Pine Island is one of the largest and fastest-moving glaciers in Antarctica. Satellite measurements have shown that the Pine Island Glacier Basin has a greater net contribution of ice to the sea than any other ice drainage basin in the world, and this has increased due to recent acceleration of the ice stream due to thinning of the glacier. As the ice shelf thins, the grounding line retreats and the speed of the glacier increases. As it sits on bedrock below sea level and drains about 10 percent of the West Antarctica ice sheet, scientists are concerned about the impact Pine Island's continued thinning will have on sea level.
Landsat satellite imagery acquired in January 2011 shows a series of splits along the western edge of the glacier. The same area in January 2012 shows a major break which eventually will extend all the way across the glacier and calve a giant iceberg that is expected to cover about 350 square miles (900 square kilometers).
Scientists will use the Landsat imagery to follow the breaking of the glacier and the movement of the icebergs as they drift from the ice shelf.