Huge slice of Arctic ice could spell big trouble

TORONTO — A giant ice shelf has snapped free from an island in the Canadian Arctic, scientists said, citing climate change as a "major" reason for the event.

The chunk of ice could wreak havoc if it starts to float westward toward oil-drilling regions and shipping lanes next summer, a researcher said Friday.

The Ayles Ice Shelf broke clear in summer 2005 from the coast of Ellesmere Island, about 500 miles from the North Pole, but was only detected recently by satellite photos, said Luke Copland, assistant professor at the University of Ottawa's geography department.

It was the largest such break in nearly 30 years, casting an ice floe with an area of 25 square miles adrift in the Arctic Ocean, said Copland, who specializes in the study of glaciers and ice masses.

"The Arctic is all frozen up for the winter, and it's stuck in the sea ice about 30 miles off the coast," he said.

"The risk is that next summer, as that sea ice melts, this large ice island can then move itself around off the coast, and one potential path for it is to make its way westward toward the Beaufort Sea, and the Beaufort Sea is where there is lots of oil and gas exploration, oil rigs and shipping."

Warwick Vincent, of Laval University in Quebec City, who studies Arctic conditions, traveled to the newly formed ice island.

"This is a dramatic and disturbing event. It shows that we are losing remarkable features of the Canadian North that have been in place for many thousands of years," Vincent said. "We are crossing climate thresholds, and these may signal the onset of accelerated change ahead."

The ice shelf was one of six major shelves remaining in Canada's Arctic. They are packed with ice that is more than 3,000 years old.

"It is consistent with climate change," Vincent said, adding that the remaining ice shelves are 90 percent smaller than when they were discovered in 1906. "We aren't able to connect all of the dots ... but unusually warm temperatures definitely played a major role."

Laurie Weir, who monitors ice conditions for the Canadian Ice Service, was poring over satellite images when she noticed that the shelf had split and separated.

Weir notified Copland, head of the new global ice lab at the University of Ottawa, who began trying to find out what happened.

Using U.S. and Canadian satellite images, and seismic data — the event registered on earthquake monitors 155 miles away — Copland discovered that the ice shelf collapsed in early afternoon Aug. 13, 2005.

Copland said the speed with which climate change has affected the ice shelves surprised scientists.

"Even 10 years ago scientists assumed that when global-warming changes occur that it would happen gradually so that perhaps we expected these ice shelves just to melt away quite slowly," he said.

The break went undetected when it happened due primarily to the remoteness of the northern coast of Ellesmere Island.

Ice shelves in Canada's far north have decreased in size by up to 90 percent since 1906, and global warming likely played a role in the Ayles break, Copland said.

"It's hard to tie one event to climate change, but when you look at the longer-term trend, the bigger picture, we've lost a lot of ice shelves on northern Ellesmere in the past century and this is that continuing," he said.