Sunday, March 4, 2012

Ellesmere Ice Shelf

Late last year and early this year, various news stories reported the demise of the Ayles Ice Shelf, Ellesmere Island. On Dec. 29, 2006, National Geographic reported Giant Ice Shelf Breaks Off in Canadian Arctic and on Jan 4, 2007, CNN reported the story. The catastrophe actually occurred in August 2005, but no one noticed reported it until 16 months later.

From the story:

The mass of ice broke clear 16 months ago from the coast of Ellesmere Island, about 800 kilometers (497 miles) south of the North Pole, but no one was present to see it in Canada’s remote north. Scientists using satellite images later noticed that it became a newly formed ice island in just an hour and left a trail of icy boulders floating in its wake. (Watch the satellite images that clued in ice watchers) ..

The event registered as a small earthquake on instruments stationed 150 miles (250 kilometers) away, Warwick Vincent of Quebec’s Laval University told the CanWest News Service.

The Washington Post reported the story here showing the following picture from NASA. The Ayles ice shelf is visible in the center of the photograph at the lower part of the open water. They reported:

Within days of breaking free, the Ayles Ice Shelf drifted about 30 miles offshore before freezing into the sea ice.

A specialist scientist (Vincent) said that such an event was unprecedented in the tennnnnnnnnn years that he had been studying the area.

Interestingly, Hattersley-Smith 1967 (Arctic Circular 17, 13-14 noted up in Jeffries 1986) had previously observed that the Ayles Ice Shelf no longer existed. Jeffries 1986: