Huge cracks and areas of open water have been appearing near the Ayles Ice Island in recent weeks, says Luke Copland, an ice specialist at the University of Ottawa, who is flying to the island this weekend for a look. He intends to plant a tracking device on the island so what he calls a "sentinel" of climate change can be followed in real time as it travels the Arctic.

The ice island formed in August 2005 when the Ayles Ice Shelf, which was between 3,000 and 4,500 years old, cracked off Ellesmere Island and slid into the sea. It is 66 square kilometres in area and between 30 and 40 metres thick, making it the largest ice island in Canada in 30 years.

Copland and his colleagues at the Canadian Ice Service say the island could soon start moving because of the remarkable ice loss occurring in the nearby Lincoln Sea at the northeastern tip of Ellesmere.

The sea is losing vast amounts of ice because the Nares Strait ice bridge, which normally forms between Ellesmere Island and Baffin Island in December -- and prevents the Arctic ice from moving south, did not form this winter. The loss is also generating enormous fractures in the polar pack ice, some of them hundreds of kilometres long.

Large parts of the Lincoln Sea "have essentially been ice-free for the last month or two, which is extremely unusual," says Copland.

Huge slabs of thick, hard multi-year ice up to 90-kilometres across have been breaking free in the Lincoln Sea and sailing south, bound for the waters off Labrador and Newfoundland.

Multi-year ice is harder, denser and more dangerous to navigation than ice that forms and melts yearly.

"It can actually punch a hole through the hull of a ship," says Trudy Wohlleben of the ice service. "It's flushing down Nares Strait, like a toilet flushing."

The ice is coming down and breaking up as it travels through Baffin Bay and the Labrador Sea. Some chunks have been spotted as far south as Fogo Island off Newfoundland.

The tracking device Copland is installing on the ice island will transmit temperatures and pressure readings as well as its position to a communications satellite every five minutes.

"The neat thing about the beacon is you'll be able to see the movement in real time," he says.

It will soon be possible to check on the beacon and the island from any computer. In the past, large ice islands have migrated around the Arctic for 40 to 50 years.

The big question now is whether Ayles Island, which is expected to head toward the southwest, will become stuck in Canada's Arctic islands, or head for the Beaufort Sea -- a prospect that worries oil companies.

"It's really woken them up," says Copland.

Representatives from one major U.S. oil company recently flew to Ottawa to meet with the ice forecasters and researchers to discuss the risk to drilling operations off the North Slope of Alaska.

Douglas Bancroft, director of the Canadian Ice Service, says the risk is low but real.

"When you have something the size of Manhattan, 100-feet thick and 3,000 years old, it has some interesting strengths," says Bancroft. "It is something you want to bring in some very serious engineering talent to deal with."

The ice island is too big to be towed, a tactic often used when icebergs are a concern. Wohlleben says explosives are sometimes used to divert icebergs, and that might be a possibility if the island ends up on a collision course with oil operations.

Bancroft stresses there would have to be extensive discussions with other agencies before anyone resorted to explosives.

There would be plenty of warning if the island heads for the Beaufort, and ice forecasters say it would likely take years to get there.

Meanwhile, the island is seen as such an icon of climate change that it continues to attract international attention. A BBC TV crew is flying to the island this weekend with Copland and Derek Mueller of the University of Alaska in Fairbanks, who are documenting the demise of the ancient ice.

The Ayles Ice Shelf was one of six ice shelves left in Canada, remnants of a vast icy fringe that covered the top end of Ellesmere for eons.

The scientists say they can't prove human-induced climate change caused the Ayles collapse, but they suspect it was a factor.

Some leading ice scientists are predicting the Arctic could be ice-free in summer months as early as 2040.

The outlook for the remaining ice shelves, Copland says, is "pretty grim."