Antarctic ice bridge collapse hailed as new sign of global warming

An ice bridge holding a vast Antarctic ice shelf in place has collapsed, providing new evidence of the extent of global warming, according to scientists.

Satellite images of the Wilkins Ice Shelf on the Antarctic Peninsula showed how the ice suddenly gave way.
The satellite picture, from the European Space Agency (ESA), showed that a 40 km (25 mile) long strip of ice believed to pin the Wilkins Ice Shelf in place had splintered at its narrowest point, about 500 metres wide.

"It's amazing how the ice has ruptured. Two days ago it was intact," David Vaughan, a glaciologist with the British Antarctic Survey, told Reuters.
"We've waited a long time to see this," he said.
The Wilkins, now the size of Jamaica or the U.S. state of Connecticut, is one of 10 shelves to have shrunk or collapsed in recent years on the Antarctic Peninsula, where temperatures have risen in recent decades apparently because of global warming.
The ESA picture showed a jumble of huge flat-topped icebergs in the sea where the ice bridge had been, pinning the Wilkins to the coast and running northwest to Charcot Island.
"Charcot Island will be a real island for the first time in history," Mr Vaughan said.
The loss of the ice bridge, jutting about 20 metres out of the water and which was almost 100 km wide in 1950, may now allow ocean currents to wash away far more of the Wilkins shelf.
"My feeling is that we will lose more of the ice, but there will be a remnant to the south," said Mr Vaughan. Ice shelves float on the water, formed by ice spilling off Antarctica, and can be hundreds of metres thick.
Cores of sediments on the seabed indicate that some of these ice shelves had been in place for at least 10,000 years.
"We believe the warming on the Antarctic Peninsla is related to global climate change, though the links are not entirely clear," Mr Vaughan said.
The loss of ice shelves does not affect sea levels - floating ice contracts as it melts and so does not raise ocean levels. But their loss can allow glaciers on land to slide more rapidly towards the sea, adding water to the oceans.