July 14, 2008—Another collapse of the Antarctic Peninsula's Wilkins Ice Shelf has the mass of floating ice hanging by a thread, as seen in the above satellite images.
Between May 30 and July 9, the European Space Agency's Envisat satellite captured the latest in a series of large-scale Wilkins breakups. The most recent collapse, which caused a loss of some 520 square miles (1,350 square kilometers) of ice, puzzled scientists: It is the first-known collapse to occur in the Southern Hemisphere winter.
The shelf is now stabilized by a thin ice bridge (seen in the center of the images) that anchors it to nearby Charcot Island.
But this link may soon be severed by a new fracture, first seen in a July 8, 2008, image (above).
Scientists fear that if the bridge falls the entire shelf could disintegrate in relatively short order. They also believe warming oceans are rapidly thinning the shelf from underneath.
"Over the past two decades or so we've seen the most pronounced climate change in the Arctic, and the Antarctic has always been viewed as this sleeping giant," said Mark Serreze, a senior scientist at the National Snow and Ice Data Center in Boulder, Colorado.
"What's happening in terms of the Wilkins Ice Shelf is evidence that change is really happening there—and this sleeping giant is starting to stir."