Sunday 19 April 2009

The Warming of the Coldest Continent


A little over 12 months ago, scientists examining satellite images of the Antarctic Peninsula observed the disintegration of the Wilkins Ice Shelf (around 71 degrees S; 73 degrees W).

Covering around 13,000 square kilometres Wilkins effectively broke up into innumerable pieces between February and March 2008. With the onset of colder temperatures, sea ice formed between the fragments, securing them through the remainder of the year, behind a relatively thin barrier of unbroken ice some 40 kilometres long. When summer returned the sea ice melted and on April 5 2009 the barrier gave way, enabling the fragmented shelf to move away.

With the dramatic release of pressure, massive crevasses have now appeared in what remains of the inshore segment of the shelf, and further disintegration is anticipated.

NASA and National Oceanic and Atmospheric Administration (NOAA) scientists are in little doubt that the breakup is a direct result of climate change and global warming. The Antarctic Peninsula has experienced some of the earth's most dramatic and consistent rises in temperature over the past 50 years. Scientists have paid particular attention to ice shelves on the Peninsula since the dramatic collapse of the Larsen B ice shelf, further to the north and on the eastern side, in 2002. Prior to the Wilkins collapse scientists noted the formation of large melt-water pools on the surface of the shelf similar to those that preceded the Larsen B event.

Wilkins is the seventh Antarctic Peninsula ice shelf to have collapsed over recent years, accompanied by an overall shrinking of other coastal ice.



AWCS

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