Monday, January 19, 2009

Antarctic ice shelf set to collapse due to warming

Alister Doyle in Reuters: A huge Antarctic ice shelf is on the brink of collapse with just a sliver of ice holding it in place, the latest victim of global warming that is altering maps of the frozen continent. "We've come to the Wilkins Ice Shelf to see its final death throes," David Vaughan, a glaciologist at the British Antarctic Survey (BAS), told Reuters after the first -- and probably last -- plane landed near the narrowest part of the ice.

The flat-topped shelf has an area of thousands of square kilometers, jutting 20 meters (65 ft) out of the sea off the Antarctic Peninsula. But it is held together only by an ever-thinning 40-km (25-mile) strip of ice that has eroded to an hour-glass shape just 500 meters wide at its narrowest. In 1950, the strip was almost 100 km wide.

"It really could go at any minute," Vaughan said on slushy snow in bright sunshine beside a red Twin Otter plane that landed on skis. He added that the ice bridge could linger weeks or months. The Wilkins once covered 16,000 sq km (6,000 sq miles). It has lost a third of its area but is still about the size of Jamaica or the U.S. state of Connecticut. Once the strip breaks up, the sea is likely to sweep away much of the remaining ice….

This highly detailed image from the Taiwanese Formosat-2 satellite shows the different sizes, shapes, and textures of the ice fragments on March 8, 2008. NASA