A huge ice mass with an area of 25 square miles (66 square km) has broken off the Ayles Ice Shelf at Ellesmere Island, indicating further sign of the incredible rate at which polar ice is now melting because of global warming.
The huge shelf collapse, which is viewed by the scientist as the largest event of its kind in 30 years, occurred in August 2005 but was not witnessed by any one. And, the scientists noticed the occurrence of this dramatic event only recently, when they looked at US and Canadian satellite images, as well as data from seismic monitors, said Luke Copland, assistant professor at the University of Ottawa's geography department.
The Ayles ice shelf, which could be up to 4,500 years old, has broken clear from the coast of Ellesmere Island, about 800 kilometres south of the North Pole in the Canadian Arctic, Copland, who is also the head of the new global ice laboratory at Ottawa University said Thursday.
The broken shelf, which is between 30 and 40 metres thick, has formed a floating ice island and could pose a serious threat to oil platforms in its drift path.
"The Arctic is all frozen up for the winter and (the floe) it's stuck in the sea ice about 50 km (30 miles) off the coast," Copland 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."
Contrary to ice sheets, which are wholly land-based, ice shelves float on the sea, but remain connected to land. Currently, only five Canadian ice shelves remain connected to land, and measurements show they are 90% smaller than they were in 1906.
Professor Warwick Vincent of Laval University in Quebec City, who studies Arctic ecosystems, traveled to the newly formed ice island and was surprised after seeing such a dramatic collapse. "It's like a cruise missile has come down and hit the ice shelf," he said.
Copland held a combination of low accumulations of sea ice around the edges of the ice mass, as well as the Arctic's warmest temperatures on record responsible for the dramatic and disturbing incidence.
The temperature of the region was 3 degrees Celsius (5.4 degrees F) above average in the summer of 2005, he said.
This year, the world got the clearest sign of global warming through several reports on Arctic ice indicating massive surge in disappearance of region’s sea ice.
In September, two NASA reports, one from the Jet Propulsion Laboratory in California and the other from the Goddard Space Flight Centre, in Maryland, by using different satellite monitoring technologies showed how fast the winter sea ice is disappearing over the past two years.