Filchner-Ronne Ice Shelf
The Filchner Ice Shelf was first sighted by the German explorer Wilhelm Filchner in 1912. It lies to the east of Berkner Island. To the west of Berkner Island lies the Ronne Ice Shelf. It was charted from the air by American naval commander Finn Ronne in 1947. Together these two shelves make up the second-largest floating ice shelf by area, and the largest by volume. The bedrock of the ice-covered Berkner Island in fact lies below sea level. Although fed by glaciers from the continental ice cap, and grounded on its landward side, most of the area of the Filchner–Ronne Ice Shelf is floating in the Weddell Sea. The ice shelf itself is up to 3,000 ft (900 m) thick, and the underlying seafloor is up to 4,600 ft (1,400 m) deep.