Antarctica

Antarctica 6400px from Blue Marble

1657 map Polus Antarcticus

Antarctica

Mount Vinson from NW at Vinson Plateau by Christian Stangl (flickr)

Glossopteris sp. (fossil leaf) (Permian; Antarctica) 1 (49063572172) (cropped)

Antarctica is Earth's southernmost continent, containing the geographic South Pole. It 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 14.0 million square kilometers (5.4 million square miles), it is the fifth-largest continent. About 98% of Antarctica is covered by ice that averages 1.9 kilometers (1.2 miles) in thickness, which extends to all but the northernmost reaches of the Antarctic Peninsula.

Geography

Antarctica is the coldest, driest, and windiest continent. It has the highest average elevation of all the continents. Antarctica is considered a desert, with annual precipitation of only 200 mm (8 inches) along the coast and far less inland. The temperature in Antarctica has reached −89.2 °C (−128.6 °F). There are no permanent human residents, but anywhere from 1,000 to 5,000 people reside throughout the year at the research stations scattered across the continent. Only cold-adapted plants and animals, including penguins, seals, mosses, lichen, and many types of algae, can survive there.

History

The existence of a southern continent was theorized as far back as the writings of Ptolemy in the 1st century AD, but Antarctica was the last continent discovered and remains largely unexplored. The Russian expedition led by Fabian Gottlieb von Bellingshausen and Mikhail Lazarev on the Vostok and Mirnyy ships discovered the continent in 1820. Various nations have claimed parts of Antarctica as sovereign territory, but the Antarctic Treaty System, established in 1959, has since suspended these claims for peaceful scientific exploration.

Climate

The climate of Antarctica is the coldest on Earth. The continent is also extremely dry (technically a desert), with very little precipitation. The interior of Antarctica is the coldest place on Earth; it recorded the lowest temperature ever, −89.2 °C (−128.6 °F), at the Soviet Union's Vostok Station on July 21, 1983. Coastal regions can be warmer, experiencing milder climates, but temperatures are still far below freezing for most of the year.

Flora and Fauna

Despite the harsh conditions, life persists in Antarctica. The native species of plants are limited to around 350 species of mosses, lichens, and algae. No trees or shrubs are found on the continent. Animal life includes species of penguins, seals, nematodes, tardigrades, and mites. The Southern Ocean surrounding Antarctica is home to many species of whales and fish.

Human Presence

Antarctica has no indigenous inhabitants, and its population consists of temporary residents living at the research stations. The Antarctic Treaty and related agreements, collectively known as the Antarctic Treaty System, regulate international relations with respect to Antarctica, Earth's only continent without a native human population. The treaty, entering into force in 1961, sets aside Antarctica as a scientific preserve, establishes freedom of scientific investigation, and bans military activity on the continent.

Conservation

The unique environment of Antarctica faces threats from climate change, including ice shelf collapse and loss of sea ice. The Antarctic Treaty System also includes measures for environmental protection and conserves living resources in Antarctica.