Antarctic Ice Shelf Collapses

A large Antarctic ice shelf in an area which is warming faster than the global average has collapsed with "staggering" rapidity, British scientists said Tuesday.

The shelf designated as Larsen B, 650 feet thick and with a surface area of 1,250 square miles, has collapsed into small icebergs and fragments, the British Antarctic Survey said.

The collapse was first detected on satellite images earlier this month by Ted Scambos of the National Snow and Ice Data Center at the University of Colorado.

"In 1998, BAS predicted the demise of more ice shelves around the Antarctic peninsula. Since then, warming on the peninsula has continued and we watched as piece-by-piece Larsen B has retreated," said David Vaughan, a glaciologist at the British Antarctic Survey.

"We knew what was left would collapse eventually, but the speed of it is staggering. Hard to believe that 500 million billion tons of ice sheet has disintegrated in less than a month."

In the past half century, the Antarctic Peninsula has warmed by 4.5 degrees Fahrenheit, much faster than mean global warming, the Survey said. As a result, five ice shelves which extend out over the ocean have retreated.

After the collapse was detected, Argentinian glaciologist Pedro Skvarca arranged for aircraft observations to confirm the collapse, the Survey said.

The British Antarctic Survey research ship James Clark Ross also navigated through the icebergs to take photographs and samples.