Overview
Antarctica is Earth's southernmost continent. It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean.
At 14,200,000 square kilometers (5,500,000 square miles), it is the fifth-largest continent and nearly twice the size of Australia. About 98% of Antarctica is covered by ice that averages 1.9 km (1.2 mi; 6,200 ft) in thickness, which extends to all but the northernmost reaches of the Antarctic Peninsula.
Geography & Geology
The Ice Sheet
Antarctica is the highest, driest, coldest, and windiest continent. It holds approximately 70% of the world's fresh water and 90% of the world's ice. If all of this ice melted, global sea levels would rise by about 60 meters (200 ft).
Topography
The Transantarctic Mountains divide the continent into two main parts:
- East Antarctica: Composed largely of a high, ice-covered plateau.
- West Antarctica: An archipelago of volcanic islands covered by an ice sheet.
The highest peak is Vinson Massif at 4,892 meters (16,050 ft), located in the Ellsworth Mountains.
Volcanoes
Antarctica has many volcanoes, and several are active. Mount Erebus, located on Ross Island, is the southernmost active volcano on Earth and is known for its persistent lava lake.
Climate
Antarctica is classified as a polar desert. It is the coldest place on Earth. The lowest naturally occurring land temperature ever recorded on Earth was −89.2 °C (−128.6 °F) at the Soviet Vostok Station in 1983.
Precipitation is very low, averaging only 166 mm (6.5 in) per year. However, because the snow rarely melts, it accumulates over centuries to form massive ice sheets. Katabatic winds, caused by cold air rushing down steep slopes, can reach speeds of over 300 km/h (180 mph).
Biodiversity
Few terrestrial vertebrates live in Antarctica, and those that do are limited to the sub-Antarctic islands. Flora is limited to lichens, mosses, and two species of flowering plants: the Antarctic hair grass and Antarctic pearlwort.
The surrounding waters, however, are teeming with life:
- Penguins: Including Emperor, Adélie, Gentoo, and Chinstrap species.
- Marine Mammals: Blue whales, killer whales (Orcas), and various seal species like the Weddell and Leopard seals.
- Antarctic Krill: A small crustacean that is the keystone species of the Antarctic ecosystem.
Political Status & Research
Antarctica has no government and no indigenous population. It is governed by the Antarctic Treaty System, signed in 1959 by 12 nations. Today, over 50 nations have signed the treaty.
The treaty prohibits military activity, mineral mining, and nuclear disposal. It supports scientific research and protects the continent's eco-zone. During the summer, about 5,000 people reside at various research stations, a number that drops to around 1,000 in the winter.