Alaska Glaciers' Net Ice Loss 75 Gigatons/Yr - Antarctica 159 Gigatons/Yr - Faster Than Expected

In a new study, scientists with the University of Alaska at Fairbanks and several other institutions report a staggering finding: Glaciers of the United States’ largest — and only Arctic — state, Alaska, have lost 75 gigatons (a gigaton is a billion metric tons) of ice per year from 1994 through 2013.

For comparison, that’s roughly half of a recent estimate for ice loss for all of Antarctica (159 billion metric tons). It takes 360 gigatons of ice to lead to one millimeter of sea level rise, which implies that the Alaska region alone may have contributed several millimeters in the past few decades.

“Despite Greenland’s ice covered area being 20 times greater than that of Alaska, losses in Alaska were fully one third of the total loss from the ice sheet during 2005-2010,” wrote the authors, led by Chris Larsen of the University of Alaska at Fairbanks’s Geophysical Institute. The study was published in Geophysical Research Letters.

The paper used data from airborne altimeters as part of NASA’s Operation IceBridge to examine 116 Alaska glaciers, including both coastal or “tidewater” glaciers, but also glaciers that terminate in lakes or on land. The examined glaciers represented 41 percent of the total area of glaciers in the Alaska region, which the study defined as also including parts of British Columbia and the Yukon Territory. Then calculations were performed to estimate mass loss for the whole of the region’s glaciers.

“This is the first estimate ever where we’ve gone glacier by glacier through the whole region, all 25,000 plus glaciers are estimated individually, and then we sum them up,” says Shad O’Neel, a study co-author with the U.S. Geological Survey. And the result in terms of total glacial ice loss, he says, is that “we’re getting a bigger number than the community had thought before.”

EDIT

http://www.washingtonpost.com/news/energy-environment/wp/2015/06/17/alaskas-glaciers-are-now-losing-75-billion-tons-of-ice-every-year/