On thin ice

Glaciers on the Antarctic Peninsula are thinning and speeding up, according to new research by the British Antarctic Survey. They tracked 300 glaciers using aerial and satellite imagery, and report that 87% are retreating. Ice flow has speeded up by 12% from 1993 to 2003. From the BAS press release:

These observations – that echo recent findings from coastal Greenland – indicate that the cause is melting of the lower glaciers, which flow directly into the sea. As they thin, the buoyancy of the ice can lift the glaciers off their rock beds, allowing them to slide faster.

BBC coverage here.

At the other end of the planet, Reuters has been blogging (here and here) the activities of Koni Steffen of the University of Colorado and Jay Zwally from NASA as they make their annual visit to the Swiss Camp research post high on the Greenland ice sheet. Asked if he thought the IPPC’s fourth report underestimated future sea level increase, Steffen did not pull any punches:

I think it definitely underestimated. We complained heavily before it was released and that’s why they added a few lines that if there is a dynamic response of ice sheets the upper uncertainty might be higher. That tells you that the current IPCC report only takes into account the current understanding. We can model melt but we cannot model the dynamics.

And that’s why I keep covering this stuff…

Meanwhile, two Belgian explorers have been walking across the Arctic from Siberia to Greenland, taking snow measurements to help calibrate a new ESA satellite. ESA were able to help them to avoid early sea ice break-up to the northwest of Greenland in the Lincoln Sea. Story here, with some very cool animated pix of sea ice. For a look at the ice today, go to the NSIDC’s sea ice snapshot. Considerable thinning north of Alaska, where last year there was an unusual polynya. Cryospshere Today shows the same thing.

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