Canadian Arctic Ice Sheet Nearly Size of Manhattan Breaks Off
By Adam Satariano
September 3, 2008

A 19-square-mile (50 kilometers) ice shelf attached to an island in Canada's northern arctic for thousands of years has broken from land, another sign of the effect of global warming, scientists said. Nearly the size of Manhattan, the 4,500-year-old Markham Ice Shelf separated from Ellesmere Island in early August and is now floating in the Arctic Ocean, said Luke Copeland, director of the Laboratory for Cryospheric Research at the University of Ottawa.

Copeland and fellow researchers were watching the ice shelf, which is about as tall as a 10-story building, using satellite imagery when cloud cover blocked the region for five days. When visibility returned, the mass was gone. "It was a complete shock," Copeland said in an interview. "Five days later it was completely gone. That's what was really amazing is that we lose it all in such a short period of time, within just a few days."'

The loss comes after last week's announcement by the National Snow and Ice Data Center that Arctic sea ice, which melts partially during each polar summer, had shrunk more this year than any other year except 2007. The Greenland Ice Sheet also has been losing mass, according to the conservation group WWF.

In January, the National Aeronautics and Space Administration said net loss of ice mass in Antarctica increased to 196 billion metric tons in 2006 from 112 metric tons a decade earlier. "It's part of the broader picture that things are changing very, very quickly," Copeland said. The United Nations Intergovernmental Panel on Climate Change last year said temperatures in the Arctic are increasing at almost twice the global rate. The warmer weather is melting ice in the sea and in Greenland, which contains enough water to raise global sea levels by 7 meters (23 feet).

Bloomberg News
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19-square-mile ice sheet breaks loose in Canada
By CHARMAINE NORONHA
September 4, 2008
Associated Press

TORONTO (AP) — A chunk of ice shelf nearly the size of Manhattan has broken away from Ellesmere Island in Canada's northern Arctic, another dramatic indication of how warmer temperatures are changing the polar frontier, scientists said Wednesday. Derek Mueller, an Arctic ice shelf specialist at Trent University in Ontario, told The Associated Press that the 4,500-year-old Markham Ice Shelf separated in early August and the 19-square-mile shelf is now adrift in the Arctic Ocean.

"The Markham Ice Shelf was a big surprise because it suddenly disappeared. We went under cloud for a bit during our research and when the weather cleared up, all of a sudden there was no more ice shelf. It was a shocking event that underscores the rapidity of changes taking place in the Arctic," said Mueller.

Mueller also said that two large sections of ice detached from the Serson Ice Shelf, shrinking that ice feature by 47 square miles — or 60 percent — and that the Ward Hunt Ice Shelf has also continued to break up, losing an additional eight square miles. Mueller reported last month that seven square miles of the 170-square-mile and 130-feet-thick Ward Hunt shelf had broken off.

This comes on the heels of unusual cracks in a northern Greenland glacier, rapid melting of a southern Greenland glacier, and a near record loss for Arctic sea ice this summer. And earlier this year a 160-square mile chunk of an Antarctic ice shelf disintegrated. "Reduced sea ice conditions and unusually high air temperatures have facilitated the ice shelf losses this summer," said Luke Copland, director of the Laboratory for Cryospheric Research at the University of Ottawa. "And extensive new cracks across remaining parts of the largest remaining ice shelf, the Ward Hunt, mean that it will continue to disintegrate in the coming years."

Associated Press
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I've seen a number of reports now saying that for the first time in more than 500 years the North Pole is now an island with navigable sea routes right around it although some indicate the sea passages will be extremely dangerous with heavy ice floes and the possibility of routes freezing over within hours.