Several large outlet glaciers accelerated during this same period, and snow accumulation increases cannot compensate for the enhanced mass discharge. Stearns and Hamilton studied ice dynamics on the coastal portions of southeast Greenland's Kangerdlugssuaq and Helheim glaciers, which have each lost at least 51 cubic kilometers [13 trillion U.S. gallons] of ice each year since 2001. Through analysis of digital elevation models derived from satellite images taken over the last five years, the authors show that the main contribution to this ice loss was dynamic thinning caused by the acceleration in flow of these glaciers. This thinning destabilized the ice mass, making it more susceptible to calving and melting. Based on their data, the authors estimate that together these glaciers have actually lost about 122 cubic kilometers [32.2 trillion U.S. gallons] each year since 2001, accounting for half the total ice mass lost from the entire Greenland ice sheet over this time.
Posted February 23rd, 2007 by harminka
