Saturday, July 3, 2010

Northwest Passage or Arctic Ocean for Trans-Arctic Shipping

When all is said and done, the Northwest Passage may not be as important as we thought.

The Northwest Passage is the sea route from Baffin Bay to Alaska. In unusually warm summers, enough of the ice melts that ships can get through. It hasn’t been so easy in the last two summers, though, and this summer looks to follow the same pattern.

It is not that the ice is not melting. The problem is that ice is melting on the open ocean too, and fragments of ice from the Arctic Ocean are jamming up the straits that make up the Northwest Passage. With ice fragmenting so easily, the straits may not melt until the open ocean melts.

Yet at the rate things are going, that could happen this year. There was near-average ice extent in the Arctic region in March and April, which is a lot by post-2007 standards, but the widespread ice extent hid a rapidly declining volume of ice. According to estimates, the ice might have been the thinnest ever. Measured by extent, the ice melt in May was the fastest ever recorded, and the rapid melt has continued, creating a June ice map that looks like July. The ice extent for June is the lowest ever recorded. Barring a change in the weather, half of the remaining ice will melt in July and August, opening up usable shipping lanes across the open ocean for the month of September.

Even then, the Northwest Passage may or may not open. With so much ice melting and breaking up, loose ice could easily jam up any given strait. The open ocean may give ships more options for dodging whatever stray ice might still be floating around.