Chilling images of ice-shelf collapsing in the heat

March 26th, 2008 - 4:24 pm ICT by admin  

New York, March 26 (IANS) A US satellite has captured chilling images of over 400 square kilometres of Antarctica’s massive Wilkins Ice Shelf collapsing because of rapid climate changes. The area is part of the much larger shelf of nearly 13,000 square kilometres that is now supported only by a narrow strip of ice between two islands.

“If there is a little bit more retreat, this last ‘ice buttress’ could collapse and we’d likely lose about half the total ice shelf area in the next few years,” warned Ted Scambos of the University of Colorado at Boulder.

In the past 50 years, the western Antarctic Peninsula has experienced the biggest temperature increase on earth, rising by 17.27 degrees Celsius per decade.

The university said NASA’s Moderate Resolution Imaging Spectroradiometer captured the images.

“We believe the Wilkins has been in place for at least a few hundred years, but warm air and exposure to ocean waves are causing a break-up,” said Scambos, who first spotted the collapse earlier this month.

Satellite images indicate the Wilkins began its collapse on Feb 28. Data revealed that a large iceberg, measuring 41.03 by 2.41 kilometres, fell away from the ice shelf’s southwestern front, triggering a runaway disintegration of 569.79 square kilometre of the shelf interior.

The Wilkins Ice Shelf is a broad sheet of permanent floating ice on the southwest Antarctic Peninsula roughly 1,600 kilometres south of South America.

The edge of the shelf crumbled into the sky-blue pattern of exposed deep glacial ice that has become characteristic of climate-induced ice shelf break-ups such as the Larsen B ice shelf break-up in 2002, said Scambos.

A narrow beam of intact ice about 5.95 kilometres wide was protecting the remaining shelf from further break-up as of March 23, he added.

Scientists track ice shelves and study collapses carefully because some of them hold back glaciers, which, if unleashed, can accelerate and raise sea levels, Scambos said.

“The Wilkins disintegration won’t raise the sea level because it already floats in the ocean, and few glaciers flow into it. However, the collapse underscores that the Wilkins region has experienced an intense melt season.”

With Antarctica’s summer melt season drawing to a close, scientists do not expect the Wilkins to further disintegrate in the next several months.

“This unusual show is over for this season,” Scambos said. “But come January, we’ll be watching to see if the Wilkins continues to fall apart.”

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