Arctic

Giant sheets of ice totaling almost 8 square miles broke off an ice shelf in the Canadian Arctic last week, and more could follow this year, scientists said Tuesday. The ice broke away from the shelf on small Ward Hunt Island, just off giant Ellesmere Island in one of the northernmost parts of Canada. It was the largest fracture of its kind since the nearby Ayles ice shelf, which measured 25 square miles, broke away in 2005.

Four miles south of the Arctic Circle, the morning sky is streaked with apricot. Frozen rivers split the tundra of the Seward Peninsula, coiling into vast lakes. And on a silent, wind-whipped pond, a lone figure, sweating and panting, shovels snow off the ice. The young woman with curly reddish hair stops, scribbles data, snaps a photo, grabs a heavy metal pick and stabs at white orbs in the thick black ice.

I am beluga bait. Bobbing at the end of a rope tied around my feet, I am being slowly towed in the wake of a Zodiac, a small, inflatable boat, through the icy waters of Hudson Bay. Clad in a partly inflated rubber dry suit, I look like a Michelin Tire Man who has sprouted a snorkel as I peer into the murky brown, tannin-stained cocktail of salt and freshwater. I have come all the way to far northern Manitoba, Canada, to snorkel with beluga whales that, if they do appear out of the gloom, will likely scare the daylights out of me. As my heart races, I remember my guide suggesting I sing to attract these most vocal of whales, known as "canaries of the sea" for their high-pitched songs and rhythmic clicks.

Long-term climate records from the Arctic provide strong new evidence that human-caused global warming can override the Earth's natural heating and cooling cycles, U.S. researchers reported this week in the journal Science. For more than 2,000 years, a natural wobble in the Earth's axis has caused the Arctic region to move farther away from the sun during the region's summer, reducing the amount of solar radiation it receives. The Arctic is now 600,000 miles farther from the sun than it was in AD 1, and temperatures there should have fallen a little more than 1 degree Fahrenheit since then.

Most days in Nome, you're not likely to run into anybody you didn't see at the Breakers Bar on Friday night. More than 500 roadless miles from Anchorage, rugged tundra and frigid Bering Sea waters have a way of discouraging visitors. So it was a big deal when the World, a 644-foot residential cruise ship with condos costing several million dollars apiece, dropped anchor during the summer for a two-day look-see. "We never had a ship anywhere near this size before," Chamber of Commerce director Mitch Erickson said.

In an attempt to head off a major commercial fishing march into the Arctic, the Obama administration declared a moratorium on expanded fishing in the still-uncharted waters of the far north. U.S. Commerce Secretary Gary F. Locke banned the expansion of most commercial fishing beyond the Alaskan coast until new scientific studies can determine what fish stocks exist and how crucial they are to maintaining a fragile Arctic ecosystem already under stress. The order, recommended by the North Pacific Fisheries Management Council in February, restricts future commercial fishing for finfish and shellfish in nearly 200,000 square miles of the Beaufort and Chukchi seas.

There's more to the recent dramatic and alarming thawing of the Arctic region than can be explained by human-caused global warming alone, a new study says. Nature is pushing the Arctic to the edge too. There's a natural cause that may account for much of the Arctic warming, which has melted sea ice, ice sheets and glaciers, according to a study published Thursday in the journal Nature. New research points a finger at a natural and cyclical increase in the amount of energy in the atmosphere that moves from south to north around the Arctic Circle.

In considering the various arguments for and against global warming, perhaps one of the strongest supporting the proponents' position appeared in Monday's Business section ("Ships intrude on Arctic's warming waters," Global Report, March 10). The story noted that ship owners have ordered 152 reinforced ships for use in newly opened northern waters. At a conservative $100 million each, that's $15 billion of one industry's capital invested on the assumption the Arctic warming trend will continue.

Prime Minister Stephen Harper said his government was taking steps to bolster Canada's presence in the Arctic amid concerns about Russian intentions there. Harper charged that Russia had been showing signs of flaunting international norms in the region. "That's obviously why we're taking a range of measures, including taking military measures to strengthen our sovereignty in the north," Harper told reporters in Quebec. Harper has vowed to build two new military facilities in the Arctic.

The Bush administration's authorization of a major new offshore oil drilling program in the Arctic Ocean was dealt a serious setback Thursday when a federal appeals court ruled the plan did not adequately consider the effect on bowhead whales and the native villagers who make their living from the frigid coastal waters. Ruling on the first of several major new projects for tapping oil and gas deposits from the Arctic floor, the U.S.