large body of floating ice, lying at the head of the Weddell Sea, which is itself an indentation in the Atlantic coastline of Antarctica. It is more than 650 feet (200 m) thick and has an area of 100,400 square miles (260,000 square km). The shelf extends inland on the east side of Berkner Island for more than 250 miles (400 km) to the escarpment of the Pensacola Mountains. The name Filchner was originally applied to the whole shelf, including the larger area west of Berkner Island now called the Ronne Ice Shelf. Because of this, and the fact that the two shelves can be separated only at Berkner Island, the name Filchner-Ronne Ice Shelf is frequently applied to the whole ice mass. The ice shelf, named for the German explorer Wilhelm Filchner, was claimed by the United Kingdom (1908) and by Argentina (1942). Argentina, the United Kingdom, and the United States have operated research stations along its northern edge.