Theory and application: Quaternary Science Reviews, v. 20, p. 1475-1560.
REFERENCE_XXO Gosse, J. C., and Stone, J. O., 2001, Terrestrial cosmogenic nuclide methods passing milestones toward paleo-altimetry: Eos, Transactions of the American Geophysical Union, v. 82, p. 82, 86, 89.
REFERENCE_XXO Hamilton, T. D., 1994, Late Cenozoic glaciation of Alaska, in Plafker, G., and Berg, H. C., eds., The Geology of Alaska: The Geology of North America, v. G-1, Geological Society of America, p. 813-844. 
REFERENCE_XXO Kohl, C. P., and Nishiizumi, K., 1992, Chemical isolation of quartz for measurement of in-situ-produced cosmogenic nuclides: Geochimica et Cosmochimica Acta, v. 56, p. 3583-3587.
REFERENCE_XXO Putkonen, J., 2001, Quantifying the moraine degradation by exposure age dating of surface boulders: Geological Society of America Abstracts with Programs, v. 33, no. 6, p. A285-A286.
REFERENCE_XXO Weber, F. R., 1986, Glacial geology of the Yukon-Tanana Upland, in Hamilton, T. D., Reed, K. M., and Thorson, R. M., eds., Glaciation in Alaska -- The Geologic Record: Anchorage, Alaska Geological Society, p. 79-98.
REFERENCE_XXO Weber, F. R., and Hamilton, T. D., 1984, Glacial geology of the Mt. Prindle area, Yukon-Tanana Upland, Alaska, Short Notes on Alaskan Geology 1982, Alaska Division of Geological and Geophysical Surveys Professional Report 86, p. 42-48.
REFERENCE_XXO  Westgate, J. A., Preece, S. J., Froese, D. G., Walter, R. C., Sandhu, A. S., and Schweger, C. E., 2001, Dating Early and Middle (Reid) Pleistocene Glaciations in Central Yukon by Tephrochronology: Quaternary Research, v. 56, p. 335-356.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/92-1.jpg

CAPTION_XXO Fig 1.  Fig. 1.  Map of the central Yukon Tanana Upland, showing paleoglacier extents as mapped and entered into the Geographic Information System (GIS).

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/92-2.gif

CAPTION_XXO Fig 2.  

INSERT_PAGE_BREAK_HERE
TITLE_XXO HOLOCENE HISTORY OF THE GREAT KOBUK SAND DUNES, NORTHWESTERN ALASKA

AUTHORS_XXO MANN, DANIEL H. (1); Heiser, Patricia A. (2); Finney, Bruce P. (3)

AUTHOR_1_XXO (1) University of Alaska; dmann@mosquitonet.com
AUTHOR_2_XXO (2) Cold Regions Research  Laboratory, Anchorage
AUTHOR_3_XXO (3) University of Alaska

PARAGRAPH_1_XXO Located just north of the Arctic Circle, the Great Kobuk Sand Dunes (GKSD) are an inland dune field that is closely surrounded by boreal forest.  The history of the GKSD tells us about changes in aridity, a climatic parameter whose history is poorly understood at high latitudes.  Vegetated dunes in several states of geomorphic preservation surround the active dune field today, evidencing a complex history of Holocene activity.  Small lakes in the forest bordering the dunes accumulate wind-blown sand.  We use 14C-dated, lake-sediment cores to reconstruct a continuous history of sand influx over the last 8000 years.  The validity of this record is supported by limiting ages obtained from stratigraphic sections within the dune field.  The extent of the GKSD underwent a fluctuating shrinkage coincident with Neoglaciation.  This downsizing trend was interrupted by periods of increased sand deposition into lakes occurring 4800-4200, 3300-2600, 1300-700, and 300-100 calendar years ago.  Aridity in the Kobuk valley during the Holocene probably was controlled by the frequency of North Pacific storms entering the region in late summer.  Our results describe the first continuous history of changing moisture balance for central Beringia during the Holocene and comprise a baseline against which future records of climatic and ecological change in this region can be compared.

INSERT_PAGE_BREAK_HERE
TITLE_XXO HIGH-RESOLUTION TEMPERATE GLACIER DEFORMATION -- IMPLICATIONS ABOUT THE FORM OF THE FLOW LAW OF ICE

AUTHORS_XXO MARSHALL, HANS-PETER (1); Pfeffer, Tad (2); Harper, Joel (3); Humphrey, Neil (4)

AUTHOR_1_XXO (1) INSTAAR and Dept of Civil, Environmental, and Architectural Eng; Univ of Colorado at Boulder; marshalh@colorado.edu
AUTHOR_2_XXO (2) INSTAAR and Dept of Civil, Environmental, and Architectural Eng; Univ of Colorado at Boulder; pfeffer@tintin.colorado.edu
AUTHOR_3_XXO (3) Dept of Geology and Geophysics; Univ of Wyoming; JoelH@uwyo.edu
AUTHOR_4_XXO (4) Dept of Geology and Geophysics; Univ of Wyoming; neil@uwyo.edu

PARAGRAPH_1_XXO 	The rheological behavior of ice plays a pivotal role in predicting the response of glaciers and ice sheets to climate change, understanding the evolution of glacial landscapes, and assigning time-depth scales to ice cores for measurement of long-term climate history.  While interest in glacier and ice sheet mechanics has grown substantially during the last 50 years, the material properties of glacial ice are still not well established.  Ice appears to deform solely in response to deviatoric stress with a stress dependent viscosity.  The commonly applied flow law for glacial ice gives the strain rate as a function of the deviatoric stress raised to a power “n”.
PARAGRAPH_XXO         The value of this parameter “n” has been a long debated and unresolved issue; 3 is commonly used, but values from 1 to more than 4 have been reported.  Because natural glacier ice deforms in secondary (or steady-state) creep, very long test durations are required to accurately represent this behavior in the laboratory.  To prevent errors in measurements arising from year-long laboratory tests, most experiments have been performed at stresses much higher than those found in glaciers and ice sheets.  These high-stress experiments have yielded values of “n” of 3-4, which agree reasonably well with results from in-situ measurements on the large ice sheets and have become the values most often used by modelers.  Deviations from this flow law are usually attributed to fabric and other heterogeneous ice properties, or inaccurate assumptions about the applied stress (at low stresses).    
PARAGRAPH_XXO 	Using the highest-resolution data set to-date of deformation in temperate glacier ice (1), we examined the three-dimensional strain-rate tensor and its relationship to the inferred stress acting on this 198m X 165m X 240m block of natural glacial ice on Worthington Glacier, AK.  Deformation of the block was evaluated by more than 21,000 measurements of the tilting of 31 boreholes extending to near the glacier’s bed, located at a depth of 180-200 m.  The borehole tilt observations yielded the two horizontal components of the velocity vector.  These velocity data were then interpolated to a three-dimensional grid (24 X 11 X 99 nodes) with vertical coordinates referenced to the irregular surface of the glacier (Fig. 1).  
PARAGRAPH_XXO 	Our results show that below a depth of 115 m, the ice follows a non-linear flow law with a power exponent of approximately 3, as expected from past work.  Above 115m, however, our analysis indicates linear viscous flow (Fig. 2).  A sharp transition between the two flow regimes is likely caused by a change in the dominant mechanism from grain boundary sliding (diffusional flow) near the surface to dislocation and intra-granular deformation at depth.  This type of behavior at low stress has very recently been reported from laboratory experiments using new methods (2), and has long been observed in high-temperature metals (which deform in a manner similar to ice) (3).
PARAGRAPH_XXO The deformation observed in the upper half of this 200 m thick glacier implies that much of the ice in the world’s small mountain glaciers may best be defined by a linear viscous flow law.  This finding bears on forecasts of short-term global response to climate change, for the world’s small glaciers are the fastest-acting component of global glacier mass balance; on century time-scales they area dominant contribution to sea level change (4). 

REFERENCE_XXO 1.  J.T. Harper et. al.,. Journal of Geophysical Research 106, 8547 (2001).
REFERENCE_XXO 2.  D.L. Goldsby, D. L. Kohlstedt, Journal of Geophysical Research 106, 11017 (2001).
REFERENCE_XXO 3.  I. Servi, N. Grant, Journal of Metals 3, 909 (1951).
REFERENCE_XXO 4.  M. F. Meier, Science 226, 1418 (1984).

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/37-1.jpg

CAPTION_XXO Fig 1.  3-D grid of velocity / strain-rate data on<br><br>Worthington Glacier, Alaska.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/37-2.jpg

CAPTION_XXO Fig 2.  Log-log plot of effective strain rate and <br><br>effective deviatoric stress.  The slope of a linear fit to this data defines the flow law exponent "n".

INSERT_PAGE_BREAK_HERE
TITLE_XXO ICELANDIC FISHING PEOPLE'S ADAPTIVE RESPONSES TO CLIMATIC VARIABILITY:  IMPLICATIONS FOR FISHERIES POLICIES

AUTHORS_XXO MCGOODWIN, JAMES R.

AUTHOR_1_XXO University of Colorado; mcgoodwi@spot.colorado.edu

PARAGRAPH_1_XXO 
PARAGRAPH_XXO Abstract:   This paper discusses preliminary findings and future plans regarding a research project which is aimed at exploring the dynamic linkages between Iceland's fishing people and climatic and marine-ecological variability, and change.  Tentative suggestions will also be offered regarding the development of sustainable fisheries-management policies for Iceland's fishing people, who in the near future may have to cope with rapid climatic and environmental change.

INSERT_PAGE_BREAK_HERE
TITLE_XXO HOLOCENE MULTI-PROXY ANALYSES FROM PEATLANDS, BLUEFISH BASIN, YUKON TERRITORY.

AUTHORS_XXO MERCIER, GENEVI¯VE (1); Lacelle, Denis (2); Lauriol, Bernard (3); Duguay, Claude (4)

AUTHOR_1_XXO (1) Department of Geography, University of Ottawa, Ottawa, ON, Canada.; gmercier78@hotmail.com
AUTHOR_2_XXO (2) Department of Geography, University of Ottawa, Ottawa, ON, Canada.; lacelledenis@hotmail.com
AUTHOR_3_XXO (3) Department of Geography, University of Ottawa, Ottawa, ON, Canada.; blauriol@uottawa.ca
AUTHOR_4_XXO (4) Centre dàÅtudes nordiques et dÅpartement de gÅographie, UniversitÅ Laval Sainte-Foy, QuÅbec, Canada.

PARAGRAPH_1_XXO Multi-proxy analyses were carried out on cores taken from peatland surfaces developed in thermokarst depressions to determine the vegetation succession and climatic conditions prevailing during the Holocene.  12 cores were taken from the Bluefish Basin (Yukon Territory) which is located in the continuous permafrost zone.  Both macrofossils and stable isotopes analyses (d18O and dD) were carried out on the cores.  A 1.5 m core was recovered from the center of a plateau, which overlies a late Wisconsin lakebed (gyttja).  The results indicate a succession from 9,950 BP from an open water surface (Zone 1) to a nutrient-rich eutrophic shallow pond (Zone 2).  A decrease in aquatics and shallow water species is observed around 8,200 BP (Zone 3).  Zone 4 consists of herbaceous fragments and charred particles. Eleven conventional radiocarbon dates were obtained at the contact between the lakebed sediment and organic matter.  The dates indicate a transition from open water surfaces to an important period of mosses, Sphagnum sp. and herbaceous sp. accumulation between 3,500 BP and 1,500 BP.  The 18O and D data of the peat pore water provides some information about the hydrological history of the sites.  The d18O and dD indicate that the majority of the ground ice (water) is derived from meteoric rainfall and snow meltwater.  In the case of ground ice extracted from the lakebed sediment (gyttja), evaporation influences the isotopic composition of the water, enriching the water in 18O and D.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/32-1.jpg

CAPTION_XXO Fig 1.  Macrofossils concentrations per 150 cc of sediment from Bluefish-1. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO LATE PLEISTOCENE MAMMALS OF NEW SIBERIA ISLAND (RUSSIAN ARCTIC)

AUTHORS_XXO NIKOLSKIY, PAVEL A.

AUTHOR_1_XXO Geological Institute RAS, Moscow, Russia; nikol@geo.tv-sign.ru

PARAGRAPH_1_XXO In summer of 2000 and 2001 in the framework of the Russian-American archeological Project "Zhokhov-2000" a representative collection of the late Pleistocene mammal remains (more than 1300 bones) was collected on New Siberia Island (East-Siberian Sea, 75N). This is the northernmost Pleistocene fauna known in Beringia. The taphonomy of the material indicates natural or close to natural composition of the fauna. The following species were identified:
PARAGRAPH_XXO Equus caballus (horse);
PARAGRAPH_XXO Bison priscus (steppe bison);
PARAGRAPH_XXO Mammuthus primigenius (wooly mammoth);
PARAGRAPH_XXO Rangifer tarandus (caribou);
PARAGRAPH_XXO Ovibos moschatus (muskox);
PARAGRAPH_XXO Coelodonta antiquitatis (wooly rhinoceros);
PARAGRAPH_XXO Lepus tanaiticus (late Pleistocene hare);
PARAGRAPH_XXO Saiga tatarica (saiga);
PARAGRAPH_XXO Canis lupus (wolf);
PARAGRAPH_XXO Alopex lagopus (arctic fox);
PARAGRAPH_XXO Lemmus obensis (Siberian lemming);
PARAGRAPH_XXO Dicrostonix sp. (collared lemming),
PARAGRAPH_XXO Gulo gulo (wolverine);
PARAGRAPH_XXO Ursus sp. (bear, probably polar bear).
PARAGRAPH_XXO Remains of bison and horse markedly dominate in the collection. The bones of wooly mammoth, caribou, and arctic hare are numerous. Muskox is common. Findings of the other species are rare.
PARAGRAPH_XXO This new northernmost fauna was compared with the material from the Oyogos Yar (north of Yana-Indigirka lowland) we collected in 1996-2000, and more southern faunas of central and southern Yakutia. The comparison shows that during late Pleistocene the extremely northern fauna of New Siberia Island was very much similar to other faunas of western Beringia in abundance, composition, and diversity.
PARAGRAPH_XXO Of special interest is à new set of radiocarbon dates (more than 60) obtained in Geological Institute (Moscow) by Dr. L.D. Sulerzhitsky. Most dates are based on mammoth bones. An analysis shows:
PARAGRAPH_XXO 1. Mammoth fauna was permanently presented in NS Island (which was a part of land together with now flooded shelf) throughout the late Pleistocene covered by radiocarbon range. Whether this inhabitance had a permanent or seasonal character is so far unclear. Some species did not migrate.
PARAGRAPH_XXO 2. The dates show clear modality away from full glacial period (22000 - 17000 BP). The peak of the numbers falls on the interval 45000-24000 BP and (to the least extent) on the interval 17000-10000 BP. Dated bones are less represented during the interval 22000-17000 BP. Thus, there is an obvious dependence of the numbers of animals inhabiting the area and the global temperature.
PARAGRAPH_XXO This regularity decreases from north to south. Whereas in the data from central Yakutiya (Sulerzhitsky and Romanenko, 1997), the decrease of dates during full glacial period is not strongly expressed, in the data from New Siberia Island this feature is more pronounced. The same is for eastern Beringia. Dates for Alaska do not show clear modality away from full glacial period (Guthrie, 1990).
PARAGRAPH_XXO Abundance of food resources was favorable for ancient man populating these latitudes in the late Pleistocene.

REFERENCE_XXO Guthrie, R. D., 1990, Frozen fauna of the mammoth steppe: the story of Blue Babe: The University of Chicago Press. Chicago and London, p. 242-244.
REFERENCE_XXO Sulerzhitsky, L. D., Romanenko F. A., 1997, Age and distribution of the �Mammoth faunaæ of the polar region of Asia (radiocarbon dating results): Cryosphere of Earth, v. 1, No 4, p. 12-19.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/43-1.gif

CAPTION_XXO Fig 1.  The most important localities that have produced remains of Upper Pleistocene mammals in northern West Beringia.<br><br><br><br>Key to numbered localities. 1. Bykovsky peninsular; 2. Mus-Khaja; 3. Lower Adycha; 5 New Siberia Isl.; 6. Bolshoy Liakhovsky Isl.; 7. Ojogos Yar; 8. Khaptashinsky Yar; 9. Bereliokh; 10. Right trib. of Indigirka (numerous local.); 11. Kuropatochia; 12. Alazeja; 13. Chukochia; 14. Duvany Yar; 15 Wrangel Isl.<br><br>

INSERT_PAGE_BREAK_HERE
TITLE_XXO 3D SEISMIC EXPLORATON DATA OFFSHORE WESTERN NORWAY - EVIDENCE OF PLEISTOCENE ICE STREAMS, SUBGLACIAL DRAINAGE AND DEGLACIATION PATTERNS

AUTHORS_XXO NYGAARD, ATLE (1); Sejrup, Hans Petter (2); Haflidason, Haflidi  (3); Cecchi, Marcello (4)

AUTHOR_1_XXO (1) Department of Geology, University of Bergen; atle.nygard@geol.uib.no
AUTHOR_2_XXO (2) Department of Geology, University of Bergen; Hans.Sejrup@geol.uib.no
AUTHOR_3_XXO (3) Department of Geology, University of Bergen; Haflidi.Haflidason@geol.uib.no
AUTHOR_4_XXO (4) Enterprise Oil Norway

PARAGRAPH_1_XXO Offshore western Norway, in the Northern North Sea / the southernmost Møre shelf, the Måløy Plateau is a large bank area flanking the outlet of the Norwegian Channel. A 3D survey covering 950 km2 (app. 1/4 of the Plateau) has been investigated. The strength of the 3D seismic method is its horizontal (spatial) resolution, while its weakness is the vertical (temporal) resolution, limited by the low frequency range designed to image deeper reservoirs.
PARAGRAPH_XXO The Måløy Plateau consists of a sequence of glacial, interglacial and deltaic sediments up to 500 m thick above the glacial unconformity. The stratigraphy of the Måløy Plateau is correlated with the stratigraphy of the Norwegian Channel/North Sea Fan provided by the Troll core and new geological borings on the outer Møre shelf/upper slope. In the early and Middle Pleistocene, the area was strongly influenced by northward moving ice streams, indicated by >30 km long and straight glacial lineations on top of several acoustically massive units, interpreted as tills. Superimposed on these units an up to 150 m thick deltaic sequence has been deposited, prograding from the mainland. Channels indicating subaerial exposure incise the sub-horizontal upper surface of the delta, about 250 m below the present day sea level. From its stratigraphic position a late Middle Pleistocene/Late Pleistocene age is suggested. Stratigraphically above the delta sequence, seismically massive, sheet-like deposits interpreted as subglacially deposited tills do not show the strong lineation characteristic of the lower stratigraphic levels. However, anastomosing and dendrittic channels patterns interpreted as subglacial drainage patterns are identified in the sheet-like deposits. They occur independent of local dip directions more than 300 m below the present day sea level, and suggest upslope flow directions. The uppermost sheet-like till sequence deposited by the ice which reached the shelf edge during the last glacial maximum shows weak NNW lineation. This unit forms the base of an up to 50 thick composite sequence of ridges deposited towards SW, indicated by a strong directional imprint on the seabed. The thick sequence is deposited after the collapse of the ice in the Norwegian Channel (15 ka), and a partial deglaciation of the Måløy Plateau. The lack of supporting ice in the Norwegian Channel probably created a significant imbalance in the surface profile of the ice on the Møre shelf, creating a SW directed advance before the final deglaciation of the Plateau at 12.7 ka.  

INSERT_PAGE_BREAK_HERE
TITLE_XXO DIFFERENTIAL GPS INFRASTRUCTURE SUPPORT FOR REAL-TIME AND POST-PROCESSED SURVEYS IN BARROW, ALASKA

AUTHORS_XXO O'NEEL, SHAD (1); Johns, Bjorn (2)

AUTHOR_1_XXO (1) University NAVSTAR Consortium; shad@unavco.ucar.edu
AUTHOR_2_XXO (2) University NAVSTAR Consortium; bjorn@unavco.ucar.edu

PARAGRAPH_1_XXO The University NAVSTAR Consortium (UNAVCO) is providing high-precision differential Global Positioning System (GPS) support to the Barrow Area Science Consortium (BASC) in Barrow, Alaska beginning May 2002. System installation, technical support, and training will be provided by UNAVCO, and the system will be available year-round to scientists hosted by BASC. By having a dedicated GPS system at BASC, visiting scientists will be able to collect quality GPS data without having to obtain their own GPS equipment. By adding real-time kinematic (RTK) functionality to the base and rover GPS receivers, the system will provide centimeter level precision in real-time in a 5-10 kilometer radius from the base station at BASC. Real-time stakeouts allow the user to return to an exact location without any markers left in the ground. This will require a base station transmitter at BASC and a repeater to cover the Barrow Environmental Observatory (BEO).
PARAGRAPH_XXO GPS users worldwide are increasingly able to rely upon access to local base station data collected continuously at a predetermined precise location. These base stations are the starting point when processing local GPS data, and allow the collected data to be referenced to precise real-world coordinates. A Trimble 5700 dual-frequency geodetic GPS base station will be located at BASC.  Local users can operate this station as needed, and they will have full control over data collection settings such as sample rate. 
PARAGRAPH_XXO UNAVCO is simultaneously collaborating with the University of Alaska, Fairbanks to install a SuomiNet (atmospheric and geodetic GPS network) permanent GPS station at the NOAA Climate Monitoring and Diagnostics Laboratory (CMDL) facility in Barrow. This permanent station may be installed as soon as May 2002, and will also provide local GPS base station data. Data from SuomiNet sites are archived at UNAVCO, and they are publicly available via the Internet. This site will be a good backup to the planned base station at BASC, as it will provide another source of geodetic GPS control.
PARAGRAPH_XXO Successful GPS results require properly trained GPS users, and technical support is critical to ensure effective use of the equipment provided. This support will be provided jointly by UNAVCO and BASC, where UNAVCO provides 1-2 training sessions per season at Barrow, and also provides on-demand training in Boulder to researchers on their way to Barrow. BASC will provide a local GPS contact for the GPS users. With time, local users will become more familiar with the equipment, and they are likely to provide some support to their colleagues who want to use the equipment for the first time. A dedicated section on the UNAVCO web page (www.unavco.ucar.edu) will also provide specific documentation for the GPS system at BASC.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/9-1.jpg

CAPTION_XXO Fig 1.  GPS survey of Point Barrow coastline erosion.

INSERT_PAGE_BREAK_HERE
TITLE_XXO DIFFERENTIAL GPS INFRASTRUCTURE SUPPORT FOR REAL-TIME AND POST-PROCESSED SURVEYS AT THE BARROW AREA SCIENCE CONSORTIUM FACILITIES, BARROW, ALASKA

AUTHORS_XXO O'NEEL, SHAD (1); Johns, Bjorn (2)

AUTHOR_1_XXO (1) UNAVCO; shad@unavco.ucar.edu
AUTHOR_2_XXO (2) UNAVCO; Bjorn@unavco.ucar.edu

PARAGRAPH_1_XXO The University NAVSTAR Consortium (UNAVCO) is providing high-precision differential Global Positioning System (GPS) support to the Barrow Area Science Consortium (BASC) in Barrow, Alaska beginning May 2002. System installation, technical support, and training will be provided by UNAVCO, and the system will be available year-round to scientists hosted by BASC. By having a dedicated GPS system at BASC, visiting scientists will be able to collect quality GPS data without having to obtain their own GPS equipment. By adding real-time kinematic (RTK) functionality to the base and rover GPS receivers, the system will provide centimeter level precision in real-time in a 5-10 kilometer radius from the base station at BASC. Real-time stakeouts allow the user to return to an exact location without any markers left in the ground. This will require a base station transmitter at BASC and a repeater on the KBRW tower to cover the Barrow Environmental Observatory (BEO).
PARAGRAPH_XXO GPS users worldwide are increasingly able to rely upon access to local base station data collected continuously at a predetermined precise location. These base stations are the starting point when processing local GPS data, and allow the collected data to be referenced to precise real-world coordinates. A Trimble 5700 dual-frequency geodetic GPS base station will be located at BASC.  Local users can operate this station as needed, and they will have full control over data collection settings such as sample rate. 
PARAGRAPH_XXO UNAVCO is also currently collaborating with the University of Alaska, Fairbanks to install a SuomiNet (atmospheric and geodetic GPS network) permanent GPS station at the NOAA Climate Monitoring and Diagnostics Laboratory (CMDL) facility in Barrow. This permanent station may be installed as soon as May 2002, and will also provide local GPS base station data. Data from SuomiNet sites are archived at UNAVCO, and they are publicly available via the Internet. This site will be a good backup to the planned base station at BASC, as it will provide another source of geodetic GPS control.
PARAGRAPH_XXO Successful GPS results require properly trained GPS users, and technical support is critical to ensure effective use of the equipment provided. This support will be provided jointly by UNAVCO and BASC, where UNAVCO provides 1-2 training sessions per season at Barrow, and also provides on-demand training in Boulder to researchers on their way to Barrow. BASC will provide a local GPS contact for the GPS users. With time, local users will become more familiar with the equipment, and they are likely to provide some support to their colleagues who want to use the equipment for the first time. A dedicated section on the UNAVCO web page (www.unavco.ucar.edu) will also provide specific documentation for the GPS system at BASC.

INSERT_PAGE_BREAK_HERE
TITLE_XXO THE HUMAN ROLE IN EARLY HOLOCENE ARCTIC FOOD WEBS: SOME THOUGHTS FROM NORTHERN SIBERIA

AUTHORS_XXO ODESS, DANIEL (1); Pitulko, Vladimir V. (2); Anisimov, Mikhail A. (3); Basilyan, Alexander E. (4); Giria, Evgeny Yu. (5); Nikolsky, Pavel A. (6); Pavlova, Elena Yu. (7); Tumskoy, Vladimier E. (8)

AUTHOR_1_XXO (1) University of Alaska Museum; ffdpo@uaf.edu
AUTHOR_2_XXO (2) Institute for the History of Material Culture, RAS; archeo@archeo.ru
AUTHOR_3_XXO (3) Arctic and Antarctic Research Institute, RAS
AUTHOR_4_XXO (4) Institute for Geology, RAS
AUTHOR_5_XXO (5) Institute for the History of Material Culture, RAS
AUTHOR_6_XXO (6) Institute for Geology, RAS
AUTHOR_7_XXO (7) Arctic and Antarctic Research Institute, RAS
AUTHOR_8_XXO (8) Moscow State University

PARAGRAPH_1_XXO Much of the archaeological research conducted in the Arctic over the past 30+ years has focussed on how humans have adapted to the natural environment, and, more recently, how they have responded to environmental change.  Their role as high-order carnivores in Arctic food webs has gone largely unexplored and unappreciated.  Elsewhere in the archaeological world, explicitly ecological research programs have increasingly emphasized the role of humans as active and even intentional agents of environmental change.  Where before it had been assumed that the human role in environmental change was negligible prior to the rise of agriculture, agro-pastoralism, or even the industrial revolution, we now recognize that humans fundamentally altered local and even regional ecosystems long before these developments in many parts of the world.  
PARAGRAPH_XXO On Pacific Islands, human arrival is marked by the extinction of some species and the introduction of others. Demographic profiles in catastrophically killed bison populations from Early and Middle-Holocene sites in the lower 48 states suggest specific age sets had been selectively removed by human predators.  Fire histories in some areas suggest humans practiced intentional burning to increase the yield of economically important plant foods and / or to increase the populations of economically important animals.  The debate over whether humans caused the extinction of Pleistocene megafauna in the New World continues to simmer.  Stellar’s Sea Cow now only floats in specimen jars at museums, but its bones are common in prehistoric archaeological sites from the Aleutian Islands.
PARAGRAPH_XXO The assumption that there was an “Ecological Indian” (Krech 1999) living in harmony with but not having any impact on the environment is itself falling prey to a variety of contrary archaeological and paleoecological data.  In the Arctic, where human population densities have remained low until quite recently, and where people have articulated with food webs primarily as foragers, we have taken for granted that humans were subject to the vagaries of the environment and environmental change, but I suggest we have also assumed that relatively small numbers of people hunting with what to our modern eyes appear to be primitive tools did not and could not have a significant impact on the animal populations on which they preyed.  Extinction is but the most dramatic of many possible impacts human predators may have on community ecology.
PARAGRAPH_XXO Humans have lived in the North American Arctic at least since the end of the Pleistocene, but occupation sites that preserve faunal remains, the most direct evidence for how they interacted with food webs, are very scarce until the Middle Holocene.  Humans have occupied the Russian Arctic for a much longer time, and sites with well-preserved faunal remains go back to the previous interglacial (Pitulko et al., 2002 and this conference).  Ongoing investigations under the auspices of the research program “Zhokhov 2000” are building on previous efforts (e.g., Pitulko and Kasparov 1996) and exploring the role of human predators in Arctic ecosystems.  While work is still underway, preliminary results confirm that people living on what is now Zhokhov Island in the Early Holocene were taking large numbers of polar bears relative to other species whose bones are found in the site.  It is not yet clear whether humans targeted a specific segment of the polar bear population through selective hunting practices, but smaller, perhaps female, individuals appear most common.  The removal of large numbers of polar bears from the food web, particularly if a specific segment of the population was targeted, would have a significant impact on community ecology.  
PARAGRAPH_XXO We suggest that in nearly all cases, even those going back to the last interglacial, where the archaeological datasets provide fine enough resolution to address the issue, humans have had a potentially significant impact on arctic food webs and, by extension, on community paleoecology.  It follows from this conclusion that future efforts to reconstruct arctic food webs and past communities of plants and animals should explicitly consider the role of human predators in the ecosystem.
PARAGRAPH_XXO Krech, Shepard  III  1999.  The Ecological Indian.  New York: Norton
PARAGRAPH_XXO Pitulko, V.V., and A.K.Kasparov. 1996. Ancient Arctic Hunters: Material Culture and Survival Strategy. Arctic Anthropology 1996, 33(1):1-36.
PARAGRAPH_XXO Pitulko, V.V., M.A.Anisimov, A.E.Basilyan, E.Yu.Giria, P.A.Nikolsky, D.P.Odess, E.Yu. Pavlova, and V.E.Tumskoy 2002. Making a New Step: Zhokhov 2000 project, Expedition of 2001. Abstracts of the ARCSS Workshop held in Seattle, February 2002. 

REFERENCE_XXO Krech, Shepard  III  1999.  The Ecological Indian.  New York: Norton
REFERENCE_XXO Pitulko, V.V., and A.K.Kasparov. 1996. Ancient Arctic Hunters: Material Culture and Survival Strategy. Arctic Anthropology 1996, 33(1):1-36.
REFERENCE_XXO Pitulko, V.V., M.A.Anisimov, A.E.Basilyan, E.Yu.Giria, P.A.Nikolsky, D.P.Odess, E.Yu. Pavlova, and V.E.Tumskoy 2002. Making a New Step: Zhokhov 2000 project, Expedition of 2001. Abstracts of the ARCSS Workshop held in Seattle, February 2002. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO GEOLOGY, GEOMORPHOLOGY, AND LATE PLEISTOCENE/HOLOCENE HISTORY OF RELIEF IN THE LENA DELTA, EAST SIBERIA.

AUTHORS_XXO PAVLOVA, ELENA YU. (1); Dorozhkina, Marina V. (2)

AUTHOR_1_XXO (1) State Research Center of Russian Federation Arctic and Antarctic Research Institute; bunge@mail.ru
AUTHOR_2_XXO (2) State Research Center of Russian Federation Arctic and Antarctic Research Institute; mdorozhkina@mail.ru  

PARAGRAPH_1_XXO Several geomorphologic levels differing in height and age with a different spatial distribution are identified in the Lena delta: low floodplain with a complex  of modern channel features of the present age; high floodplain of the Late Holocene age; first above the floodplain accumulative terrace of the Early-Middle Holocene age; second above the floodplain erosion terrace  of the Late Pleistocene-Early Holocene age; third above the floodplain erosion terrace  of the Late Pleistocene age; denudation relics worked out on the Paleozoic rock and pre-Pleistocene  pebble-conglomerate rocks. An analysis of published data and the results of studies for the last 4 years allow us at present to outline the main development stages of the territory.
PARAGRAPH_XXO Late Pleistocene. The  development of the territory  occupied now by the Lena delta, was closely connected in the Late Pleistocene with the regressive-transgressive sea cycles (Romanovsky et al., 1997) that determined primarily the erosion basis and as a result the change of intensity of the accumulation-erosion processes on land.
PARAGRAPH_XXO During the period of a long sea regression during the Pleistocene, extensive shallow Laptev Sea shelf areas dried up to a depth of 100-140 m (Selivanov, 1996). Under the conditions of prevailing continental sedimentation the formation of Late Pleistocene syncryogenetic  ice complex deposits occurred (Sher, 1997). At Sartan time, the coastline was located in 250-300 km north of the modern Lena delta coastline (Atlas). The main Lena runoff was in the northern and northwestern direction along the valleys coinciding with the modern Olenyokskaya and Bolshaya Tumatskaya branches. The fragments of these paleo-valleys are fixed at present on the Laptev Sea shelf. At this time the third above the floodplain erosion terrace formed within the modern delta territory due to intense entrenchment of the water flows. The plains of alluvial and lake genesis formed simultaneously in the western sector of the modern Lena delta (Gusev, 1961; Atlas).
PARAGRAPH_XXO End of the Late Pleistocene – Early Holocene. The relief formation at the end of the Late Pleistocene- Early Holocene occurred under the complicated paleogeographical conditions of the post-glacial sea transgression development and more active recent tectonic movements.
PARAGRAPH_XXO The first stage of the post-glacial transgression that began 18 kyr BP belongs to this period (Romanovsky et al., 1997). As noted by these authors, the most important features of the first transgression stage was a high rate of sea level rise, especially beginning from 13 kyr BP. Transgression, especially at the beginning was of an ingression character with mouth area of river paleo-valleys transforming to marine freshened bays. The average rate of the coastline displacement towards land comprised 40-60 m/year. By 11 kyr, the sea level raised to a 40 m isobath (Are, 1982).
PARAGRAPH_XXO At the end of the Late Pleistocene – Early Holocene, recent tectonic movements within the modern Lena delta become more active (Grigoriev, 1993; Pavlova and Dorozhkina, 2000, 2000a). The predominant stable arched block uplift of the western delta sector and a subsidence of the eastern sector caused a non-unidirectional development of the western and eastern delta sectors from the end of the Late Pleistocene. A divide zone of two delta areas that are characterized by a non-unidirectional tectonic regime has a submeridonal strike and passes between the Malaya and Bolshaya Tumatskaya branches. The difference in the tectonic regime of the western and eastern delta sectors resulted later in the formation of the entire terrace complex in the western delta sector whereas only two floodplain levels and relics of the third above the floodplain terrace were formed in the eastern sector. The formation of the second above the floodplain erosion terrace belongs to the end of the Late Pleistocene – Early Holocene.
PARAGRAPH_XXO Early Holocene – first half of the Middle Holocene. The formation of alluvial deposits of the first above the floodplain terrace in the Lena delta began as a minimum 8.5 kyr BP, i.e. in the Early Holocene rather than 4.5 kyr according to Korotayev (Korotayev, 1984, 1991). The formation of the first above the floodplain terrace occurred at the background of the second post-glacial transgression stage (Romanovsky et al., 1997) that began 8-7 kyr BP and was characterized by a slow level rise of the global ocean and climate warming. Stabilizing of the sea basin level belongs approximately to 6 kyr BP, which is in agreement with the Laptev Sea study data (Bauch et al., 1999).
PARAGRAPH_XXO The sea transgression and climate warming were the decisive factors of active thermal abrasion of sea shores. Lake thermokarst was widespread (Romanovsky et al., 1997). The formation of alasy basins confined to the surface of the third above the floodplain terrace continued.
PARAGRAPH_XXO The main Lena River runoff  in the Early-Middle Holocene was along the Olenyokskaya branch in the northwestern direction and along the Malaya and Bolshaya Tumatskaya branches in the northern direction. 
PARAGRAPH_XXO End of the Middle Holocene – Late Holocene. The formation of the high floodplain occurred during the end of the Middle Holocene – Late Holocene at a relative sea level close to a modern one (Are, 1982) or greater by not more than 1-3 m (Kaplin and Selivanov, 1999). The absence of a significant sea influence on the formation of delta deposits in the Late  Holocene is confirmed by data of modern studies (Schwamborn, et. al., 2000a).
PARAGRAPH_XXO At this time the direction of the main runoff within the Lena delta changes to the north-east-eastward due to more active recent tectonic movements that began at the end of the Late Pleistocene-Early Holocene resulting in the arched block uplift of the western delta sector and a prevailing subsidence of the eastern sector. The main runoff was along the Trofimovsksya and Bykovskaya branches with decreasing runoff in the Olenyokskaya and Malaya and Bolshaya Tumatskaya branches. As a result of transformed main runoff, the most active accumulation of alluvial deposits begins from this time in the central area and in the northeastern delta sector. During the second half of the Holocene, the river and ravine thermoerosion and thermokarst processes actively developed contributing to the general dissection of the delta relief. The formation of alasy continued and bulgunyakhi formed confined to the first above the floodplain terrace and the bottoms of alasy basins of the third above the floodplain terrace.
PARAGRAPH_XXO Modern stage.  At the modern stage, the formation of low and high floodplains widespread by area within the Lena delta occurs.  Their formation is closely connected with the hydrological regime of the delta being primarily due to the changed Lena water content, distribution of the water runoff and sediment load and intense spreading of the flood flow below the main delta branching node by arms. The development of extensive areas throughout the entire northeastern delta sector annually flooded during the flood period is determined by the maximum water runoff and discharges of suspended sediment in the Trofimovskaya branch. The minimum of the water runoff and suspended sediment discharges in the Olenyokskaya and Tumatskaya branches (western delta sectors) governs a restricted by-area development of the low floodplain along the branches. The same tendency is preserved for the high floodplain.
PARAGRAPH_XXO The marine factors control the relief formation within the external margin of the Lena River delta. Among the group of marine factors, the most significant are surge sea level oscillations. Tidal phenomena play a noticeable relief-forming role only within the open external northern and northeastern margin of the Lena mouth area on the protrusion delta formation segments.
PARAGRAPH_XXO At the current stage the fluvial processes that govern the creation of accumulation relief features of the floodplain levels along the branches and erosion (thermoerosion) destruction of shores play the main role in the formation of the Lena delta relief. The processes of thermoerosion due to the impact of temporary water flows are most active within the third above the floodplain terrace and account for the development of a complicated branched system of deeply entrenched ravines in the ice complex deposits with a high ice content. The processes of thermoerosion are spread to a lesser extent at the surface of the second above the floodplain terrace. Here, a leading role in the relief formation belongs to thermokarst, which generates numerous thermokarst lakes. The thermokarst processes are less typical of the floodplain levels and the first above the floodplain terrace where shallow thermokarst lakes form. The processes of frost heaving result in the formation of the heaving hills - bulgunyakhi at the surface  of the high floodplain and the third above the floodplain terrace. The processes forming a crack-polygonal micro-relief actively occur at practically all terrace levels except for the lowest  near-channel and coastal-marine segments. The processes of eolian accumulation and deflation are most pronounced at the surface of sand relics of the second above the floodplain terrace and on the segments of near-channel shoals and islets not fixed by vegetation.
PARAGRAPH_XXO We note that the Lena delta is located within a seismically active zone to which the epicenters of earthquakes with a magnitude of up to M=3.5-6 (Imayev et al., 1996) are confined. The confining of the Lena delta to a seismically active zone is evidence of the continuing recent tectonic movements at the modern stage of the territory development.

INSERT_PAGE_BREAK_HERE
TITLE_XXO COLUMBIA GLACIER 2002: PRESENT STATUS AND FORECAST LIFETIME

AUTHORS_XXO PFEFFER, W TAD (1); Meier, Mark F. (2); Krimmel, Robert M. (3); Cohn, Josh (4)

AUTHOR_1_XXO (1) INSTAAR - University of Colorado; pfeffer@tintin.colorado.edu
AUTHOR_2_XXO (2) INSTAAR - University of Colorado; meiermf@spot.colorado.edu
AUTHOR_3_XXO (3) USGS Tacoma; rkrimmel@usgs.gov
AUTHOR_4_XXO (4) INSTAAR - University of Colorado; josh_cohn@hotmail.com

PARAGRAPH_1_XXO Columbia Glacier is a ca. 1000 km^2 temperate tidewater glacier terminating in Alaska's Prince William Sound. Since 1982 it has retreated up its marine-grounded channel 12 km, thinned as much as 400 m in the terminus region (lowest 10 km), and maintained sustained annually-averaged flow speeds in excess of 25 m/day (9 km/year), making it presently the world's fastest glacier. Calving flux has increased along with flow velocity, rising  from 1 km/yr prior to the onset of retreat to a present value of 8 km/yr. Retreat has been accompanied by activation of fast flow far upglacier, beyond the limits of the marine-grounded channel.
PARAGRAPH_XXO The retreat of Columbia Glacier has been documented by aerial photography and photogrammetric analysis, starting in 1974 and continuing to the present, with 124 photo flights made to date. Photogrammetric analysis of the photography gives 3-D positions of trackable features to 0.3 m accuracy and highly detailed sub-annual velocity and strain rate fields.
PARAGRAPH_XXO Following the pattern of Alaska's other major tidewater glaciers, retreat can be expected to continue until the terminus retreats to a position in the channel grounded at or above sea level -  a point approximately 20 km upglacier from the present terminus. Retreat to this point requires removal of ca. 80 km^3 of ice. The present ice flux at the terminus is approximately 20 km^3/yr; this flux will be diminished in the future by declining thickness, although declining thickness may be partly offset by increasing flow velocity. Three simple estimates of retreat predict that the terminus will retreat to the head of the marine-based channel in 9 - 12 years. 
PARAGRAPH_XXO Present observations and uncertainties raise several important and unanswered questions:
PARAGRAPH_XXO 1. What better estimate can be made for future retreat? The present estimate of 9 - 12 years is based only on bounding assumptions about flow velocity and calving. Accurate numerical modeling is difficult in this situation because of the critical and essentially unknown basal sliding boundary condition and the likely important role of longitudinal coupling.
PARAGRAPH_XXO 2. What will be the fate of calved ice? Most calved ice is presently held in the channel by the moraine shoal created by the advance of Columbia Glacier to its extended position (attained in the early 19th century and held until 1982). This shoal prevents most ice from floating out into Prince William Sound and into tanker shipping lanes. Erosion of the shoal by icebergs could allow larger and substantially greater numbers of icebergs into the Sound, threatening shipping. Conversely, the impounded floating ice is known to support significant horizontal stresses, and increased iceberg densities resulting from increased iceberg flux may create backstresses which help stabilize the glacier terminus.
PARAGRAPH_XXO 3. How are calving and flow related? This critical question remains unanswered. Neither the calving process itself nor the cause-effect relation (if any) between calving and flow are at known with any degree of confidence; present viewpoints range from calving controlling near-terminus dynamics and terminus position to calving being simply dictated by conditions on unsupported ice cliff height at the terminus. A knowledge of calving/flow interactions is needed not only for predictive understanding of tidewater glacier retreat but also for insight into the dynamics of marine-based ice sheets such as West Antarctica.
PARAGRAPH_XXO 4. How were upglacier regions of Columbia Glacier activated by changes in conditions at the terminus at the start of retreat? Whether calving controls dynamics or vice versa, it is at least evident that accelerated flow appeared first in the vicinity of the calving front and subsequently propagated far upglacier, even activating a previously stagnant tributary. This propagating influence extended far beyond the reach of changes in local thickness and slope, and was presumably accomplished through long-range coupling in subglacial hydrology. This question relates directly to the larger - and also poorly understood - problem of glacier sliding, and like calving, has a bearing on ice sheet as well as temperate glacier dynamics.

INSERT_PAGE_BREAK_HERE
TITLE_XXO YANA/RHS SITE: GEOLOGY, STRATIGRAPHY, DATING, AND ARCHAEOLOGY.

AUTHORS_XXO PITULKO, VLADIMIR V. (1); Anisimov, Mikhail A. (2); Basilyan, Alexander E. (3); Giria, Evgeny Yu. (4); Nikolsky, Pavel A. (5); Odess, Daniel (6); Pavlova, Elena Yu. (7); Tumskoy, Vladimir E. (8)

AUTHOR_1_XXO (1) Institute for the History of Material Culture, RAS; archeo@archeo.ru
AUTHOR_2_XXO (2) Arctic and Antarctic Research Institute
AUTHOR_3_XXO (3) Institute for Geology, RAS
AUTHOR_4_XXO (4) Institute for the History of Material Culture, RAS
AUTHOR_5_XXO (5) Institute for Geolgoy, RAS
AUTHOR_6_XXO (6) University of Alaska Museum
AUTHOR_7_XXO (7) Arctic and Antarctic Research Institute, RAS
AUTHOR_8_XXO (8) Moscow State University

PARAGRAPH_1_XXO During a recent survey by the ZHOKHOV 2000 project, a locality where geologist Mikhail Dashtseren found a foreshaft made of woolly rhinoceros horn in 1996 was revisited to assess its research potential. The site is located on the left bank of the Yana River about 100km south of its’ entrance into the Laptev Sea (73º NL). At 879km. in length, the Yana River is one of the largest river systems in North Eastern Siberia. It drains a basin of 238,000sq.km, most of which is located north of the Polar Circle, and is a true Sub-Arctic and Arctic environment. A radiocarbon assay of the foreshaft suggests that the site could be 27,000 years old. This paper describes the results of the work conducted during this visit and proposes that the site, now called Yana/RHS (the Rhinoceros Horn Site) is the earliest archaeological site yet found in the part of the world 
PARAGRAPH_XXO Until recently, archaeological work has only been conducted in the southern portion of the Yana basin (Scherbakova, 1980; Mikhalev & Eliseev, 1992). From their research, they concluded that the Upper Yana was permanently populated only since the middle Holocene. Although a possibility for even earlier timing of the initial population of the Yana was suggested by Mochanov (1977), Scherbakova (1980), and by Mikhalev and Eliseev (1992), until now there is no solid evidence for a pre-Holocene human occupation of this part of Siberia. Even in Indighirka basin some 500 km., to the east of the Yana, the evidence for a late Pleistocene human occupation is questionable at best.
PARAGRAPH_XXO At the Yana/RHS site the cultural material (fragmented/broken bones of Pleistocene animals and lithic artifacts) were located in several exposures along the riverbank. A preliminary description of the exposures was done for a distance of 1.6 km upstream from the point where the first artifact was found (fig. 1). Two well-marked orographic levels can be seen in the along this section. The first is about 15 m high. It is under its scarps that all of the artifacts were found. The second one is about 36 m high. The upper part is represented by an ice complex, while the lower one is formed by sandy loams and sand with aleurit filler that is characterized by irregular bedding. The sandy loam horizon can be traced along the whole length of the bank and seems to be a single layer. The transition to the ice complex is gradual and has many facies. It was noted that on the level of about 20 m above the water line the ice complex has multiple interbeds, enriched with organic materials (peat and plant remains). A series of C-14 samples were taken to assess the ages of these deposits.
PARAGRAPH_XXO In the eastern part of the section the sandy loam horizon is overlain with a complex alternation of loam, sandy loam, peat and organic layers that include fragments of wood that are up to 40 cm in diameter. Due to intensive solifluction it was impossible to trace the transition from the lower horizon to the upper one. Samples for dating were taken from the upper horizon on the level of 8-8.9m and 12 m from the water line. The upper samples come from a peat layer that reaches 15 cm thick.
PARAGRAPH_XXO Stripping of a small protruding cape was done in direct proximity to the site on the level of the water line. In its sidewall was an unclear horizon (50 cm thick) with a high organic content. A piece of wood was taken from this horizon for radiocarbon dating. This organic layer rested on a sandy horizon saturated with pebbles.
PARAGRAPH_XXO Archaeological material came from six loci, not including the place where the foreshaft was found. Altogether over 150 artifacts were collected, most made of a silicified slate.
PARAGRAPH_XXO It should be noted that a low area near the western edge of the thermocirque proved to be the most interesting and rich area of the site (fig 1). Over a half of all the artifacts were collected here, as well as a considerable number of broken animal bones.
PARAGRAPH_XXO The lithics found at the site can generally be described as a pebble industry. Pebble industries are very common in the Siberian Paleolithic, however, this does not mean that we suggest any analogies for the materials discovered at Yana. In general, the Yana industry is a combination of both unifacial and bifacial flaking of silicified slate pebbles as well as artifacts made from quartz crystal. The major tool types include choppers, pointed bifaces (knives and backed knives), side and angle-scrapers, points and chisel-like tools.
PARAGRAPH_XXO Although nearly 300 faunal specimens were collected at the site, only a few were found associated with the artifacts. Among the animal species represented by the bones were reindeer, horse, mammoth, bison, musk ox, polar fox, wolf, and birds.
PARAGRAPH_XXO Four conventional radiocarbon dates have been obtained for the site. Bones for dating had been collected from spots where they were concentrated on the areas of about 0.5 sq.m.  Dates were run by Leopold D. Sulerzhitsky at the Institute for Geology, RAS. These dates are in agreement with the AMS date run on the foreshaft and suggest that the site is around 27,000 years old.
PARAGRAPH_XXO We stress that the significance of the Yana/RHS site is that this is the earliest evidence of human occupation north of 71º degrees NL, and the first evidence that humans inhabited the Eastern Siberian Arctic during the last interglacial. Future in-depth research is planned at the site and will no doubt provide additional evidence for the earliest high latitude human adaptation. 

REFERENCE_XXO Mikhalev, V.M., and E.I. Yeliseyev.  Archaeological survey in the Upper Yana River. In Yu.A.Mochanov (Ed.) Archaeological Research in Yakutia. Novosibirsk. Nauka. 1992: 47 -- 64. In Russian
REFERENCE_XXO Mochanov, Yu.A. 1977. The Oldest Stages Human Occupation in  Northeastern Asia. Novosibirsk. Nauka. 1977. 236pp. In Russian
REFERENCE_XXO Scherbakova, N.M. 1980. Archaeological sites on the Yana River. In Yu.A.Mochanov (Ed.) Novoye v arkheologii Yakutii. Yakutsk. Yakutsk State Univ.1980: 62 -- 65. In Russian

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/75-1.jpg

CAPTION_XXO Fig 1.  

INSERT_PAGE_BREAK_HERE
TITLE_XXO CONTRASTING GLACIAL GEOLOGY OF THE STRANDIR AND ISAFJARDARDJUP COASTLINES, NW PENINSULA, ICELAND

AUTHORS_XXO PRINCIPATO, SARAH M. (1); Geirsdottir, Aslaug (2); Andrews, John T. (3)

AUTHOR_1_XXO (1) INSTAAR and Dept. of Geological Sciences; University of Colorado; principa@stripe.colorado.edu
AUTHOR_2_XXO (2) University of Iceland; age@rhi.hi.is
AUTHOR_3_XXO (3) INSTAAR and Dept. of Geological Sciences; University of Colorado; andrewsj@spot.colorado.edu

PARAGRAPH_1_XXO Terrestrial fieldwork is in progress to address questions regarding ice extent and glacial history for part of the Northwest Peninsula (NWP) of Iceland during the last glacial maximum and through the deglaciation and the Holocene.  Radiocarbon dates on foraminifera above diamicton units in marine cores offshore in Hunafloaall suggest that ice retreated from the shelf by approximately 13ka, and there is abundant ice-rafted debris in marine cores from the Reykjarfjordur region until approx. 9.1-9.5ka (Andrews et al. 2000; Castaneda, 2001).  This suggests that ice was calving into the fjord until the early Holocene.  Detailed geomorphic mapping is being completed along the Strandir coast and the eastern side of the Isafjardardjup coast to determine the Late Quaternary and deglacial history on land, and correlate it with the marine core chronology.  Cosmogenic exposure dating, radiocarbon dating, tephrachronology, and morphostratigraphic relationships are combined to determine the terrestrial chronology.
PARAGRAPH_XXO The glacial geology of the Strandir coast is dominated by erosive glacial landforms.  Steep peaks, horns, and arêtes, have elevations up to approximately 800m asl.  Striated bedrock surfaces are abundant along the Strandir coast, but glacial sediment deposits are minimal.  In contrast, the eastern Isfjardardjup coast contains moraines in front of active outlet glaciers of the Drangajokull Icecap in Kaldalon and Leirufjordur, as well as a large moraine in the Sela river valley.  The ages of these moraines are unknown, and a large moraine at the head of Kaldalon is especially dubious.   Boulders on the crest of these moraines were collected for cosmogenic exposure dating, and dates are pending.  Behind the large moraine in Kaldalon, at least 4 younger moraines are present.  A stratigraphic section is located in a stream cutbank eroding through a grassy, subdued moraine approx. 1km behind the large moraine at the head of Kaldalon.  Alternating layers of peat, diamicton, and sand present in this section may be interpreted as fluctuations between landscape stability and glacial advances.  Buried wood found in the section at a depth of 265cm has a radiocarbon date of 3328+/- 45 14C years, and the base of the peat section has a date of 2503+/-59 14C years.  Subsequent peat samples have been submitted to confirm the minimum age of this moraine.  Behind this subdued, vegetated moraine a steeper, gravely moraine is present, which is probably Little Ice Age.  Lichenometry measurements of Rhizocarpon gr. geographicum on the less well vegetated moraines in Kaldalon provide relative ages of the glacier fluctuations during the past few hundred years.  
PARAGRAPH_XXO The marine limit in the study area varies from approximately 30m a.s.l. in the northwest to approximately 45m. in the southeast.  The large moraine at the head of Kaldalon lies behind/ up valley from the marine limit, so it is possibly early Holocene in age.  However, there is no direct stratigraphic overlap between the moraine and marine/beach sediments in this valley.  In the next valley south of Kaldalon, gravels drape over a small ridge of diamicton, but no organic material was found for dating.  Mollusk shells were present in a raised beach terrace north of Kaldalon, approximately 7m above sea level, and yield a radiocarbon date of 3612+/- 40 14C years.  
PARAGRAPH_XXO An 8cm thick basaltic ash unit surrounded by peat layers is located in the southwestern portion of the study area (Principato, 2000).  Geochemistry, color, grain size, and a radiocarbon date of 9081+/- 68 14C years on peat below the ash confirm that this unit is the Saksunarvatn Ash.  This tephra facilitates a link between the terrestrial and marine environments, as it is present in several marine cores from NW Iceland.  This tephra was not found along the eastern Isafjardardjup coastline, although it is present in marine cores in Isafjardardjup and lake cores in Efstadalsvatn (Geirsdottir et al. in subm).  It is possible that the tephra deposits have been eroded away from the eastern Isafjardardjup coast or covered by colluvium, but it also might mean that this area was still ice covered when the Saksunarvatn was deposited.  Future field investigations are needed to determine the extent of this tephra in the northern part of the study area.              

REFERENCE_XXO Andrews, J. T., Hardardottir, J., Helgadottir, G., Jennings, A. E., Geirsdottir, A., Sveinbjornsdottir, A. E., Schoolfield, S., Kristjansdottir, G. B., Smith, L. M., Thors, K., and Syvitski, J. P. M., 2000, The N and W Iceland Shelf: Insights into Last Glacial Maximum Ice Extent and Deglaciation based on Acoustic Stratigraphy and Basal Radiocarbon AMS dates. Quaternary Science Reviews, v. 19, p. 619-631.
REFERENCE_XXO Castaneda, I., 2001., Holocene paleoceanographic and climatic variations of the inner north Iceland continental shelf, Reykjarfjordur area, MSc Thesis, Univ. of Colorado, Boulder.
REFERENCE_XXO Geirsdottir, A., Andrews, J.T., Olafsdottir, S., Helgadottir, G., and Hardardottir, J., in subm, A 35ka record of iceberg rafting from NW Iceland: following the ice retreat from shelf to land. Polar Research.
REFERENCE_XXO Principato, S.M., 2000, The glacial geology of Reykjarfjordur, NW Iceland. Geological Society of America Program with Abstracts, vol. 32, no. 7.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/25-1.jpg

CAPTION_XXO Fig 1.  Location of study area.

INSERT_PAGE_BREAK_HERE
TITLE_XXO A PERMAFROST WATER BALANCE MODEL FOR THE ARCTIC: MODEL RUNOFF AND DISCHARGE VALIDATION SITES

AUTHORS_XXO RAWLINS, MICHAEL A. (1); Lammers, Richard B. (2); Shiklomanov, Alexander (3); Vorosmarty, Charles J. (4)

AUTHOR_1_XXO (1) Water Systems Analysis Group, University of New Hampshire, Durham, NH USA; michael.rawlins@unh.edu
AUTHOR_2_XXO (2) Water Systems Analysis Group, University of New Hampshire, Durham, NH USA; richard.lammers@unh.edu
AUTHOR_3_XXO (3) Water Resources and River Estuaries Department, Arctic and Antarctic Research Institute, St. Petersburg,Russia; alex.shiklomanov@unh.edu
AUTHOR_4_XXO (4) Water Systems Analysis Group, University of New Hampshire, Durham, NH USA; charles.vorosmarty@unh.edu

PARAGRAPH_1_XXO The Arctic terrestrial hydrologic cycle, through its influence on the Arctic Ocean, is an important aspect of high-latitude Earth systems research. Given the possibility of considerable warming under several global-change scenarios, monitoring of the terrestrial Arctic hydrology has become increasingly important to identify significant anomalies, as well as to establish baseline contemporary conditions upon which future changes can be measured.  A key component in a systemic monitoring of Arctic hydrology is land-surface models which can accurately capture the temporal and spatial variability of the water cycle from readily available input drivers such as air temperature and precipitation.  Our model also incorporates spatially-explicit fields of vegetation type and rooting depth, soil properties, and routing of river water to the ocean. 
PARAGRAPH_XXO The land surface water budget model is a daily model which contains a simple snowmelt routine, a two layer soil component for root zone and deep soil, and active layer thaw based on an air temperature degree day approach. Use of this simple method to define soil moisture thawing and freezing enables the water budget model to be run without input of a priori active-layer depths. Fields of daily precipitation and air temperature, modified from NCEP re-analysis products, are used to drive the model from 1980-2001.  Local runoff surfaces and other spatial fields are estimated over the entire pan-Arctic domain.
PARAGRAPH_XXO Observational ArcticRIMS discharge sites--obtained in real time--currently number 57 stations (16 in Russia, 10 in Canada, 19 in USA, and 12 in Norway). In total they cover a drainage area of 13.2 million sq. km, which is equivalent to 63% of total non-ice covered land area of the pan-Arctic or 79% of total Arctic Ocean drainage (not including Hudson Bay drainage and Greenland).  The data for these gauges are supplied as provisional data, which means that normal adjustments to the data by the respective national agencies has not been implemented.  Data is collected daily from the USGS and Environment Canada and weekly from Russia.  This effort builds upon an existing pan-Arctic river discharge database, R-ArcticNET available over the Internet (http://www.R-ArcticNET.sr.unh.edu/) or on CD via the National Snow and Ice Data Center, Boulder, CO, USA.

INSERT_PAGE_BREAK_HERE
TITLE_XXO RECENT PERMAFROST MELT IN PEATLANDS OF NORTHWESTERN CANADA

AUTHORS_XXO ROBINSON, STEPHEN D. (1); Park, Joe (2)

AUTHOR_1_XXO (1) St. Lawrence University; srobinson@stlawu.edu
AUTHOR_2_XXO (2) GDT Canada; joe_park@gdt1.com

PARAGRAPH_1_XXO The presence or absence of permafrost is an extremely important control on rates of carbon storage in peatlands (Camill, 1999; Robinson and Moore, 2000).  Most studies that suggest that a climate warming will result in a net carbon source to the atmosphere through increased decomposition are from sites with continuous permafrost.  The response of carbon pools in the discontinuous permafrost zone may be more complicated as peatland-permafrost relationships are influenced more by vegetation patterns and hydrology, and result in peat landforms with significantly different rates of carbon storage (Robinson and Moore, 1999).
PARAGRAPH_XXO The Mackenzie Valley, Northwest Territories, is one of the major peatland regions in Canada, yet it remains relatively unstudied by researchers.  Peatlands cover approximately 15% of the Mackenzie Valley north of 60oN, but with large areas approaching 100% peat cover.  Permafrost conditions range from sporadic discontinuous in the southern part of the valley, extensive between approximately 62 and 64oN, and continuous north of 64 or 65oN.  The region is also characterized by low precipitation and is affected by a significant number of wildfires.
PARAGRAPH_XXO Around and south of Fort Simpson, peatlands are a dominant component of the landscape.  Permafrost temperatures in peatlands of this area are only slightly below 0oC (Robinson and Moore, 2000).  This region of discontinuous permafrost adds an important and dynamic complication to the question of carbon storage, and much of this permafrost is expected to melt with only a slight warming (Wright et al., 2000).  A significant warming trend is noted in climate records for both Fort Simpson and Norman Wells, and the Mackenzie Valley region has undergone the most warming of any region in Canada over the past century (data from Environment Canada).
PARAGRAPH_XXO The delineation of frozen and unfrozen peatland areas is relatively simple using aerial photographs and some forms of satellite imagery. In general, frozen peatlands are forested and appear dark on photographs, while unfrozen regions are of lighter tones. Utilizing imagery collected over a long time span, combined with GIS analytical techniques, allows the calculation of recent rates of thaw.  We used a time-series of aerial photographs and high-resolution satellite images spanning at least 50 years to quantify thaw at four locations (total 6 sites) ranging in latitude from 60 to 64oN.
PARAGRAPH_XXO Significant thaw of permafrost has occurred at all sites over the past 50 years, ranging from a 33.9 to 79.2% increase in unfrozen peatland area.  On average, the amount of thawed peatland increases by 1% per year in this region.  There is a trend of lesser increases in thawed area with increasing latitude.  Mean lateral thaw (the lateral movement of the frozen - unfrozen boundary) at different sites ranges from 7.0 to 18.6 m over the time period of study.  This translates into a range of 0.127 to 0.351 m per year over the 50-55 years of study.  Maximum thaw rates reach over 1.0 m per year at several sites.  There are also locations at the Liard site (61o 26’N) where very large peat plateaus, up to 200 x 225 m have completely thawed in the 53 years between images. Overall, there are significant ranges in retreat rates, with some margins retreating as much as 45 m, and some showing no retreat or even minor permafrost aggradation, however the general trend is towards significant, widespread permafrost thaw in peatlands of the southern Mackenzie Valley.
PARAGRAPH_XXO Many of the thawed areas at the Liard River sites are becoming more and more interconnected and contiguous over time, resulting in improved drainage and a decrease in the dominance of permafrost.  A result of the dominance of unfrozen peatlands and improved drainage is the establishment of drier, shrub and tree-dominated non-permafrost peatlands that have higher carbon accumulation rates than permafrost-dominated sites.  In contrast, sites other than the Liard River area are still permafrost-dominated, although the trend is certainly towards ongoing thaw, the coalescence of thaw features, the development of an integrated drainage basin, and a landscape becoming more dominated by unfrozen peatlands.  These differences may be due to changing hydrological conditions associated with the loss of permafrost on a large scale.  Recent evidence from Camill (1999), combined with this assessment based on a time series of images, suggests that thaw features may follow a consistent succession pattern changing to drier, raised communities in as little as 50-80 years.  It is possible that high methane fluxes common following permafrost thaw may not be sustainable over the long-term, as the raised unfrozen communities have much lower fluxes (Liblik et al., 1997).

REFERENCE_XXO Camill, P. 1999. Peat accumulation and successsion in the boreal permafrost peatlands of Manitoba, Canada. Ecoscience 6, p. 592-602.
REFERENCE_XXO Liblik, L.K., Moore, T.R., Bubier, J.L., and Robinson, S.D. 1997. Methane emissions from wetlands in the zone of discontinuous permafrost: Fort Simpson, Northwest Territories, Canada. Global Biogeochemical Cycles, 11, p. 485-494.
REFERENCE_XXO Robinson, S.D. and Moore, T.R. 1999. Carbon and peat accumulation over the past 1200 years in a landscape with discontinuous permafrost, northwestern Canada. Global Biogeochemical Cycles, 13, p. 591-602.
REFERENCE_XXO Robinson, S.D. and Moore, T.R. 2000. The influence of permafrost and fire upon carbon accumulation in high boreal peatlands, Northwest Territories, Canada. Arctic, Antarctic and Alpine Research, 32, p. 155-166.
REFERENCE_XXO Wright, J.F., Smith, M.W., and Taylor, A.E. 2000. Potential changes in permafrost distribution in the Fort Simpson and Norman Wells regions. Pages 197-207 in L.D. Dyke and G.R. Brooks, eds. The Physical Environment of the Mackenzie Valley, Northwest Territories: a Baseline for the Assessment of Environmental Change. Geological Survey of Canada Bulletin 547, p. 197-207. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO LONG DISTANCE POLLEN TRANSPORT OVER GREENLAND

AUTHORS_XXO ROUSSEAU, DENIS-DIDIER (1); Jolly, Dominique (2); Duzer, Danielle (3); Cambon, Genevieve (4); Ferrier, Jackie (5); Gros, Robert (6)

AUTHOR_1_XXO (1) CNRS-Universite Montpellier II; denis@dstu.univ-montp2.fr
AUTHOR_2_XXO (2) Universite Montpellier II; jolly@isem.univ-montp2.fr
AUTHOR_3_XXO (3) CNRS-Universite Montpellier II; duzer@isem.univ-montp2.fr
AUTHOR_4_XXO (4) CNRS-Universite Montpellier II; cambon@isem.univ-montp2.fr
AUTHOR_5_XXO (5) CNRS-Universite Montpellier II; ferrier@isem.univ-montp2.fr
AUTHOR_6_XXO (6) CNRS-Universite Montpellier II; gros@isem.univ-montp2.fr

PARAGRAPH_1_XXO This paper concerns the preliminary results of an on-going project to survey the present pollen rain of the Greenland atmosphere by distinguishing the pollen grains produced by the local tundra vegetation, relatively few diversified, to exotic pollen originated from other regions such as North America. First, soil surface samples mainly record the pollen production of the local tundra vegetation although one of them shows the presence of oak, which is exotic to Greenland. Second, a pollen collector installed at Kangerlussuaq, on the West Coast of Greenland, nearby a meteorological station, shows that the vegetative season is restricted only to 9 weeks. The comparison with other records, especially from more temperate area characterizes the adaptation of plants to arctic conditions. Furthermore the recognition of exotic pollen such as cereals, hackberry, vine, olive, oak, sycamore and pine in a region where only short tundra vegetation grows clearly demonstrates that there are really inputs of exotic pollen probably originated from various regions of North America.

INSERT_PAGE_BREAK_HERE
TITLE_XXO RECENT FORAMINIFERA OFF NORTH AND WEST ICELAND

AUTHORS_XXO RYTTER, FRANK (1); Jennings, Anne  E. (2); Seidenkrantz, Marit-Solveig (3); Knudsen, Karen Luise (4); Eiriksson, Jon  (5)

AUTHOR_1_XXO (1) Department of Earth Sciences, University of Aarhus, Dk-8000 Aarhus C, Denmark; frank.rytter@geo.au.dk
AUTHOR_2_XXO (2) INSTAAR and Department of Geological Sciences, University of Colorado, Boulder, CO 80309-0450, USA
AUTHOR_3_XXO (3) Department of Earth Sciences, University of Aarhus, Dk-8000 Aarhus C, Denmark
AUTHOR_4_XXO (4) Department of Earth Sciences, University of Aarhus, Dk-8000 Aarhus C, Denmark
AUTHOR_5_XXO (5) Science Institute, University of Iceland, IS-101, Reykjavik, Iceland

PARAGRAPH_1_XXO The surface ocean circulation around Iceland is influenced by both cold and warm water masses: the warm Irminger Current (IC), the polar East Greenland Current and the modified polar water of the East Icelandic Current (EIC). A relatively complex oceanography also characterise the sea-bed of the North and West Iceland shelves, which is subjected to the interaction of three separate water masses: IC Water, Arctic Intermediate Water (AIW) and Norwegian Sea Deep Water (NSDW). This makes the area useful for the study of benthic foraminiferal species in relation to bottom water characteristics such as temperature and salinity, as well as to primary production and water depth.
PARAGRAPH_XXO Already in 1945, Norvang showed a connection between modern, benthic foraminiferal faunas and the water-mass distribution in Iceland waters. In order to further the understanding of the environmental requirement of the benthic foraminifera in the region, we have analysed 69 surface-sediment samples from water depths ranging between 34 and 1000 m from off West and North Iceland and compared the faunal distribution with a number of environmental parameters.
PARAGRAPH_XXO The south-western Iceland shelf is swept by warm Atlantic Water of the IC, and the assemblages are dominated by Uvigerina mediterranea, Hyalinea balthica, Trifarina angulosa and Cassidulina laevigata. As salinities and temperatures decrease towards the north, these species loose importance.
PARAGRAPH_XXO With the exception of the shallower regions, the shelf and slope area of North Iceland may faunistically be divided into a western and an eastern part with the submarine Kolbeinsey Ridge forming a shallow barrier on the northernmost part of the north Icelandic shelf. Only in the southern part of the shelf, which is influenced by the IC, the faunal composition is relatively uniform. This area is characterised by Cassidulina neoteretis and Melonis barleeanus, although Astrononion gallowayi, Cibicides spp., Elphidium spp. and Trifarina fluens dominate the relatively high-energy areas of the coastal region.
PARAGRAPH_XXO Further north in the AIW region, the western side of the Kolbeinsey Ridge is dominated by M. barleeanus and Nonionellina labradorica, with T. fluens, Islandiella norcrossi, Globobulimina auriculata arctica and Pullenia bulloides as accessory species. Nonionellina labradorica is especially common in an area with higher primary productivity connected to the oceanic front between the IC and the EIC. East of the ridge, T. fluens and Adercotryma glomerata dominate. In contrast to N. labradorica, T. fluens has an inverse relationship with organic carbon content.
PARAGRAPH_XXO The NSDW influences the deeper part of the North Iceland shelf and slope. Calcareous species prevail in the western part, while agglutinated foraminifera dominate the eastern part. On the western side of the ridge, M. barleeanus is consistently a dominant species, although C. neoteretis, T. fluens, I. norcrossi and P. bulloides are also relatively common. Agglutinated foraminifera are mainly represented by Paratrochammina spp. and Saccammina difflugiformis. On the eastern side of the Kolbeinsey Ridge, the NSDW region is highly dominated by agglutinated foraminifera, especially S. difflugiformis. Melonis barleeanus is the only common calcareous species.

INSERT_PAGE_BREAK_HERE
TITLE_XXO POLLEN TRAP STATIONS: MODERN ANNUAL DEPOSITION AND AERIAL POLLEN TRANSPORT IN THE LENA RIVER DELTA 

AUTHORS_XXO Savelieva, Larissa A. (1); Dorozhkina, Marina  V. (2); PAVLOVA, ELENA YU. (3)

AUTHOR_1_XXO (1) 1Geographical Research Institute of St. Petersburg State University; savelieval@mail.ru
AUTHOR_2_XXO (2) State Research Center of Russian Federation Arctic and Antarctic Research Institute; mdorozhkina@mail.ru
AUTHOR_3_XXO (3) State Research Center of Russian Federation Arctic and Antarctic Research Institute; bunge@mail.ru

PARAGRAPH_1_XXO Studies of the annual pollen and spore deposition in different areas of the Lena River delta were undertaken for the first time in the Asian sector of the Arctic during the Russian-German “Lena-98” and “Lena-99” expeditions in the framework of the International “Laptev Sea System-2000” Project. To achieve this objective, three spore-pollen traps were set up along the meridional delta profile in accordance with the European Pollen Monitoring Programme for the period July 1998 to August 1999 (Pavlova & Dorozhkina 1999, 2000). A comparison between the results of spore-pollen analysis of the contents of traps and the surrounding vegetation was performed. 
PARAGRAPH_XXO The results of the executed study have confirmed the conclusion that the current spore-pollen spectra are comprised both of pollen and spores of the local plants and of long-distance pollen and spores (Kalugina 1979).
PARAGRAPH_XXO The pollen of tree plants within the Lena River delta is long-distance and does not reflect the character of the local vegetation.  The pollen influx of tree species depend on the wind regime character of the territory, location of the northern boundary of the tree species development areas and the morphological pollen structural features. 
PARAGRAPH_XXO The dependence of the long-distance pollen deposition on the character of the wind regime of the region was established.
PARAGRAPH_XXO The character of the wind regime accounts primarily for the decreasing concentration of the tree plant pollen from south to north of the delta. The prevailing southerly and southeasterly wind direction determines the main pollen influx of tree species from the areas of their growth south of the delta.  The pollen of shrubs in the traps is both long-distance and local. 
PARAGRAPH_XXO The detected pollen corresponds to a great extent to the character of local vegetation in general. However, the deposited pollen concentrations do not reflect quite accurately the composition of dominating species.
PARAGRAPH_XXO For the long-distance shrub pollen, the dependence on the wind regime is also established. 
PARAGRAPH_XXO The pollen of herbaceous plants is local reflecting to the greatest extent the character of the local vegetation cover.
PARAGRAPH_XXO The distribution of the deposited pollen assemblages among the different families of herbs corresponds to the plants dominating in plant communities of the study areas.
PARAGRAPH_XXO The features of the morphological structure and fossilization of pollen and the features of the productive capability and plant growing conditions are of large significance in the pollen transfer and deposition.

INSERT_PAGE_BREAK_HERE
TITLE_XXO OBSERVATION OF SEA ICE PROPERTIES AND ARCTIC CLIMATE VARIABILITY USING MICROWAVE REMOTE SENSING DATA: THE COLLABORATIVE INTERDISCIPLINARY CRYOSPHERIC EXPERIMENT (C-ICE)

AUTHORS_XXO SCHARIEN, RANDALL K. (1); Yackel, John J. (2); Barber, David G. (3)

AUTHOR_1_XXO (1) University of Calgary; rkschari@ucalgary.ca
AUTHOR_2_XXO (2) University of Calgary; yackel@ucalgary.ca
AUTHOR_3_XXO (3) University of Manitoba; dbarber@ms.umanitoba.ca

PARAGRAPH_1_XXO The sensitivity of Arctic regions to climate change scenarios is well documented. This sensitivity is primarily driven by a positive albedo-feeback linkage between sea ice and albedo. Sea ice plays a critical role in the exchange of heat and moisture between the ocean and atmosphere by acting as a 'skin' that, when snow covered, reflects approximately 85% of incident solar radiation. As such, observed reductions in total sea ice extent and thickness (e.g., Cavalieri et al., 1997; Rothrock et al., 1999) have implications for affecting the climate state of the Arctic. Microwave remote sensing has proved to be an effective tool for studying and monitoring large-scale Arctic sea ice processes.  
PARAGRAPH_XXO The Collaborative Interdisciplinary Cryospheric Experiment (C-ICE) is an annual field experiment that has evolved from research relating to four general themes: i. sea ice energy balance; ii. numerical modeling of atmospheric processes, iii. remote sensing of snow covered sea ice; and iv. ecosystem studies. It is comprised of many individual projects within a core sampling program. The goal of the core sampling program is to capture accurate and precise long-term data to detect changes that may be occurring in the Arctic marine system. The C-ICE experiment, combined with previous SIMMS field experiments, provides over a decade of comprehensive data collection in the Arctic.
PARAGRAPH_XXO  The C-ICE field experiment provides sea ice surface data required to understand and model the process linkages operating in an environment typical of fast-ice conditions Canadian Arctic Archipelago (Barber and Iacozza eds., 1999). Field data is integrated with numerical models of primary processes in the study region, for the expressed purpose of 'scaling up' observations to more regional scales. This 'scaling up' of observations allows for the integration of microwave remote sensing data for the inversion of surface geophysical characteristics. Currently, the C-ICE project includes the collection of micrometeorological data (i.e., relative humidity, air temperature, wind speed and direction, solar and longwave radiation, etc.), cloud observations (i.e., height, visual observations, occurrence of precipitation), snow and sea ice physical and morphological characteristics and distribution, melt pond evolution, biological data (i.e., ice algae, water column, sedimentation), and remotely sensed imagery (i.e., RADARSAT-1 imagery, surface-based radiometry, and paraglider video data).   
PARAGRAPH_XXO This paper summarizes the principal driving themes of the C-ICE experiment, as well as past, current, and future projects conducted within it. In particular, the utilization of microwave remote sensing data with C-ICE field data is reviewed.    

REFERENCE_XXO Barber, D.B. and J. Iacozza (eds.). C-ICE 1999 Field Summary. CEOSTEC-99-1-1 (Winnipeg, Manitoba, 1999). 
REFERENCE_XXO Parkinson, C.L., D.J. Cavalieri, P. Gloersen, H.J. Zwally and J.C. Comiso. 1999. Arctic sea ice extents, areas, and trends, 1978-1996. J. Geophys. Res. 92: 7049-7059.
REFERENCE_XXO Rothrock, D.A., Y. Yu and G.A. Maykut, 1999. Thinning of Arctic sea ice cover. Geophys. Res. Lett. 26: 3469-3472.

INSERT_PAGE_BREAK_HERE
TITLE_XXO ADAPTIVE STRATEGY OF DENNING POLAR BEARS IN WESTERN HUDSON BAY

AUTHORS_XXO SCOTT, PETER A.

AUTHOR_1_XXO Churchill Northern Studies Centre; pascott@interhop.net

PARAGRAPH_1_XXO Polar bears spend most of their life on the polar sea ice. At the southern edges of the arctic, populations are found on land during the period when the ice is melting or absent. The western Hudson Bay population has traditionally been without sea ice for approximately 100 days each year during which time the bears fast to conserve energy. Because of the summer fast, the birth and primary development of young polar bears requires at least 8 months of fasting by a female every two or three years. During the 1970s and 1980s the bears of western Hudson Bay were found to be the most productive known and yet they hunted for 100 days less than bears of northern populations did each year. The advantage of food quality or quantity is not justified as the diets are similar, the bears are of similar size, and the bear populations are at similar size and density. This indicates that energy conservation during the maternity period is a critical factor in the productivity of a population. Perhaps one advantage is the noted difference in den selection. While most polar bears den on the sea ice or nearby shore, western Hudson Bay bears den in frozen peat banks found in the riparian habitats south of Churchill, Manitoba, Canada. The author monitored temperature conditions in an assortment of these dens during the fall/winter maternity period. In addition, dens dug in gravel and snow were monitored to examine the differences in temperature. In winter, the peat dens were the same temperature as the surrounding permafrost (-2C) while snow and gravel dens were found to be colder. The past high productivity of the western Hudson Bay population appears to be, in part, because of the use of peat dens as a reproductive strategy.

INSERT_PAGE_BREAK_HERE
TITLE_XXO LONG-TERM VARIABILITY OF THE PAN-ARCTIC HYDROLOGICAL BUDGET AND THE DECLINE IN HYDROLOGICAL MONITORING NETWORKS

AUTHORS_XXO SHIKLOMANOV, ALEXANDER I. (1); Lammers, Richard B. (2); Vorosmarty, Charles J. (3); Peterson, Bruce J. (4); Holmes, Robert M. (5); McClelland, James W. (6)

AUTHOR_1_XXO (1) University of New Hampshire; Alex.Shiklomanov@unh.edu
AUTHOR_2_XXO (2) University of New Hampshire; Richard.Lammers@unh.edu
AUTHOR_3_XXO (3) University of New Hampshire; charles.vorosmarty@unh.edu
AUTHOR_4_XXO (4) Marine Biological Laboratory; peterson@mbl.edu
AUTHOR_5_XXO (5) Marine Biological Laboratory; rholmes@mbl.edu
AUTHOR_6_XXO (6) Marine Biological Laboratory; jmcclelland@mbl.edu

PARAGRAPH_1_XXO Russia, Canada, and the United States possess 92% of the non-ice covered pan-Arctic land area and contain the overwhelming majority of its monitoring stations. To estimate the current status of river discharge gauges across the pan-Arctic, data from the University of New Hampshire, the U.S. Geological Survey, the Water Survey of Canada, Environment Canada, and the Russian Hydrometeorological Service (Roshydromet) were used. The Arctic Ocean drainage basin is the best monitored in terms of freshwater flow to the coastal zone.  During the 1980s, when the number of stations reached its maximum, about 74% of the total non-glacierized pan-Arctic basin area was monitored. Even under such favorable conditions no measurements were taken in large regions of the basin ranging from 40% in North America to 15% in Russia. The total area monitored decreased to 67% from 1986 through 1999 at a rate of 79% in Russia and 51% in North America because some important downstream gauges located mainly on medium and small-sized rivers were closed. The total number of gauges is also an important index of our capacity to develop high-resolution mapping of contemporary runoff. This constitutes an essential tool for monitoring progress of climate change and for studying the overall hydrological response throughout the region. Over the last 15 years, the number of hydrologic gauges serving the pan-Arctic reverted to that of the early 1960s. There is a significant difference in the decline of discharge networks of various sub-regions across the pan-Arctic drainage. The network cutbacks were especially severe in the Far East of Siberia and the province of Ontario, where 73% and 67% of river gauges were closed between 1986 and 1999, respectively.
PARAGRAPH_XXO An analysis of long-term variations of river discharge, made based on datasets up to year 2000, shows a sustainable increasing trend for all regions of the pan-Arctic basin except the Hudson Bay watershed. The average rate of the increase in discharge to the Arctic Ocean was 3.6 km3/year (1.9 km3/year in Eurasia and 1.7 km3/year in North America) for 1936-2000. The rate is significantly higher (10 km3/year) for the period when global air temperature had a fast rise since 1976. Especially high values of river inflow to the ocean are observed since 1986. The mean annual discharge for 1986-2000 was about 200 km3/year greater than for 1936-85. Thus additional freshwater discharge for this period was 2800 km3.  This volume approximately equals the total annual inflow from Eurasia.  An integrated analysis of air temperature, precipitation and runoff was carried out for the 10 largest river basins representing a wide variation in geography. All these river basins show the air temperature increasing during last 10-20 years. The greatest runoff increase is observed for the large European rivers (Northern Dvina, Pechora) where it results from significant precipitation increase. The largest Siberian river basins, which have wide permafrost extent, demonstrate the increase in runoff despite no trend or a decreasing trend in precipitation.  It is likely the result of several components such as permafrost melting, a shorter winter period, an increase in ground water storage and a more rapid spring snow melt (such as the spring 2001 Siberian floods). Further research is going to be focused on water budget simulations for representative, undisturbed watersheds located in various climate regions to investigate the effect of global change on river runoff formation across the pan-Arctic drainage basin and river discharge to the ocean. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO PALEOECOLOGY OF NORTHWESTERN BERINGIA: RECONSTRCTION BASED ON MACROFOSSIL PLANT REMAINS FROM ZHOKHOV ISLAND, SIBERIA

AUTHORS_XXO SMITH, LEDA 

AUTHOR_1_XXO Center for Northern Studies / Middlebury College; lsmith@middlebury.edu

PARAGRAPH_1_XXO A buried peat deposit from Zhokhov Island (76°. 06'N, 152°.42'E, northeast of the New Siberian Islands chain, Russia) contains a variety of 
PARAGRAPH_XXO well preserved plant material. The calibrated radiocarbon dates for the 
PARAGRAPH_XXO sample indicate that it was deposited about 14,000 to 15,000 years ago 
PARAGRAPH_XXO (average calibrated radiocarbon age of  14, 410 BP [Beta Analytic]).  The sample thus represents a botanical assemblage from the Late Pleistocene of Northwestern Beringia. Identification and analysis of the plant macrofossils indicates that several vascular plant species occurred on Zhokhov at that time, but have since disappeared from the area. It is clear that the assemblage would be typical of a warmer environment than that which is current on Zhokhov Island. While this may indicate that the overall Late Pleistocene climate of the area was warmer (at least in summer) than at present, the interpretation is complicated by the radically changing shorelines in the region since the time of deposition of the plant remains. The island would have been larger and 
PARAGRAPH_XXO closer to the mainland, or may even have been part of the mainland, and 
PARAGRAPH_XXO thus subject to a more continental climate. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO HOLOCENE SEA-SURFACE CONDITIONS IN THE NORTH ATLANTIC - OPPOSITE W-E TRENDS (ICELAND BASIN VS. LABRADOR SEA).

AUTHORS_XXO SOLIGNAC, SANDRINE (1); de Vernal, Anne (2); Hillaire-Marcel, Claude (3)

AUTHOR_1_XXO (1) GEOTOP, Universite du Quebec a Montreal; solignac.sandrine@courrier.uqam.ca
AUTHOR_2_XXO (2) GEOTOP, Universite du Quebec a Montreal; devernal.anne@uqam.ca
AUTHOR_3_XXO (3) GEOTOP, Universite du Quebec a Montreal; chm@uqam.ca

PARAGRAPH_1_XXO Three sediment cores were used in order to compare Holocene sea-surface conditions in the eastern and western sectors of the northern North Atlantic. Cores P-094 (50°12.28' N, 45°41.15' W; 3448 m) and P-013 (58°12.59' N, 48°22.40' W; 3380 m) were collected in the Labrador Sea, near Orphan Knoll and on the Greenland rise, respectively, whereas core MD99-2254 (56º47,78' N, 30º39,86' W; 2240 m) was raised from the Bight Fracture zone area, east of the Reykjanes Ridge, in the Iceland basin. Stable isotope measurements on mesopelagic (Neogloboquadrina pachyderma left-coiling -Npl-) and epipelagic (Globigerina bulloides -Gb-) planktonic foraminifers, along with quantitative sea-surface temperature (SST) and sea-surface salinity (SSS) reconstructions using transfer functions based on organic-walled dinoflagellate cyst (dinocyst) assemblages, were used to document hydrographic changes during the Holocene. A special attention has been paid to changes in the upper water column structure (density gradients). Results illustrate opposite trends between the eastern (MD99-2254) and western (P-094 and P-013) sites, with respect to surface water salinity and density. SSS in cores P-094 and P-013 shows a strong increase during the Holocene with maximum values in the most recent part of the record. In contradistinction, it decreases slightly in core MD99-2254. The corresponding, salinity-driven changes in density, as illustrated by transfer function runs, are consistent with 18O shifts exceeding 0.5‰, that are depicted by both Npl and Gb, between ca.10 ka BP and the Present. In P-013 and P-094, d18O values increase, whereas, they decrease in MD99-2254. In contrast with SSS, SST trends in all cores are  not as clear, although a thermal optimum seems recorded at ca. 9-8 ka BP. Steadier temperature conditions are recorded, throughout the Holocene, in the eastern site vs. the western sector. In the latter case, relatively large amplitude oscillations are seen, jointly with a trend towards a lesser, late Holocene seasonal contrast. The specificity of the paleohydrography of the Iceland basin vs. Labrador Sea sites suggests a lesser variability of the North Atlantic Drift (NAD), that governs sea-surface conditions there, than of the cold East Greenland and Labrador currents, that influence sea-surface conditions in the western sites. The density changes that are reconstructed put constraints on thermohaline circulation changes, during the Holocene, notably on the respective rates of formation of deep waters, in the NE North Atlantic, vs. of intermediate waters, in the Labrador Sea. Relatively high density surface waters were present at the beginning of the Holocene, in the Iceland basin, suggesting a enhanced flow of high salinity NAD waters, that resulted in high rates of deep water formation in the NE Atlantic marginal basins, as illustrated by other studies for the 9-7 ka BP interval (e.g., Duplessy et al., Boreas 30: 2-16, 2001). Formation of intermediate water, in the Labrador Sea, started at ca. 7 ka BP (Hillaire-Marcel et al., Nature 410: 1073-1077, 2001), and has increased since then, thus showing an opposite trend with the NE sector record. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO EVOLUTION AND ENDEMISM OF FRESHWATER DIATOMS IN EAST ANTARCTICA

AUTHORS_XXO SPAULDING, SARAH A. (1); McKnight, Diane M. (2)

AUTHOR_1_XXO (1) California Academy of Sciences; sspaulding@calacademy.org
AUTHOR_2_XXO (2) INSTAAR; diane.mcknight@colorado.edu

PARAGRAPH_1_XXO Although it is often accepted that freshwater diatoms are widely distributed, recent evidence points increasingly to the regional distribution of species (Kociolek & Spaulding 2000). In Antarctica, a number of diatom species are endemic to the east, and the lakes of East and West Antarctica share very few species in common (Prescott 1979, Jones 1999). Diatoms endemic to lakes of East Antarctica may be considered along two separate gradients: one gradient lies in terms of evolutionary position, and the other lies in terms of distribution. The range of evolutionary position extends from relatively primitive or relatively advanced within a given diatom lineage.  Similarly, historical distribution may range from existence as a relict of a warmer Antarctic continent to invasive species with a relatively recent history on the continent. We are examining the phylogenetic relationships of species endemic to East Antarctica in order to resolve the position of endemic taxa on each of these gradients. Evidence from records of Muelleria (Spaulding & Stoermer 1997, Spaulding et al. 1999) show that this genus has a long Antarctic history, and its distribution is more related to continental position than environmental conditions. While this appears to be the pattern for Muelleria, there may be alternate explanations for other taxa. We suggest that biogeographic distribution of individual species may lie on a spectrum ranging from historical contingency to ecological tolerance. Resolving the position of each taxon on this spectrum will aid in determining the evolutionary history of species and increase the utility of diatoms in making interpretations of paleoenvironments. 

REFERENCE_XXO Jones, V. 1999. The diversity, distribution and ecology of diatoms from Antarctic inland waters. Biodiversity and Conservation
REFERENCE_XXO Kociolek, J.P. & S.A. Spaulding. 1999. Freshwater diatom biogeography. Nova Hedwigia 71: 223-241.
REFERENCE_XXO Prescott, G.W. 1979. A contribution to a bibliography of Antarctic and Subantarctic algae. Bibliotheca Phycologica 45: 1-312.
REFERENCE_XXO Spaulding, S.A., J.P. Kociolek & D. Wong. 1999. A taxonomic and systematic revision of the genus Muelleria (Bacillariophyta). Phycologia 38: 314-341.
REFERENCE_XXO Spaulding, S.A. & E.F. Stoermer. 1997. Taxonomy and distribution of the genus Muelleria Frenguelli. Diatom Research 12: 95-113.

INSERT_PAGE_BREAK_HERE
TITLE_XXO HOLOCENE RECORDS OF PALEOSECULAR VARIATION FROM THE ARCTIC: ELLESMERE ISLAND AND THE NORTH ICELAND SHELF

AUTHORS_XXO STONER, JOSEPH  S. (1); Patridge, Whitney (2); Francus, Pierre (3); Andrews, John T. (4); Bradley, Raymond S. (5); Andrews, John  (6); Koc, Nalan   (7); Retelle, Mike (8)

AUTHOR_1_XXO (1) INSTAAR, University of Colorado; joseph.stoner@colorado.edu
AUTHOR_2_XXO (2) University of Massachusetts; patridge@geo.umass.edu
AUTHOR_3_XXO (3) University of Massachusetts; francus@geo.umass.edu
AUTHOR_4_XXO (4) INSTAAR, University of Co; andrewsj@spot.colorado.edu
AUTHOR_5_XXO (5) University of Massachusetts; rbradley@geo.umass.edu
AUTHOR_6_XXO (6) University of Pittsburgh; mabbott1@pitt.edu
AUTHOR_7_XXO (7) Norsk Polarinstitutt; Nalan.Koc@npolar.no
AUTHOR_8_XXO (8) Bates College; mretelle@bates.edu

PARAGRAPH_1_XXO Because of its proximity to the magnetic pole, the Arctic is an important location for understanding past geomagnetic behavior.  Unfortunately, few observations from high latitude locations exist and, therefore, our knowledge of Holocene geomagnetic field behavior is incomplete.  Towards resolving this issue, we present initial results of a u-channel paleomagnetic study of 2 cores from 2 lakes in Ellesmere Island, Nunavut in the Canadian high Arctic and one long piston core taken off the north coast of Iceland.  Sawtooth Lake, is an oligotrophic lake located at the southwestern part of Forsheim peninsula.  Core SS99-10-6B (Lat: 79º20'58.89"N, Long: 83º56.12.65W, water depth of 80.62 m; length 463 cm) is one of several vibracores and glew cores taken during the 1999 field season.  Murray Lake, also oligotrophic, is located on the eastern coast of Ellesmere Island, near the Archer fjord.  Core ML01-03-VC1 (Lat: 81°34.328 N. Long. 69°54.291 W, water depth 45.5 m; length 515 cm) was taken during the spring of 2001 and constitutes one of two vibracores and several short glew cores taken from the north basin.  Sawtooth Lake contains annual clastic laminations, providing a varve chronology that is estimated to extend for the last 2600 yrs with a sedimentation rate of approximately 180 cm /kyr.  Murray Lake is intermittently laminated and its chronology is unsure.  MD99-2269 (Lat: 66°13.93 N. Long. 23°15.93 W, water depth 106 m; length 2530 cm) was collected during the summer of 1999 as part of the international IMAGES-V (International Marine Past Global Change study) campaign aboard the Marion Dufresne II.  Chronology for this core is provided by 10 AMS 14C dates and several ash layers with known ages, suggesting that this record covers approximately last 12,000 yrs with an average sedimentation rate of approximately 200 cm/kyr. 
PARAGRAPH_XXO  The natural remanent magnetization (NRM) was studied by progressive alternating field (AF) demagnetization of u-channel samples, which indicate a strong, stable single component magnetization for all three cores. The inclination varies about a mean close to the expected inclination for each cores site latitude.  Comparisons of the inclination, declination, and relative paleointensity records between Sawtooth and Murray Lakes allow an optimized correlation to be made that takes into account the full magnetic vector.  If this can be substantiated, this suggest that an accurate representation of the full magnetic vector can be obtain from High Arctic Lakes and intern be used as a chronostratigraphic tool.  Additionally these data appear to be consistent with discrete sample paleomagnetic data from Cape Hurd Lake, Devon Island and therefore suggest that these sediments may be recording a regionally consistent geomagnetic pattern.  Patterns of secular variation (inclination and declination) from MD99-2269 are similar to those derived from previously published data from Icelandic lakes and are generally consistent with the patterns observed from Ellesmere and Devon Islands.  Features similar to those found in published records from North America and Europe are also observed. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO ABOVE AND BELOWGROUND PRODUCTION PATTERNS IN ALASKAN TUSSOCK TUNDRA: PLASTICITY IN RESPONSE TO CLIMATE CHANGE

AUTHORS_XXO SULLIVAN, PATRICK F. (1); Welker, Jeffrey M. (2); Fahnestock, Jace T. (3)

AUTHOR_1_XXO (1) Natural Resource Ecology Laboratory, Colorado State University; paddy@nrel.colostate.edu
AUTHOR_2_XXO (2) Natural Resource Ecology Laboratory, Colorado State University; jwelker@nrel.colostate.edu
AUTHOR_3_XXO (3) Natural Resource Ecology Laboratory, Colorado State University; jace@nrel.colostate.edu

PARAGRAPH_1_XXO Understanding system nutrient and water balance under current and future climate regimes requires a thorough knowledge of plant resource allocation.  With recent improvements in optic and electronic technology, minirhizotron camera systems have become a useful tool for measuring root production dynamics in some natural systems.  This study examined the patterns of shoot growth relative to root production and the influence of warming, fertilization and increased winter snow on differential resource allocation.  Shoot growth measures and minirhizotron images were taken on a mean interval of 7.7 days during the 2001 growing season, with an additional fall sampling date to capture late season root production. 
PARAGRAPH_XXO  
PARAGRAPH_XXO Results from our control plots suggest an inverse relationship between aboveground growth rate and belowground production rate in the moist tussock system.  During periods of peak aboveground growth rate, belowground production rate was at a relative minimum.  Conversely, during periods of peak belowground production rate, aboveground growth rate was at a relative minimum.  In contrast with control plots, warming and fertilization treatments produced periods of high concurrent above- and belowground production early in the growing season, but resumed the pattern of mutual exclusivity by mid-July.  Allocation patterns in plots treated with increased winter snow displayed a magnified case of mutual exclusivity in aboveground growth and belowground production.  Upon emergence from the snow, nearly all growth was concentrated aboveground.  With progression of the growing season, belowground production rate increased steadily, while aboveground growth rate decreased steadily, such that the aboveground minimum and the belowground maximum were coincidental in late August.  
PARAGRAPH_XXO These patterns, derived from treatment and control plots, suggest a trade-off in resource allocation, where environmental constraints necessitate partitioning of carbon and nutrient acquisition.  We hypothesize that, in addition to nutrient limitation, conditions specific to the respective microclimates of roots and shoots are important determinants of the observed patterns.  Patterns in aboveground growth may closely correspond with variables such as photosynthetically active radiation and ambient air temperature, while patterns in belowground production, in addition to the indirect influence of aboveground variables, may correspond closely with soil temperature, depth of thaw and microbial biomass.  Based on these differences, we hypothesize that the apparent mutual exclusivity in aboveground growth and belowground production is a consequence of the buffered soil environment, which delays the onset and extends the terminus of the growing season, and the balance between cumulative microbial metabolism and plant available nutrients.  These hypotheses will be tested in a path analysis framework. 

INSERT_PAGE_BREAK_HERE
TITLE_XXO COLD AND DRY, YES, BUT ABOVE ALL VOLATILE: THE INHOSPITALITY OF  PLEISTOCENE CLIMATES TO TRANSITIONS TO AGRICULTURE

AUTHORS_XXO VASEY, DANIEL E.

AUTHOR_1_XXO Divine Word College; dvasey@dwci.edu

PARAGRAPH_1_XXO Pleistocene climatic instability played as large a role in preventing transitions to agriculture as did the widespread cold and aridity.  This proposal is based in part on the demography of historic Arctic foragers and other peoples living under highly unstable exogenous conditions.  Such
PARAGRAPH_XXO conditions favor systems of small, mobile local populations that gain adaptability to short-term resource variation but tend to maintain wide distances between them and to incur high risks of extinction.  Such systems were ill suited to transitions to agriculture.
PARAGRAPH_XXO A high-resolution temperature proxy, oxygen isotope ratios in the GISP2 (Greenland) ice cores, shows swings during Pleistocene stadials that are about 2 1/2 times as large as those during the Holocene.  Figure 1 charts 20-year averages from 16490-4000 BP (after Meese et al 994; Stuiver et al 1997; Stuiver, Grootes, and Braziunas 1995; Steig, Grootes, and Stuiver 1994).  Figures 2 and 3 show observations during periods in the Younger Dryas and early Holocene, respectively (after Grootes, Stuiver 1997; Grootes et al 1993; Meese et al 1994; Stuiver, Grootes, and Braziunas 1995; Steig, Grootes, and Stuiver 1994).  Temperatures decrease towards the bottom of each graph.  The data were obtained from the World Data Center for Paleoclimatology.
PARAGRAPH_XXO Agriculture arose independently, involving separate sets of domesticated plants and animals, in at least eight places, probably eleven, and possibly more.  All domesticates whose identification is generally accepted and unambiguous date from the Holocene, though in one place, the Levant, domestication and intensified management of plants probably began during the Younger Dryas.
PARAGRAPH_XXO The absence or near absence of agriculture during the Pleistocene begs explanation.  A partial one lies in the widespread cold and aridity.  Holocene climates in which agriculture emerged ranged from tropical to middle temperate and from semiarid to humid.  Excluding other climates, as well as the Americas, whose occupation is uncertain before ca. 15,000 BP, the area of favorable biomes during stadials was about a third of its extent at the Holocene Optimum, when the Americas are included.  Nonetheless, all the plants and animals that were later domesticated survived somewhere in the Pleistocene.  Anatomically modern humans occupied the habitable parts of Africa, Asia, Europe, and Australia-New Guinea before 35,000 BP, warm parts well before that.  Opportunities for human exploitation of the plants and animals that were later
PARAGRAPH_XXO domesticated thus extended over a very long period before the Holocene, compensating the reduced favorable area.  More is needed in the way of explanation.
PARAGRAPH_XXO This paper reverses the logic of previous climatic explanations of transitions to agriculture.  In them changes in temperature or precipitation stressed populations of foragers, forcing change, or created conditions favorable for unintentional domestication.  Holocene climates have been particularly stable.  If climatic change alone led to agriculture, it should have happened many
PARAGRAPH_XXO times during the Pleistocene.  Holocene domesticates had survived Pleistocene climatic shocks, but the food available to humans, whether from these same plants and animals or others, possibly varied greatly under Pleistocene conditions.  This paper relates resource variation to the proposed population system.

REFERENCE_XXO Grootes, P.M., and M. Stuiver. 1997. Oxygen 18/16 variability in Greenland snow and ice with 10^3 to 10^5-year time resolution. Journal of Geophysical Research 102:26455-26470. 
REFERENCE_XXO Grootes, P.M., M. Stuiver, J.W.C. White, S.J. Johnsen, and J. Jouzel.1993. Comparison of oxygen isotope records from the GISP2 and GRIP Greenland ice cores. Nature 366:552-554. 
REFERENCE_XXO Meese, D.A., R.B. Alley, R.J. Fiacco, M.S. Germani, A.J. Gow, P.M. Grootes, M. Illing, P.A. Mayewski, M.C. Morrison, M. Ram, K.C. Taylor, Q.Yang, and G.A. Zielinski. 1994. Preliminary depth-age scale of the GISP2 ice core. Special CRREL Report 94-1, US.
REFERENCE_XXO Stuiver, M., T.F. Braziunas, P.M. Grootes, and G.A. Zielinski. 1997. Is there evidence for solar forcing of climate in the GISP2 oxygen isotope record?  Quaternary Research 48:259-266.
REFERENCE_XXO Stuiver, M., P.M. Grootes, and T.F. Braziunas. 1995. The GISP2 18O climate record of the past 16,500 years and the role of the sun, ocean and volcanoes. Quaternary Research 44:341-354. 
REFERENCE_XXO Steig, E.J., P.M. Grootes, and M. Stuiver. 1994. Seasonal precipitation timing and ice core records. Science 266:1885-1886. 

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/13-1.GIF

CAPTION_XXO Fig 1.  Bidecadal Oxygen Isotope Ratio Averages, 16490-4000 BP, GISP2 Ice Core.<br><br>

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/13-2.gif

CAPTION_XXO Fig 2.  Oxygen Isotope Ratios, 11600-11900, GISP2 Ice Core.<br><br>

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/13-3.gif

CAPTION_XXO Fig 3.  Oxygen Isotope Ratios, 7300-7600, GISP2 Ice Core.<br><br>

INSERT_PAGE_BREAK_HERE
TITLE_XXO SEDIMENTOLOGY AND MINERALOGY OF ARCTIC OCEAN SEDIMENTS - WHAT CAN WE LEARN FOR PALEOCEANOGRAPHY?

AUTHORS_XXO VOGT, CHRISTOPH (1); Knies, Jochen (2); Matthiessen, Jens (3); M…ller, Claudia (4); Wahsner, Monika (5); Stein, Ruediger (6); Fischer, Reinhard X. (7)

AUTHOR_1_XXO (1) Central Laboratory for Crystallography and Applied Material Science (CECAM), Geowissenschaften, Universitæt Br; cvogt@uni-bremen.de
AUTHOR_2_XXO (2) Geological Survey of Norway, Leiv Eiriksson vei 39, N-7491 Trondheim, Norway
AUTHOR_3_XXO (3) Alfred-Wegener-Institut f…r Polar- und Meeresforschung, Bremerhaven, Columbusstr. 27515 Bremerhaven, Germany
AUTHOR_4_XXO (4) Alfred-Wegener-Institut f…r Polar- und Meeresforschung, Bremerhaven, Columbusstr. 27515 Bremerhaven, Germany
AUTHOR_5_XXO (5) Alfred-Wegener-Institut f…r Polar- und Meeresforschung, Bremerhaven, Columbusstr. 27515 Bremerhaven, Germany
AUTHOR_6_XXO (6) Alfred-Wegener-Institut f…r Polar- und Meeresforschung, Bremerhaven, Columbusstr. 27515 Bremerhaven, Germany
AUTHOR_7_XXO (7) Central Laboratory for Crystallography and Applied Material Science (CECAM), Geowissenschaften, Universitæt Br

PARAGRAPH_1_XXO The highly sensitive sea-ice cover of the Arctic Ocean, the exchange of surface and deep water masses with the global ocean and the coupling with the atmosphere interact directly with global climatic changes. The terrigenous content of Arctic Ocean sediments is an outstanding archive to investigate changes in the paleoenvironment. As conditions are harsh for life, and remnants and fossils are sparse, it is only the lithology and minerology of Arctic Ocean sediments which can always be used for paleoceanographic reconstructions. Despite many sedimentological-lithological investigations, detailed mineralogical investigations are comparatively sparse, in particular in the central Arctic Ocean. But the potential for the investigation of sediment sources, transport pathways, and sedimentation environments is high (e.g. Darby et al., 1989, Nürnberg et al., 1994, Vogt et al., 2001).
PARAGRAPH_XXO The impact of sea-ice cover on the sedimentation is of particular interest as its large extent compared to its small thickness results in an extreme sensitivity to climatic change. Predominantly fine grained material is entrained in the shallow shelf regions (< 30 m water depth) and in particular in the polynyas where most sea ice is formed. Newly produced sea-ice transports smectite-rich sediments from the Laptev and Kara Seas to the Fram Strait through the Southern Eurasian Basin of the Arctic Ocean (Pfirman et al., 1997). Northwest of Svalbard relatively warm Atlantic Water of the northward flowing Westspitsbergen Current submerge at the Polar Front beneath the cold sea-ice covered Polar Water. The position of the Polar Front and the sea-ice edge depends on the strength of the WSC and the outflow of the Polar Water. Fine grained sediments, just released from melting sea-ice may be deposited on the sea-floor very close to the actual position of the marginal ice zone due biologically accelerated sedimentation. As sea-ice contains high amounts of smectite, bottom sediments derived from sea-ice should contain increased smectite contents. This is one example how the mineralogical composition of sediments may help to reconstruct paleoenvironmental conditions such as drift paths of sea-ice and source areas of sediments.
PARAGRAPH_XXO Additionally, the mineral content of different grain size classes can give even more detailed information on the origin of terrigenous sediments. As an example we show here the sediment record of Polarstern Core PS2757 from the southernmost tip of the Lomonosov Ridge, close to the Laptev and East Siberian shelf seas. The stratigraphic framework is based on the correlation to adjacent sediments cores which have a well established chronostratigraphy (Stein et al., 2001). Here we concentrate on mineralogical indicators which reflect sediment input from the Putorana Flood Basalts (PFB). The erosional products are transported by the Khatanga River to the western Laptev Sea. These sediments may be then redistributed northeastward by currents and sea-ice to the core position on the southernmost tip of the Lomonosov Ridge. The flood basalts can be traced in the sediments by different marker minerals such as the smectite group in clay fraction investigation and the (clino) pyroxenes in the heavy mineral fraction. In the bulk fraction analysis the PFBs are represented by the Expendable Minerals group (Exp. Min.), which is the sum of the montmorillonite, smectite and expandable mixed-layer clay contents in the bulk sediment. The comparison of the Exp.Min. to the the clay fraction smectite group curve shows some similarities but many dissimilarities. While the clay fraction data illucidates the dominance of the PFB derived material in the clay fraction the Exp.Min. accumulation rate is several times strongly related to the clay fraction accumulation rate. Most strikingly this can be seen between 26,000 and 12,000 calendar years. While the clay mineral content data does not show an increase in PFB material input the Exp.Min. accumulation rate together with the pyroxene in the bulk material and in particular the clinopyroxene contents in the heavy mineral analysis are increased.
PARAGRAPH_XXO At this point one has to realize that all different mineral fractions have to be regarded for the paleoceanographic reconstruction. This particular enigma in the mineral signal can be explained by the paleosituation of the Laptev Sea during the last glaciation. The shallow shelf was subaerially exposed and the rivers cut their beds to the shelf edge. Current transport from the western to the eastern Laptev Sea shelf was not possible, and boundary currents along the continental slope might not have been as active as today. Therefore, the clay mineralogy of the sediment core was probably strongly influenced by sediment input from the adjacent paleo-Lena. On the other hand the clay fraction became dominant and the clay accumulation rate doubled around 26,000 years before today. The heavy minerals have been assumed to be transported mainly by sea-ice (Behrends, 1999). Today, sea-ice contains mainly (very) fine fraction sediment due to the uptake as frazil ice in late autumn during freeze up. If the same process had been active in the vicinity of the former Khathanga mouth at the western Laptev Sea shelf, a lot of sediment with PFB signature could have been transported eastward to the sediment core position. This is only possible if the Arctic Ocean circulation is the same as today. Several sediment cores on the northern Barents Sea continental slope do show that Atlantic water influx to the Arctic Ocean was absent in particular during the last glaciation. 
PARAGRAPH_XXO In our presentation we will discuss more examples, how the mineral content of sediments could be used for Arctic Ocean paleoceanographic reconstructions. 

REFERENCE_XXO Behrends, M., 1999, Reconstruction of sea-ice drift and terrigenous sediment supply in the Late Quaternary: Heavy-mineral associations in sediments of the Laptev-Sea continental margin and the central Arctic Ocean: Bremerhaven, Alfred Wegener Institute for Polar and Marine Research, Reports on Polar Research, v. 310, 167 p.
REFERENCE_XXO Biscaye, P.E., 1965. Mineralogy and sedimentation of recent deep-sea clays in the Atlantic Ocean and adjacent seas and oceans. Geological Society of America Bulletin, 76: p. 803-832.
REFERENCE_XXO Darby, D.A., Naidu, A.S., Mowatt, T.C. and Jones, G., 1989. Sediment composition and sedimentary processes in the Arctic Ocean. In: Y. Herman (Editor), The Arctic Seas - Climatology, Oceanography, Geology, and Biology. van Nostrand Reinhold, New York, pp. 657-720.
REFERENCE_XXO M…ller, C., 1999, Reconstruction of the paleoenvironmental conditions at the Laptev Sea continental margin during the last two glacial/interglacial cycles based on sedimentological and mineralogical investigations: Bremerhaven, Alfred Wegener Institute for Polar and Marine Research, Reports on Polar Research, v. 328, 146 p.
REFERENCE_XXO N…rnberg, D. et al., 1994. Sediments in Arctic sea ice: Implications for entrainment, transport and release. Marine Geology. v.119, p. 185-214.
REFERENCE_XXO Pfirman, S.L., Colony, R., N…rnberg, D., Eicken, H. and Rigor, I., 1997. Reconstructing the origin and trajectory of drifting Arctic sea ice. Journal of Geophysical Research, v. 102(C6): p. 12,575-12,586.
REFERENCE_XXO Stein, R., Boucsein, B., Fahl, K., Garcia de Oteyza, T., Knies, J., and Niessen, F., 2001, Accumulation of particulate organic carbon at the Eurasian continental margin during the late Quaternary times: Controlling mechanism and paleoenvironmental signifcance: Global and Planetary Change, v. 31 (1-4), p. 87-102.
REFERENCE_XXO Vogt, C., Knies, J., Spielhagen, R.F. and Stein, R., 2001. Detailed mineralogical evidence for two nearly identical glacial/deglacial cycles and Atlantic water advection to the Arctic Ocean during the last 90,000 years. Global and Planetary Change, 31(1-4): p. 23-44

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/3-1.jpg

CAPTION_XXO Fig 1.  Fig. 1 Mineralogical Data and Sediment Accumulation rates of grain sizes and minerals of PS2757-8 from the southernmost tip of Lomonosov Ridge, Arctic Ocean (81î09¸6N, 140î12.0¸E; 1230 m water depth). From left to right: Bulk sediment accumulation rate (ACC), ACC of the Expandable Minerals Group in the bulk sediment, ACC of the clay fraction (<2 µm), content of the clay mineral group smectite (calculated according to Biscaye, 1965) in the clay fraction, integrated area of the most pyroxene peaks in the X-ray diffractogram of the bulk material as direct measure of pyroxene content in the bulk sample, ACC of the sand fraction (63-2000µm), content of the pyroxenes from a heavy mineral  fraction investigation (based on counting of grains in a slide through light microscopy of the seperated heavy mineral fraction; Behrends, 1999). 

INSERT_PAGE_BREAK_HERE
TITLE_XXO HUMAN AND ECOSYSTEM DYNAMICS IN THE ARCTIC: THE IMANDRA WATERSHED PROJECT (KOLA, RUSSIA)

AUTHORS_XXO VOINOV, ALEXEY A. (1); Kirk, Elizabeth (2); Moiseenko, Tatyana I. (3); Selin, Vladimir V. (4); Makarova, Zoya V. (5); Sandimirov, Sergei (6)

AUTHOR_1_XXO (1) IEE; voinov@cbl.umces.edu
AUTHOR_2_XXO (2) AAAS; ekirk@aaas.org
AUTHOR_3_XXO (3) IWP RAN; tatyana@aqua.laser.ru
AUTHOR_4_XXO (4) IEP KSC; selin@iep.kolasc.net.ru
AUTHOR_5_XXO (5) INEP KSC; zoya@inep.ksc.ru
AUTHOR_6_XXO (6) INEP KSC; sand@inep.kolasc.net.ru

PARAGRAPH_1_XXO A US-Russian research effort has been started in the Kola Peninsula to increase understanding of the interaction of human dynamics and ecosystem functions and explore development strategies to enhance ecosystem health, ecological sustainability and economic diversity. The project focuses on the Imandra Lake watershed. 
PARAGRAPH_XXO The Imandra Lake watershed is located in one of the most developed regions in the Arctic - the Kola Peninsula of Russia (Fig.1).  There are approximately 300 thousand people living on the watershed, which makes it one of the most densely populated areas in the Arctic.  The unusually high population of this area can be attributed to two factors.  One is the relatively warm climate influenced by the Gulf Stream.  The second factor is the history of forced development of the territory in the 1930s-50s, when thousands of Gulag prisoners were brought in to provide labor for the extractive industry.  Most of the people who live there are still involved in the large-scale extraction and processing of minerals and in the infrastructures needed to support it.  
PARAGRAPH_XXO The human impact in the region has been quite massive. On vast territories we find radioactive and chemical contamination by human and industrial wastes, deforestation caused by acidification, and other degradation from human activity (NEFCO, 1996).  Industrialization of the area is associated with huge tailings, landfills, increased risks of nuclear and chemical accidents, and high loads of contaminants harmful to humans as well as to many other organisms. 
PARAGRAPH_XXO The Interactive Assessment Approach
PARAGRAPH_XXO For the Imandra Lake watershed we are developing site-specific databases and models that overlay and integrate the following types of data:
PARAGRAPH_XXO 1.  Biogeochemical cycles of the watersheds (hydrology);
PARAGRAPH_XXO 2.  Population consumption patterns including land use, mineral extraction, water use, food production and consumption (by different ethnic groups and sectors of the society) with some description of indigenous knowledge of populations living in the region before large-scale development began (demographics, ethnology, sociology);
PARAGRAPH_XXO 3.  Contaminant transport information and water quality;
PARAGRAPH_XXO 4.  Global change in the region and expected impacts;
PARAGRAPH_XXO 5.  Economic assessment of ecosystem goods and services and costs of pollution control;
PARAGRAPH_XXO 6.  Ecosystem health indicators (fish stocks, water quality, erosion control, human health, etc.);
PARAGRAPH_XXO 7.  Scenarios developed by regional stakeholders that look specifically at their needs.
PARAGRAPH_XXO The emphasis of the interviews and workshops is to involve the stakeholders in the process from the very beginning and develop through their discussions models of economic and social dynamics.  The stakeholder workshops and the data collected feed into a modeling process that is based on the Landscape Modeling Approach (LMA) developed at the University of Maryland?s Institute for Ecological Economics (IEE) and currently adapted for Arctic environments and transitional economies. The IEE has been developing the capability to model watersheds as spatially explicit, integrated, ecological economic systems (Fig.2).  The LMA has been implemented in a number of case studies, including the Florida Everglades (http://iee.umces.edu/Glades/ELM.html), the Patuxent watershed (see: http://iee.umces.edu/PLM) and its subwatersheds, Hunting Creek in particular (see http://iee.umces.edu/PLM/HUNT) (Voinov, et al., 1999).  
PARAGRAPH_XXO We assume a broad definition of a model, in that in most of our modeling studies we are always dealing with qualitative and quantitative models simultaneously.  These include:
PARAGRAPH_XXO - Data models that are based on measurements and experiments;
PARAGRAPH_XXO - Qualitative, conceptual frameworks of systems and processes involved;
PARAGRAPH_XXO - Quantitative numeric models that are used to formalize our qualitative models;
PARAGRAPH_XXO - Mathematical methods and models used to analyze the numeric models and interpret the results;
PARAGRAPH_XXO - Decision-making models that transform our values and knowledge into actions.
PARAGRAPH_XXO Our goal then is to integrate these models within a transparent and interactive framework that allows participation of stakeholders in all the stages of the process, that integrates their individual models into the overall structure, and organizes the stakeholders? community helping them communicate understanding, values, and concerns. Most important is not a unique model implementation that is developed, but rather an ongoing process of integrated assessment.  
PARAGRAPH_XXO Development Alternatives
PARAGRAPH_XXO Over the last hundred years, human activity, begun as fishing, reindeer herding, fur trade and gold mining, and evolving in the 1930s to mineral extraction and urbanization, has produced land use changes that have altered Arctic landscapes in ways that scientists are just beginning to understand. Because of recent economic collapse in the area, mineral extraction activities have decreased substantially, thereby decreasing the major point sources of pollution in the Imandra Lake watershed. Over 160,000 people have left the Kola, leaving a population of approximately one million inhabitants. Moiseenko (2000) observes that this slowdown has led to much improved water quality and watershed recovery that is faster than assumed in the Arctic. Some recent field studies confirm these estimates.  For example in Fig. 3 we compare the distribution of nickel concentrations in the surface waters of Lake Imandra, averaged over 9 lake compartments.  Ni is the major pollutant discharged by the Severo-Nickel enterprise in Monchegorsk. It is yet to be estimated how fast this recovery is propagating throughout the lake trophic chains, however it is already clear that the economic meltdown was beneficial to the ecological components of the system.  At the same time the reaction of the socio-economic components was quite adverse, they hardly benefited from the ecological recovery.  
PARAGRAPH_XXO The integration of the economy into the world market has entirely changed the demand patterns for the major products delivered by the region.  Whereas under planned economy most of the production was secured for domestic consumption, now the regional economy became much dependent on world market situation. The integration of the Kola North into the free-market system will be a painful process.  It is not yet clear whether the industries will be able to keep the competitive edge, bearing in mind their remote location, high transportation prices, cold climate, that requires huge spending for heating and lighting during the Polar night.  There are also examples when development is not so much dependent on industrial growth.  For example, a switch to a free-market, capitalist system may lead residents to assume more traditional economic structures. Analysis is required to suggest whether there are multiple strategies that local residents can utilize to achieve economic self-sufficiency or if there is a single adaptive strategy that stakeholders can utilize to transition to new economic forms. 
PARAGRAPH_XXO A series of problems in the Imandra watershed are associated with demographic and social aspects.  Aging of population is now a typical trend for the North. The number of retired people here at the beginning of 1992 was 167.7 per 1000, in 1996 - 208.5. At the same time the financial resources directed for social security have diminished and in 1996 they were 64% of 1990 level, and the estimate for 1997 is 62% (Luzin, et al, 1999). In terms of social security the region has never been, and is even less self-sufficient now. At the same time the collapse of many social security programs has dramatically decreased the ability of pensioners to leave the area. The migratory patterns are characterized by a sharp decrease in newcomers. 
PARAGRAPH_XXO The whole issue of sustainability is a hard one for the area. It is not clear if sustainability can really be the issue for this region at all. Today it would probably make more sense to be concerned with design of adaptive management strategies, than should result in sustainable systems in the future. 
PARAGRAPH_XXO Using existing data analyses, maps and other sources we can model the economic and ecological development of the system up till today.  Then, three ?alternative? frameworks will be examined that take into account past, present, and future notions of development:
PARAGRAPH_XXO 1.  Scenarios, which go back to redeveloping the same kind of resource extraction and processing industries that developed over the past 60 years or so ? the ?business as usual? scenarios.
PARAGRAPH_XXO 2. Scenarios, which look at more sustainable economic development ? the ?best management practices? (BMP) scenarios.
PARAGRAPH_XXO 3. Scenarios, which include some of the nomadic economic sustainability concepts found in early Saami, Nenets, Pomor, and other indigenous groups (Krasovskaya, 1998) ? the ?eco-alternative? scenarios.
PARAGRAPH_XXO As a result we are developing conceptual frameworks and interdisciplinary models linking human dynamics with Arctic ecosystem functions. The research, databases, and integrated models can then be used for educational and policy-making purposes in addition to its integration into Arctic System Science research.  Moreover, we intend to set up a framework for the process of dialogue among various stakeholders, which will contribute to consensus building on development scenarios and measurable steps towards ecological sustainability in the region.
PARAGRAPH_XXO At this time there are certainly more open questions than answers available.  We are assembling the data sets, formulating the major model hypotheses, and starting the stakeholder workshop process to elicit feedback and ensure future involvement of the stakeholders in the research process and its results.  The project web site is http://xserver.aaas.org/international/eca/kola/, there is also a mirror site in the Kola and we intend to make most of the results and data sets available thorugh these web sites.

REFERENCE_XXO Krasovskaya, T.M., 1998. Cultural Landscape of Far-Northern Regions of Russia as a Basis for Sustainable Development. In: Cultural Landscape: Problems of Theory and Research Methodology. (in Russian), Smolensk State University, Smolensk, p.45-71.
REFERENCE_XXO Luzin, G.P., Selin, V.S., et al., 1999. Stability and Economic Security in Regions: Trends, Criteria, Regulation Mechanism. Apatity, Kola Science Center, 174 p. (In Russian).
REFERENCE_XXO Moiseenko, T., 2000. The Imandra Lake Watershed: The contradictions of ecological and economic interests, Presentation at the 2000 AAAS Annual Meeting, Washington, DC.
REFERENCE_XXO NEFCO (Nordic Environmental Finance Corporation), 1995. Proposals for Environmentally Sound investment projects in the Russian Part of the Barents Region, Vols. I and II. Oslo: AMAP Expert Group. December.
REFERENCE_XXO Voinov, A., R. Costanza, L. Wainger, R. Boumans,  F. Villa, T. Maxwell and H. Voinov, 1999. Patuxent landscape model: integrated ecological economic modeling of a watershed. Journal of Ecosystem Modelling and Software: 14, 473-491.

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/76-1.gif

CAPTION_XXO Fig 1.  Geolocation of the Imandra Lake watershed

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/76-2.gif

CAPTION_XXO Fig 2.  Major modules involved in the Landscape Modeling Approach

INSERT_FIGURE /INSTAAR/ArcticWS/data/figures/76-3.

CAPTION_XXO Fig 3.  Comparison of Ni concentration is Lake Imandra waters in 1992 and 2001. Based on annual monitoring of water quality in the surface and bottom layers at 28 sampling stations on the Lake

INSERT_PAGE_BREAK_HERE
TITLE_XXO HYPSOMETRIC ANALYSIS OF GLACIER TERMINUS FLUCTUATIONS: PRELIMINARY RESULTS FROM BYLOT ISLAND, NUNAVUT, CANADA

AUTHORS_XXO WALTER, FREDERIC SA. (1); Williams, Jeffrey LM. (2); Sjogren, Darren B. (3); Moorman, Brian J. (4)

AUTHOR_1_XXO (1) University of Calgary; fswalter@ucalgary.ca
AUTHOR_2_XXO (2) University of Calgary; jlwillia@ucalgary.ca
AUTHOR_3_XXO (3) University of Calgary; sjogren@ucalgary.ca
AUTHOR_4_XXO (4) University of Calgary; moorman@ucalgary.ca

PARAGRAPH_1_XXO While substantial, the impacts of a rapidly changing climate on fragile northern environments are poorly understood.  In particular, the linkages between climate, glacier response and geomorphic activity in areas of glaciated / non-glaciated transition are exceptionally complex.  It is often assumed that a change in glacier terminus position represents a response to a change in climate.  Although certainly the case in the long term, it is unclear how the dynamics of glaciers cause lagged responses which, in turn, influence the pattern of retreat in the short term.  This research project focuses on the fluctuation of glacier terminus positions on Bylot Island, Nunavut, Canada.
PARAGRAPH_XXO Recent investigations on Bylot Island, located off the northeastern shore of Baffin Island in the Eastern Canadian Arctic, determined that--of the 18 glaciers in the study area--10 demonstrated noticeable signs of retreat (i.e. a negative mass balance).  Implementation of remote sensing techniques identified that over a 46-year period a single glacier (B28) retreated 1.8 km, while an adjacent glacier (B26) experienced no appreciable retreat (Moorman and Michel 2000).  This research project attempts to explain the disparate advance and retreat patterns identified on Bylot Island despite the juxtaposition of similar-sized glaciers in the study area.
PARAGRAPH_XXO The disparate response of glaciers on Bylot Island to changes in climate confuses any attempt to generalize how the glaciers should, or have, responded to climatic events.  While some of the variation may be explained by differences in local climate surrounding individual glaciers, Furbish and Andrews (1984), referring to glaciers in general, stated that much of the variation could be attributed to the many morphological and glaciological features that distinguish individual glaciers.  These include--but are not limited to--differences in glacier size, steepness, elevation, mass turnover and areal distribution of accumulation and ablation zones.  This research examines one way in which valley topography is linked to long-term glacier response through the distribution of a glacier's surface area over elevation (i.e. the glacier's hypsometry) and the distribution of mass balance over elevation.
PARAGRAPH_XXO First introduced by Langbein et al. in 1947, the hypsometric curve describes the distribution of area with elevation.  Strahler (1952) extended the idea to include the percentage hypsometric curve and the hypsometric integral.  Although historically used in geomorphic analysis of form and process, recent studies by Furbish and Andrews (1984) and Rivera and Casassa (1999) demonstrated the utility of hypsometric analysis in glaciological applications.  A synoptic analysis of glacier hypsometry for Bylot Island combined with an approximation of the Equilibrium Line Altitude (ELA) is being used to determine the sensitivity of selected glaciers to changes in the ELA (and thus to changes in climate).  Preliminary results from glaciers B26 and B28 will be presented.

REFERENCE_XXO Furbish, D.J. and Andrews, J.T.  1984.  The use of hypsometry to indicate long-term stability and response of valley glaciers to changes in mass transfer.  Journal of Glaciology, 30: 199-211.
REFERENCE_XXO Langbein, W.B., and Others.  1947.  Topographic characteristics of drainage basins.  United States Geological Survey, Water-Supply Paper, 968-C: 125-158.
REFERENCE_XXO Moorman, B.J. and Michel, F.A.  2000.  The burial of ice in the proglacial environment on Bylot Island, Arctic Canada.  Permafrost and Periglacial Processes, 11: 161-175.
REFERENCE_XXO Rivera, A. and Casassa, G.  1999.  Volume changes on Pio XI glacier, Patagonia: 1975-1995.  Global and Planetary Change, 22: 233-244.
REFERENCE_XXO Strahler, A.N.  1952.  Hypsometric (area-altitude) analysis of erosional topography.  Bulletin of the Geological Society of America, 63: 1117-1142.

INSERT_PAGE_BREAK_HERE
TITLE_XXO FLOW DYNAMICS OF A POLYTHERMAL GLACIER, STAGNATION GLACIER, BYLOT ISLAND, NUNAVUT, CANADA

AUTHORS_XXO WILLIAMS, JEFFREY LM. (1); Walter, Frederic SA. (2); Moorman, Brian J. (3)

AUTHOR_1_XXO (1) University of Calgary; jlwillia@ucalgary.ca
AUTHOR_2_XXO (2) University of Calgary; fswalter@ucalgary.ca
AUTHOR_3_XXO (3) University of Calgary; moorman@ucalgary.ca

PARAGRAPH_1_XXO 
PARAGRAPH_XXO From July 12 - July 21, 2001, a detailed survey was conducted on a section of the ablation area on Glacier B28, informally named Stagnation Glacier on Bylot Island, Nunavut, Canada.  The objective of the study was to quantify surface movement of an Arctic polythermal glacier.  Observations included measurements of surface movement in both vertical and horizontal directions.  The study was based on the assumption that meltwater, trapped within the glacier, would cause surface uplift, as had been previously observed on the glacier.  
PARAGRAPH_XXO  
PARAGRAPH_XXO Polythermal glaciers are dominated by a strong vertical temperature gradient in the ablation zone, while near the centre line, a thick covering of cold ice surrounds temperate ice that extends to the glacier bed.  Glacier movement in polythermal glaciers tends to increase during the summer over the entire ablation area, and may persist after the end of the melt season.  Researchers suggest that high water pressures and sliding above the lowest points of surface-water input may initiate the trapping of meltwater by the marginal zone of thin ice that is frozen to the bed, thus forcing meltwater up-glacier. 
PARAGRAPH_XXO Researchers observed turbid englacial water exiting the eastern and western margins of White Glacier, but not from the glacier snout, suggesting that a barrier of cold ice was preventing the drainage of meltwater to the snout (Skidmore 1995).  If, however, the basal hydraulic gradient is down glacier, meltwater will flow towards the snout and unable to penetrate the cold ice barrier, begins to pool.  If the meltwater input is significantly larger than the meltwater output, then water storage will occur until a critical point is reached and bed separation occurs. 
PARAGRAPH_XXO Glacier motion, on a daily to weekly temporal scale is characterized by; (a) correlation between surface water inputs and glacier motion, (b) time lag between surface water inputs and glacier motion, and (c) varying medium-term velocity increases with distance up glacier (Willis 1995).   Studies suggest that daily - weekly variations in glacier surface velocity are positively correlated with meltwater inputs derived from surface melt or rainfall (Willis 1995).  Daily - weekly increases in glacier surface uplift have currently only been reported for the Unteraargletscher Glacier in Switzerland.  Peak daily - weekly horizontal velocities were associated by three uplift events which resulted in the surface rising 0.51 m, 0.49 m and 0.53 m above the normal flow curve (Iken et al. 1983).
PARAGRAPH_XXO Previous radar studies have suggested that Stagnation Glacier is dominated by a transition of cold ice around the margins of the glacier and a core at the pressure melting point (Moorman and Michel 2000). Based on this assertion it is suggested that Stagnation Glacier is a polythermal glacier, thus resulting in the glacier being dominated by marginal streams and not by glacial streams exiting the terminus.
PARAGRAPH_XXO A detailed array of markers were surveyed using theodolite total station measurements of surface movement to observe horizontal and vertical displacement of a section of Stagnation Glacier.  Weather data was collected from a weather station located within the adjacent valley and discharge, conductivity and pH of the proglacial stream were monitored for the extent of the field season.  While preliminary results fail to reveal vertical uplift of the glacier surface, a surface lowering of ca. 1.70 mm/h, potentially caused by ablation, was observed.  Horizontal measurements revealed surface velocities of ca. 4-5 mm/h with peak velocities not corresponding to peaks in discharge.  Dye-tracing tests revealed that the drainage system evacuating Stagnation Glacier was dominated by rapid through flow which does not permit water storage to occur.  Future research will determine overall flow patterns of the glacier ice on the surface and internally and conclude whether ablation is the principal factor affecting surface lowering.       

REFERENCE_XXO Iken, A., Rothlisberger, H., Flotron, A. and Haeberli, W., 1983, The uplift of Unteraargletscher at the beginning of the melt season - A consequence of water storage at the bed?: Journal of Glaciology, vol. 29, p. 28-47.
REFERENCE_XXO Moorman, B.J. and Michel, F.A., 2000, Glacial hydrological system characterization using ground-penetrating radar: Hydrological Processes, v.14, p. 2645-2667.
REFERENCE_XXO Skidmore, M. L., 1995, The hydrology and hydrochemistry of a high Arctic glacier: Unpublished Master of Science Thesis, Unviersity of Alberta.
REFERENCE_XXO Willis, I. C., 1995, Intra-annual variations in glacier motion: a review: Progress in Physical Geography, v. 19, p. 61-106.

INSERT_PAGE_BREAK_HERE
TITLE_XXO MODERN MONGOLIA AND THE ANCIENT ARCTIC: A RESEARCH INITIATIVE

AUTHORS_XXO YOUNG, STEVEN B.

AUTHOR_1_XXO The Center for Northern Studies; cnsnorth@together.net

PARAGRAPH_1_XXO The Hovsgal region on Northern Mongolia lies at a Latitude of 48 to 50 degrees, yet its annual temperature regime is comparable to that of Nome or Kotzebue, Alaska. This is partly due to elevation, as the valley floors are at about 1500 meters, but the overall climate is much colder than that of areas of comparable elevation and latitude in,for example, western Canada. The precipitation regime in Mongolia is radically different in timing, if not in overall amount, from that of any modern Arctic area. Most of the Mongolian precipitation falls as rain during the summer months, and there is typically no significant snow cover throughout the intensely cold winters.
PARAGRAPH_XXO Although northern Mongolia is underlain by continuous permafrost, the aspect of the vegetation is radically different than that of Arctic areas. Moist, north-facing hillsides are heavily forested, and the drier and more exposed situations support steppe. This steppe can withstand heavy grazing by large quantities of animals, including sheep, goats, cattle, yaks, horses, and camels. Nonetheless, many of the steppe plant species, particularly at higher elevations and in enclosed valleys, are similar or identical to those of the present Alaskan forest tundra and tundra. It seems likely that the large numbers of grazing animals can exist because a) the combination of well-drained soils and heavy rainfall during the summer make for high productivity of fodder, and b) this fodder is available throughout the winter because of low snowfall. This raises the possibility that northern Mongolia might be at least a partial analogue for ancient Beringia. There, a cold, highly continental climate seemed to support a vegetation that could, in turn, allow large numbers of large herbivores to survive and prosper.
PARAGRAPH_XXO Another interesting feature of the Mongolian vegetation is that, at higher elevations, it takes on the aspect of a wet sedge meadow, again with many typically arctic species. This appears to be much less productive, in terms of its ability to support large herbivores, although this may be more a function of winter snow cover than actual productivity. We suggest that the vegetation of this moist, cloudy upland might be comparable to the apparently birch-dominated situation that apparently superseded the earlier land bridge vegetation of Beringia in the latest Pleistocene.
PARAGRAPH_XXO The Center for Northern Studies is currently working with the Smithsonian to develop a long-term research project in the Hovsgal region. This would involve research on the questions mentioned above in the following fashion. Taxonomic studies would be done on many of the important plant species, including molecular genetic studies, to determine how the plant populations relate to those of the true Arctic. Insect collections would be made and compared with the known insect faunas of ancient Beringia. We will also search for various kinds of deposits that will enable us to understand the changing Mongolian environment since (we hope) the late Pleistocene. Finally, the Smithsonian will be involved in major efforts to investigate the archaeological resources of the regions and preserve some of the more outstanding sites.

INSERT_PAGE_BREAK_HERE
TITLE_XXO A HIGH-RESOLUTION RECORD FROM SEDIMENT ANALYSES AND SEISMIC DATA FROM THE NW SHELF OF ICELAND, DURING THE TIME PERIOD 9.600 - 12.800 14C YEARS BP.

AUTHORS_XXO  LAFSDþTTIR, S•DýS (1); Geirsdþttir, Šslaug  (2); Andrews, John T. (3)

AUTHOR_1_XXO (1) Dept. of Geosciences, University of Iceland; olafsdot@colorado.edu
AUTHOR_2_XXO (2) Dept. of Geosciences, University of Iceland; age@hi.is
AUTHOR_3_XXO (3) INSTAAR and Dept. of Geol. Sciences, University of Colorado; andrewsj@spot.colorado.edu

PARAGRAPH_1_XXO The NW shelf of Iceland is an extremely sensitive area where the East Greenland current of polar origin and the warmer and saline North Atlantic current meet.  In 1999, a core was collected aboard the IMAGES cruise (MD99-2264) on the Marion Dufresne from the Djupall trough system (66° 40.74 N; 24° 11.76 W).  The core is 38m long and numerous AMS 14C dates show that it contains sediment that has been accumulating over the last 35 ky.  
PARAGRAPH_XXO In the summer of 2001, a new seismic reflection profile was obtained from the MD99-2264 core site.  The data was obtained with the WHOI SUBSCAN Chirp Sonar, which is a shallow water, high-resolution acoustic imaging system.  The system operates at frequencies between 0.5-16 kHz and is therefore able to provide very high-resolution (10s of cm resolution) subbottom profiling data up to 80 m thick.  The Djupall data clearly shows five different sedimentation units, erosional structures and tephra layers in the trough.  Comparison between the seismic reflection profile and the lithofacies from the MD99-2264 core agree perfectly.  
PARAGRAPH_XXO In this study we are focusing on a 7 m long part of the core, from 8-15 m.  In this succession we have three AMS 14C dating and also the Vedde tephra, which serves as a useful time marker.  According to the radiocarbon dates this interval corresponds to sedimentation during deglaciation (~12.800-9.600 14C years BP).  The mean sedimentation accumulation rate during this period is 220cm/1000 years.  However, in the beginning of the period (12.600 14C BP) the rate increases from 9 years/cm to 1 year/cm at the end of the interval.  This implies fluctuations during this interval with extremely high sedimentation rate around 9800 14C years BP.  Our interests in this study were to see if 1) data from grain size analyses would reflect environmental changes during this unstable period and, 2) to see if the grain size data would correlate to the IRD, total carbon and magnetic susceptibility data.  
PARAGRAPH_XXO Our results show considerable changes in the grain size, MS and total carbon, reflecting large fluctuations in sediment deposition.  In addition, pikes of ice rafted debris were followed by coarser sedimentation indicating a high-energy environment during the retreat periods of the glacier.  At the same depth interval in the Chirp profile, a strong seismic reflector is detected coinciding with Vedde tephra.  It also reflects an erosional boundary indicating changes in the paleobottom current system, which corresponds in time with the Younger Dryas chronozone.  Above the erosional boundary finer sediments accumulate indicating the beginning of Holocene sedimentation with stable bottom currents similar to the ones controlling the current system in Djupall trough today.

INSERT_PAGE_BREAK_HERE