This is getting to be a habit. Recently we had icebergs being sighted off the coast of New Zealand, and now, on a far larger scale, we have a 66 square kilometre ice shelf breaking free in northern Canada.

"It really is incredible," says Warwick Vincent of Laval University, one of the few people to have laid eyes on the scene. "It's like a cruise missile has come down and hit the ice shelf."

The breakup was so powerful, earthquake monitors 250 kilometres away picked up the tremors as the 3,000- to 4,500-year-old shelf tore away from its fjord on Ellesmere. It broke up 16 months ago, but no one was present to see it. The scientists say they are only now releasing details after piecing together what happened using seismic monitors and Canadian and U.S. satellites....

The Ayles Ice Shelf was one of six ice shelves left in Canada, remnants of a vast icy fringe that used to cover the top end of Ellesmere. Scientists consider the Canadian shelves, about 800 kilometres south of the North Pole, sentinels that reflect the accelerating change in the Arctic.

The shelves are 90 per cent smaller than they were when Arctic explorer Robert Peary crossed them in 1906. And the Ayles ice shelf can now be erased from Canada's maps. "It no longer exists," Vincent says....

Researchers say there are many more in store. Last week a Canada-U.S. team predicted the Arctic Ocean could be devoid of summer ice as early as 2040, and possibly sooner. - Edmonton Journal