Case Study: Animation of Larsen B breakup

When gigantic icebergs break off from Antarctica, the images are dramatic and frequently make the news. The recent collapse of the Larsen B ice shelf in West Antarctica (closest to South America), covered an area larger than the state of Rhode Island and sent thousands of icebergs drifting into the Weddell Sea. This was the largest single event in a series of retreats of the Larsen Ice Shelf in recent years.

Ice inland are thick plates of ice fed by glaciers. The shelves flow over the edge of the continent and float on the ocean around much of Antarctica. The Antarctic Peninsula, where the Larsen shelf is located, has experienced greater warming than other parts of the continent. Over the last five years, the shelf shrunk by about 5700 square kilometers (2200 square miles).

While the Antarctic Peninsula is warming faster than the global average, other parts of this huge continent are cooling, and some of the ice shelves are gaining mass. For example, the Ross Ice Shelf (closest to New Zealand) is thickening as the glacier streams that flow over it slow down. At the same time, this ice shelf has also calved its share of giant icebergs: in March 2000 and again in March and May 2002.