Antarctica Melting From Below
Jennifer A. Kingson, The New York Times
Early Antarctic explorers used all sorts of colorful words for icebergs — “growlers,” “bergy bits” — as well as the geological term “calved” for when a wall of ice would break noisily from the Antarctic coastline and start floating north. (Some wrote in their diaries that they could tell how recently an iceberg had calved by how degraded it looked).
More recently, the calving of enormous icebergs, some the size of Delaware, has been blamed for the worrisome loss of ice from the Antarctic continent. Now, a new paper contends there is more to the story: Warmer oceans are melting the ice shelves from below, causing just as much ice loss as calving, if not more.
The “basal melt” phenomenon “accounted for 55 percent of all Antarctic ice shelf mass loss from 2003 to 2008, an amount much higher than previously thought,” according to NASA, which was involved in the study. The authors say that theirs is the first comprehensive survey of Antarctic ice shelves and that it could help predict rises in sea levels.
“The traditional view on Antarctic mass loss is it is almost entirely controlled by iceberg calving,” said Eric Rignot of NASA’s Jet Propulsion Laboratory and the University of California, Irvine. “Our study shows melting from below by the ocean waters is larger, and this should change our perspective on the evolution of the ice sheet in a warming climate.”
