The Greenland ice sheet’s contribution to sea level rise increased from 0.23 millimeters [0.0091 inches] per year in 1996 to 0.57 millimeters [0.022 inches] per year in 2005. 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.

Title: Rapid volume loss from two East Greenland outlet glaciers quantified using repeat stereo satellite imagery

Authors: Leigh A. Stearns and Gordon S. Hamilton: Climate Change Institute, University of Maine, Orono, Maine, U.S.A.

Source: Geophysical Research Letters (GRL) paper 10.1029/2006GL028982, 2007