Posted by: JohnnyRook | January 23, 2009

Wilkins Ice Bridge Narrows to 500 Meters

I’ve been following the fate of the Wilkins ice shelf for months and I confess that I expected that it would have broken up by now. The narrow bridge that connects Charcot and Latady Islands has shrunk to 500 meters wide at its narrowest point, while cracks at the base of the bridge have lengthened.

The last time a piece of the ice shelf broke off was, to everyone’s amazement, during the Antarctic winter, which is why it is surprising that it continues to hold together now, in the middle of the Antarctic summer.

According to RedOrbit:

We’ve come to the Wilkins Ice Shelf to see its final death throes,” glaciologist David Vaughan of the British Antarctic Survey (BAS) told Reuters after his red Twin Otter plane landed near the shelf’s narrowest section.

“It really could go at any minute,” he said, adding that the ice bridge could linger weeks or months.

The large, flat-topped ice shelf extends 65 ft. out of the sea off the Antarctic Peninsula, and is held together by a narrowing 25-mile ice strip that has dwindled to an hourglass shape of just 1640 ft. wide at its narrowest point.

In 1950, the shelf was over 60 miles wide, covering 6,000 square miles. Since then, temperatures on the Antarctic Peninsula have warmed by about 3 Celsius (5.4 Fahrenheit), the fastest rise anywhere in the southern hemisphere. Other parts of the continent show little sign of warming. [Actually, the latest research shows that that last sentence is not true.]

Here is some video of the current state of the ice shelf.

The disintegration of ice shelves does not substantially raise sea levels because the ice is floating and already mostly submerged by the ocean. But scientists are concerned that their loss will allow land-based ice sheets to move more rapidly, adding extra water to the seas.

And while Wilkins has almost no pent-up glaciers behind it, ice shelves further south restrain enormous volumes of ice.

“When those are removed the glaciers will flow faster,” Vaughan said.

“It’s very unlikely that our presence here is enough to initiate any cracks,” Vaughan said, referring to the hour he spent on the shelf, accompanied by BAS scientists and two Reuters reporters.

“But it is likely to happen fairly soon, weeks to months, and I don’t want to be here when it does.”

I will continue to monitor the status of the Wilkins and will provide updated posts as events warrant.

Related Posts:
Less Sea Ice in the Arctic, More in the Antarctic, and, of Course, the Denialists Get It All Wrong

“Webcam” From Space/Arctic Sea Ice Soon Gone: News From Both Poles

Greenland and Antarctic Glacier Retreat Linked

Greenland and Antarctic Glacier Retreat Linked

From North to South, the Whole Damn World is Melting

When Ice Shelves Collapse: A Brief Tutorial

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