Thursday, August 5, 2010

Greenland Ice Sheet Melting at Record Rate

Two satellite images provided by NASA and taken on July 28 and Aug. 5, show the Petermann Glacier in Northern Greenland. A giant ice island, seen in image at right, has broken off the Petermann Glacier. The floating ice sheet covers 100 square miles (260 sq. kilometres) - more than four times the size of Manhattan Photo: AFP/NASA

The University of St. Andrews team said 106 sq. mi. broke away from the Petermann Glacier at the beginning of August.

The massive ice island is is the largest single area loss observed for Greenland and suggests the effect of rising temperatures is affecting the Arctic faster than anticipated.

The finding immediately raises fears about the long term effect on rising sea levels and ultimately ‘positive feedbacks’ as water absorbs more heat than ice, therefore speeding up the warming effect.

Dr. Richard Bates, who is monitoring the ice alongside researchers from America, said the expedition had expected to find evidence of melting this year after “abnormally high” temperatures in the area. Climate change experts say that globally it has been the warmest six months since records began.

But he was “amazed to see an area of ice three times the size of Manhattan Island had broken off.

“It is not a freak event and is certainly a manifestation of warming. This year marks yet another record breaking melt year in Greenland; temperatures and melt across the entire ice sheet have exceeded those in 2007 and of historical records.”

The Petermann glacier, one of the largest glaciers in the northern hemisphere, has now retreated to a level not seen since 1962.

Dr. Bates and his team are currently in Greenland trying to determine whether the breakup has led to a further acceleration and thinning of ice.

The geophysicists uses time-lapse cameras overlooking the glacier from the top of its towering 900 m cliffs, as well as risking their lives trying to get as close as possible to the icebergs.

“It is very difficult logistically and expensive to get back,” he said. “The idea at present is to try and sail to close to the glacier with helicopter support on the passage up there; and, then for getting around when there. It could be a bit tricky doing this as it’s not only a long way; but, there will be ever-increasing ice to negotiate on the way north,” he said.

The new research comes as scientists from Pennsylvania State University warned that temperature rise of between 2C and 7C would cause the entire ice mass of Greenland to melt, resulting in 23 ft rise in sea level.

Via Telegraph

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