Antarctic Ice Shelf
Antarctic Shelf Ice
Large ice streams drain the interior of the continent and form ice shelves. These ice sheets, which are at least 2 meters above sea level, float over large areas and are fed from the ice, glaciers and/ or ice streams. The two major ice shelves of the earth are in the Antarctic. They are called the Ross ice shelf with 473’000 km2 and the Filchner-Ronne ice shelf with 422’000 km2. Other smaller ice shelves exist and are indicated in the picture below.
Over 40% of the 30000 km long coastline consist of ice shelf. The ice shelf holds the continent together and protects it against the stormy Southern Ocean. A portion of the ice shelf is on water – another part moves on to the land, where it is fixed. At this boundary, there are strong tensions which result in ice fractures.
At the extreme end of the ice shelf, also called the ice barrier, the ice shelf loses contact with the seabed and large tabular icebergs break off into the sea. Sometimes, the ice thickness can reach 200m thick at these shear zone.