Published: Sept. 21, 2016

Measuring just how much mass a glacier is losing—through melting and calving—is no easy task. While there’s plenty of satellite data from space, scientists haven’t had access to much local, on-the-ground observation, which is the sort of information that’s necessary to more accurately measure glacial mass loss.

But now a team of scientists, including CIRES’ Mike Willis, have put a series of GPS systems in place that give them the kind of data they need. Using that information, they find that previous estimates of mass loss from the Greenland Ice Sheet—already known to be shrinking—may be underestimates. Their study is out today in Science Advances.

Willis, who’s also a glaciologist with the University of Colorado Boulder’s Department of Geological Sciences, has spent decades studying the Earth’s ice sheets, including Greenland’s. Over the past two decades, the Greenland Ice Sheet has lost mass as glaciers around the edge flow faster into the ocean and melting in the interior increases in area and duration. Recent work comparing old aerial photographs with modern measurements of the ice show that the basins of the southeast, east and northwest of the ice sheet have contributed to 77 percent of its total mass loss to the ocean over the last century.

Read the full story on the CIRES website.