Friday, June 13, 2008

Wilkins Ice Shelf Continues to Break up...Even in Winter


Wilkins Ice Shelf has experienced further break-up with an area of about 160 km² breaking off from 30 May to 31 May 2008. ESA's Envisat satellite captured the event – the first ever-documented episode to occur in winter.

Wilkins Ice Shelf, a broad plate of floating ice south of South America on the Antarctic Peninsula, is connected to two islands, Charcot and Latady. In February 2008, an area of about 400 km² broke off from the ice shelf, narrowing the connection down to a 6 km strip; this latest event in May has further reduced the strip to just 2.7 km.

This animation, comprised of images acquired by Envisat's Advanced Synthetic Aperture Radar (ASAR) between 30 May and 9 June, highlights the rapidly dwindling strip of ice that is protecting thousands of kilometres of the ice shelf from further break-up.

According to Dr Matthias Braun from the Center for Remote Sensing of Land Surfaces, Bonn University, and Dr Angelika Humbert from the Institute of Geophysics, Münster University, who have been investigating the dynamics of Wilkins Ice Shelf for months, this break-up has not yet finished.

"The remaining plate has an arched fracture at its narrowest position, making it very likely that the connection will break completely in the coming days," Braun and Humbert said.


That's worrisome and a bit curious. What's the mechanism that is causing the ice shelf to crumble during the lowest temperatures of the year? Now, admittedly, the Antarctic Peninsula has experienced some of the greatest warming of anywhere on the planet, 2.5 C/4.5 deg F. Even so, the temperature at this time of year is still fscking cold.

Now, it might be that the ice no longer stretches as far north as in the past due to the increased temperatures and that it no longer protects the inner most ice shelves from being disrupting, but that is just a WAG.

Update: Real Climate and Universe Today have more information.

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