25 May 2005

Glaciers May Be Shrinking But Antarctic Ice Sheet Gains Mass

by Kate Melville

While some climate change research suggests that global sea levels are rising due to global warming and the shrinkage of glaciers, a new study in Science has found that the interior of the East Antarctic ice sheet is actually gaining mass.

Curt Davis, a researcher at the University of Missouri-Columbia, observed the ice sheet over a 10 year period using satellites and discovered that the ice sheet's interior was gaining mass by about 45 billion tons per year. The interior of the ice sheet is the only large terrestrial ice body that is likely gaining mass rather than losing it, said Davis. "Many recent studies have focused on coastal ice sheet losses and their contributions to sea level rise," Davis said. "This study suggests that the interior areas of the ice sheet also can play an important role. In particular, the East Antarctic ice sheet is the largest in the world and contains enough mass to raise sea level by more than 50 meters. Thus, only small changes in its interior can have a significant affect on sea level."

The study suggests that increased precipitation was the likely cause of the gain. The most recent U.N. Intergovernmental Panel on Climate Change confirmed this when it reported that Antarctica would likely gain mass due to increased precipitation in a warming climate. Interestingly, the study made no direct link to global warming. "We need more ice core measurements from East Antarctica to determine if this increased precipitation is a change from the past or part of natural variability," said Joe McConnell, co-author of the study. "Ice sheet response to climate change is a complex process that is difficult to measure and even more difficult to predict. The overall contribution of the Antarctic ice sheet to global sea-level change will depend on how mass changes in the ice sheet's interior balance mass changes from the coastal areas," concluded Davis.

Source: Media Release - University of Missouri-Columbia