Ayles Ice Shelf

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Ayles Ice Shelf
Elevation	Sea Level
Location	Nunavut, Canada
Coordinates	83°1.5′N 77°33.5′W

Before: Ellesmere Island on July 12, 2002.

After: A NASA satellite image taken August 13, 2005 shows the collapse. The newly formed ice island forms only a small part of this picture, being the fragment very close to shore at the centre of the image. The island is ringed in the picture shown in this CBC article.

The Ayles Ice Shelf was one of six major ice shelves in Canada, all located on the northern coast of Ellesmere Island, Nunavut. The ice shelf broke off from the coast on August 13, 2005, forming a giant ice island 120 ft (37 metres) thick and measuring around 14 kilometers (9 miles) by 5 kilometers (3 miles) in size (approximately 66 square kilometers or 25.5 square miles in area or 2.6 km³ in volume). The oldest ice in the ice shelf is believed to be over 3,000 years old. The ice shelf was located at (83°1.5′N 77°33.5′W), approximately 800 kilometers (500 statute miles) south of the North Pole.

The Ayles Ice Shelf, like the nearby Mount Ayles, was named for the Arctic explorer Adam Ayles, who served under George Nares as the Petty Officer of HMS Alert in the British Arctic Expedition.^[1] A 1986 survey of Canadian ice shelves found that 48 square kilometers (3.3 cubic kilometers) of ice calved from the Milne and Ayles ice shelves between 1959 and 1974.^[2]

[edit] Breakup

On August 13, 2005, the entire shelf broke clear from the coast of Ellesmere, forming a new ice island. It is believed to be the largest shelf breakup of its kind in Canada in over 30 years.^[3] The event registered on seismometers in northern Canada, and it was verified via satellite imagery.

Within days of the breakup, the former shelf had drifted over 50 kilometers (30 mi) from Ellesmere Island before freezing into the sea ice. There is concern that when the sea ice melts in the spring, warm temperatures will release the former shelf, making it a hazard for ships and oil platforms in its drift path.^[4]

The breakup was noticed by the Canadian Ice Service at the time that it occurred, but it took a further 16 months to fully reconstruct the breakup sequence from past satellite images captured by MODIS, to determine the climatic conditions during the event, and for the event to garner public attention. The event, which has been linked to global warming, is similar to the 2002 breakup of the Larsen B Ice Shelf in Antarctica.

The speed of the breakup is also remarkable; it took less than an hour. Canada has lost approximately 90% of its ice shelves in the last hundred years.^[5]