Ottawa, September 3: A team of researchers has reported that massive pieces of Canada’s northern ice shelf broke away in early August, and are now floating free in the Arctic Ocean.

According to a report in the Globe and mail update, the 50-square-kilometre Markham shelf, located on the northern coast of Ellesmere Island, is now floating free in the Arctic ocean along with a larger portion of the Serson shelf.

Meanwhile, remnants of the Ward Hunt ice shelf, which attracted international publicity when it collapsed in July, continue to float away from the Ellesmere shore.

Collapses like those this summer worry scientists since shelf ice, unlike more ephemeral sea ice, can be as much as 4,500 years old and 40 metres thick.

According to Dr. Derek Mueller, the Roberta Bondar Fellow in Northern and Polar Studies at Trent University in Peterborough, Ontario, recent losses of shelf ice - totaling 214 square kilometers this summer in the Canadian north - are almost certainly the result of global warming.

“You just can’t have ice shelves in a warm climate,” he said. “You can’t link any one event to climate change, but we can certainly link patterns,” he added.

Satellite photographs show that the extent of sea ice around Ellesmere Island has also been significantly reduced. Where once Arctic waters were frozen right up to the edge of the island, there is now a substantial expanse of open water.

The news that large pieces of shelf ice have been lost comes just after Canadian Prime Minister Stephen Harper’s tour of the high Arctic, where he has promised to expand Canada’s military presence and boost natural resource exploration. (ANI)