One of the largest glaciers in Antarctica is thinning, according to satellite measurements. The finding spurs concerns that changes in the glacier's ice shelf along the Antarctic coast may increase the amount of ice that drains from the interior of the continent and floats out to sea.
Each year, the 200-kilometer-long, 25-km-wide Pine Island Glacier depletes the West Antarctic Ice Sheet of about 69 cubic kilometers of ice. Eventually the glacier flows into the sea, where it forms a floating ice shelf about 40 km wide, says Andrew Shepherd, a physicist at University College London. When he and his colleagues analyzed satellite measurements taken between 1992 and 1999, they found that large portions of the Pine Island Glacier thin