Inner forces lead to the splitting up and drifting of the land mass. Around 30 million years ago Antarctica got the shape and locality it has today. Fossils of ferns, fresh-water fish, amphibians and reptiles give evidence that Antarctica has not always been covered by ice. The Mount Vinson Massive in West Antarctica, with its peak 5140 meters above sea level, is the highest mountain in Antarctica. In addition to the nunataks, also larger ice free areas known as oases occur in Antarctica.
Oases form where the ice has withdrawn and where new snow melts faster than it accumulates.
Other areas called Dry Valleys are ice free because of the extremely low precipitation found here. The ice sheet is in constant movement from the central parts of the continent towards the coast. When the ice sheet floats out on the ocean, the so-called ice shelves are created. When ice from the ice shelves breaks off, large tabular ice-bergs are created. These ice bergs can be up towards 5000 km 2 in size.