News Source: 
UW Today
May 12, 2014

The West Antarctic Ice Sheet, which holds enough water to raise global seas by several feet, is thinning. Scientists have been warning of its collapse, based on theories, but with few firm predictions or timelines.

University of Washington researchers used detailed topography maps and computer modeling to show that the collapse appears to have already begun. The fast-moving Thwaites Glacier will likely disappear in a matter of centuries, researchers say, raising sea level by nearly 2 feet. That glacier also acts as a linchpin on the rest of the ice sheet, which contains enough ice to cause another 10 to 13 feet (3 to 4 meters) of global sea level rise. The study is published May 16 in Science. (A separate study, to be published in Geophysical Research Letters, comes to a similar conclusion.)

“There’s been a lot of speculation about the stability of marine ice sheets, and many scientists suspected that this kind of behavior is under way,” said lead author Ian Joughin, a glaciologist at the UW’s Applied Physics Laboratory. “This study provides a more quantitative idea of the rates at which the collapse could take place.”