The Wilkins ice shelf is 5,000 square miles of ice on the western side of the Antarctic Peninsula – an area large than the state of Connecticut. It started in February 2008 (the end of the Antarctic Summer). It continued through the Antarctic winter
which was a big surprise to scientists. That sort of thing had never happened before. Last month the slender remaining ice bridge collapsed and the breakup has accelerated.
This is the tenth ice shelf collapse on the Antarctic Peninsula in two decades. Scientists at the British Antarctic Survey say that this breakup, like the rest is caused by global warming. This collapse however came from melting ice on the bottom of the ice sheet – a foreshadowing of bigger things to come, beginning already on the West Antarctic ice Sheet.
We still have a few ice shelves to go before the West Antarctic gets involved. The Larson C for instance, is larger than Vermont and new Hampshire put together. It is melting from beneath as well. Small changes in ocean temperatures can do a lot of melting because of the great thermal capacity of water.
Current thinking is that the Larson C has maybe 10 years left. The Larson B, the size of Rhode Island, broke up in 2002 in 28 days because surface melt water drained into thousands of crevasses and wedged them apart. The Larson C surface is melting in summer now, that wasn’t happening a decade ago.