Friday, March 28, 2008

Antarctic Ice Shelf Collapses

An image of the Wilkins Ice Shelf disintegration taken from the British Antarctic Survey's Twin Otter aircraft reconnaissance flight. Credit: Jim Elliott, British Antarctic Survey

Biggest news (no pun intended) of my week off is the collapse of a portion of the Wilkins Ice Shelf in Antarctica. Variously described as "seven times the size of Manhattan" (National Geographic), "the size of the Isle of Man" (BBC News), "bigger than the city of Montreal" and "twice the size of Prince Edward Island" (AP/The Globe and Mail), and "the size of Northern Ireland" (Independent uk), the piece that collapsed is merely the edge of the larger Wilkins Ice Shelf which is "'hanging by a thread' and may soon break up". British scientists predicted the collapse in 1993, but they thought it would take 30 years; it took 15.

The Antarctic peninsula, which stretches north from the frozen continent towards South America, has experienced unprecedented warming over the past 50 years.

Six other ice shelves have already been lost entirely — the Prince Gustav Channel, Larsen Inlet, Larsen B, Wordie, Muller and Jones shelves.

But the Wilkins shelf is farther south than other ice that has retreated, so should be better protected by colder temperatures.

Vaughan said: "It's bigger than any ice shelf we've seen retreating before, and in the long term it could be a taste of other things to come. It is another indication of the impact that climate change is having on the region."

During the break-up, the Wilkins Ice Shelf broke into a sky-blue pattern of exposed deep glacial ice. This true-color image of the Wilkins Ice Shelf was taken by NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on March 6, 2008. Credit: National Snow and Ice Data Center

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