Ice breaks in Canada; may pose a shipping peril
Global warming may be a cause; west move feared
CALGARY, Alberta -- A chunk of ice that once was bigger in area than Manhattan broke from an ice shelf in Canada's far north and could cause havoc if it starts to float westward toward oil-drilling regions and shipping lanes next summer, a researcher said yesterday.
Global warming may be one cause of the break of the Ayles Ice Shelf at Ellesmere Island, which occurred in August 2005, but was detected only recently by satellite photos, said Luke Copland, assistant professor at the University of Ottawa.
It was the largest such break in nearly three decades, 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 mass is 19 square miles.
"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."
The break went undetected when it happened, primarily because of the remoteness of the northern coast of Ellesmere island, which is only about 500 miles from the North Pole.
The speed of the crack and driftoff shocked scientists. Satellite images showed the 9-mile-long crack, then the ice floating about 0.6 miles from the coast, within about an hour, Copland said.
"You could stand at one edge and not see the other side, and for something that large to move that quickly is quite amazing," he said.
Copland said the break was probably attributable to a combination of low accumulations of sea ice around the edges of the mass as high winds blew it away, as well as one of the ocean's warmest water temperatures on record. The air temperature of the Arctic was about 5.4 degrees above average in summer 2005, he said.
Ice shelves in Canada's far north have shrunk by as much as 90 percent since 1906, and global warming probably 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. "And this is the biggest one in the last 25 years."
The ice mass was one of six major shelves that are remaining in Canada's Arctic. The shelves, which are packed with ice that is more than 3,000 years old, float on the sea but are connected to land.
Warwick Vincent of Laval University in Quebec, who studies Arctic conditions, traveled to the newly formed island and said he could not believe what he had seen.
"This is a dramatic and disturbing event," he said. "It shows that we are losing remarkable features of the Canadian North that have been in place for many thousands of years.
"We are crossing climate thresholds, and these may signal the onset of accelerated change ahead,"
"We aren't able to connect all of the dots . . . but unusually warm temperatures definitely played a major role," Vincent said.
Material from the Associated Press was included in this report.