Wednesday, January 21, 2009

HUGE ANTARCTIC ICE SHELF ON BRINK OF COLLAPSE

Alister Doyle, 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. . . 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. . .

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. . .

In total, about 25,000 sq km of ice shelves have been lost, changing maps of Antarctica. Ocean sediments indicate that some shelves had been in place for at least 10,000 years.