Map of Antarctica

Although Antarctica began icing about 45.5 million years ago, scientists have only been able to extract samples dating 800,000 years old. The terrain below Antarctica's ice sheet is mountainous – it has the highest average elevation of any continent in the world at 2,500 meters.

The Transantarctic Mountains, one of the longest mountain ranges on Earth, bisects Antarctica. Some of its peaks have elevations higher than 4,500 meters above sea level and are ice-free. The Ellsworth Mountains to the west of the Transantarctic range include Mount Vinson, the highest point on the continent at 4,900 meters.

Volcanoes, likely due to the West Antarctic Rift System, exist under Antarctica's ice sheet. These volcanoes, including Mount Erebus, exist where the Antarctic tectonic plate is thinning. This resembles the tectonic activity we saw along the East African Rift. See Figure 10.13 to study the locations of these features.