Antarctica

This article is about the continent. For the region, see Antarctic. For the Chilean commune, see Antártica. For other uses, see Antarctica (disambiguation). "Antipodea" redirects here. For the geographic term, see Antipode.

Antarctica is Earth's southernmost and least-populated continent. It lies almost entirely south of the Antarctic Circle and is surrounded by the Southern Ocean, which is also known as the Antarctic Ocean. The geographic South Pole is found there. Antarctica is the fifth-largest continent, about 40% larger than Europe. Most of it is covered by the Antarctic ice sheet, which is on average 1.9 km (1.2 mi) thick.

Antarctica is, on average, the coldest, driest, and windiest of the continents. It also has the highest average elevation. It is mainly a polar desert, receiving over 200 mm (8 in) of precipitation a year along the coast and far less inland. About 70% of the world's freshwater is frozen there. If it melted, global sea levels would rise by almost 60 metres (200 ft). Antarctica holds the record for the lowest measured temperature on Earth, which is −89.2 °C (−128.6 °F). Coastal regions can reach over 10 °C (50 °F) in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where vegetation occurs, it is mostly lichen or moss.

The ice shelves of Antarctica were probably first seen in 1820, during a Russian expedition led by Fabian Gottlieb von Bellingshausen and Mikhail Lazarev. The decades that followed saw further exploration by French, American, and British expeditions. The first confirmed landing was made by a Norwegian team in 1895. In the early 20th century, a few expeditions went into the interior of the continent. British explorers Douglas Mawson, Edgeworth David, and Alistair Mackay were the first to reach the magnetic South Pole in 1909. The geographic South Pole was first reached in 1911 by Norwegian explorer Roald Amundsen.

Antarctica is governed by 29 countries, all of which are parties to the 1959 Antarctic Treaty System. Under the treaty, military activity, mining, nuclear explosions, and nuclear waste disposal are all prohibited. Tourism, fishing and research are the main human activities in and around Antarctica. In summer, about 5,000 people live at research stations, and this drops to around 1,000 in winter. Even though the continent is so remote, human activity still affects it through pollution, ozone depletion, and climate change.

The melting of the potentially unstable West Antarctic ice sheet causes the most uncertainty in century-scale projections of sea level rise. The same melting also affects the Southern Ocean overturning circulation, which can eventually lead to significant impacts on the Southern Hemisphere climate and Southern Ocean productivity.

Etymology

The name Antarctica comes from the word antarctic, which came from Middle French antartique or antarctique ("opposite to the Arctic") and the Latin antarcticus ("opposite to the north"). That Latin word came from the Greek anti- ("opposite") and arktikos ("of the Bear Ursa Major, northern"). The Greek philosopher Aristotle wrote about an "Antarctic region" in his book Meteorology around 350 BC. The Greek geographer Marinus of Tyre reportedly used the name on his world map in the second century AD. The Roman writers Gaius Julius Hyginus and Apuleius called the South Pole the romanised Greek name polus antarcticus. From this came the Old French pole antartike in 1270, and then the Middle English pol antartik, which was first found in a treatise written by the English author Geoffrey Chaucer.

Europeans had long believed in a large southern land called Terra Australis, which was thought to balance the northern lands of Europe, Asia, and North Africa. This idea had existed since classical antiquity. The name Terra Australis was used for all the imagined lands that might be where Antarctica now is known to be. Belief in such a land lasted until the European discovery of Australia. In the early 1800s, explorer Matthew Flinders doubted there was a separate continent south of Australia, which was then called New Holland, and suggested using the name Terra Australis for Australia instead. In 1824, the colonial authorities in Sydney renamed New Holland as Australia, so Terra Australis could no longer refer to Antarctica. Over the following decades, geographers used phrases like "the Antarctic Continent" and suggested other names, such as Ultima and Antipodea. The name Antarctica was adopted in the 1890s, and the first use of it is credited to the Scottish cartographer John George Bartholomew.

Geography

Main article: Geography of Antarctica

See also: Extreme points of Antarctica, List of mountains in Antarctica, List of ultras of Antarctica, and List of places in Antarctica

Antarctica lies mostly south of the Antarctic Circle, one of five major circles of latitude on maps, and is surrounded by the Southern Ocean. Rivers exist here, and the longest is the Onyx. The continent covers more than 14.2 million km² (5,500,000 sq mi), almost double the area of Australia. It is the fifth-largest continent, and its size is comparable to the surface area of Pluto. Its coastline is almost 18,000 km (11,200 mi) long. As of 1983, 44% of the coast is floating ice shelf, 38% is ice walls resting on rock, 13% is ice streams or glacier edges, and 5% is exposed rock. Lakes at the base of the ice sheet are found mainly in the McMurdo Dry Valleys or various oases. Lake Vostok, found beneath Russia's Vostok Station, is the largest subglacial lake in the world. It was once believed to have been sealed off for millions of years, but scientists now estimate its water is replaced every 13,000 years. Antarctica has both saline and freshwater lakes. The continent is divided into West Antarctica and East Antarctica by the Transantarctic Mountains, which stretch from Victoria Land to the Ross Sea. Most of the continent is covered by the Antarctic ice sheet, which averages 1.9 km (1.2 mi) thick. The ice sheet reaches all but a few oases, which are mostly in coastal areas, apart from the McMurdo Dry Valleys. Several ice streams flow to one of the many Antarctic ice shelves, a process described by ice-sheet dynamics.

East Antarctica includes Coats Land, Queen Maud Land, Enderby Land, Mac. Robertson Land, Wilkes Land, and Victoria Land. Almost all of it lies in the Eastern Hemisphere, and it is largely covered by the East Antarctic Ice Sheet. Many islands surround Antarctica, most of them volcanic and very young by geological standards. The main exceptions are the islands of the Kerguelen Plateau, the earliest of which formed around 40 Ma (40 million years ago). Vinson Massif, in the Ellsworth Mountains, is the highest peak in Antarctica at 4,892 m (16,050 ft). Mount Erebus on Ross Island is the world's southernmost active volcano. It erupts around 10 times each day, and its ash has been found 300 kilometres (190 mi) from the volcanic crater. Evidence suggests many volcanoes lie under the ice, which could be a risk to the ice sheet if they became more active. The ice dome Dome Argus in East Antarctica is the highest Antarctic ice feature, at 4,091 metres (13,422 ft). It is one of the coldest and driest places in the world, where temperatures can fall to −90 °C (−130 °F) and yearly precipitation is only 1–3 cm (0.39–1.18 in).

Geologic history

Main article: Geology of Antarctica

Further information: Geology of the Antarctic Peninsula and List of fossiliferous stratigraphic units in Antarctica

From the end of the Neoproterozoic era to the Cretaceous, Antarctica was part of the supercontinent Gondwana. Modern Antarctica formed as Gondwana slowly broke apart, starting in the Jurassic period. For much of the Phanerozoic, Antarctica had a fairly temperate climate and was covered in forests, even though it was far to the south for most of the last 400 million years. Over time, plants and animals lived there, including lycopods, Archaeopteris, glossopterids that formed coal deposits, dinosaurs, and ammonites in the nearby seas. As the climate cooled, Antarctica became covered in ice. Forests that once covered the land were replaced by spreading ice.

Antarctica is now covered by a large ice sheet, so its rocks are hard to study directly. Scientists use tools such as remote sensing, ground-penetrating radar, and satellite imagery to learn about them. West Antarctica is geologically similar to the Andes in South America, and it was shaped by several continental plates joining together to form mountains. East Antarctica is more varied in its rocks and formed over a very long time. Coal was first recorded in Antarctica near the Beardmore Glacier by Frank Wild on the Nimrod Expedition in 1907. There are also oil and natural gas fields in the Ross Sea.

Climate

Main article: Climate of Antarctica

Antarctica is the coldest, windiest, and driest continent on Earth. Near the coast, summer temperatures can go above 10 °C and winter temperatures can drop below −40 °C. Inland, it is much colder: summer can reach about −30 °C, and winter can fall below −80 °C. The lowest natural air temperature ever recorded on Earth was −89.2 °C, at the Russian Vostok Station in Antarctica on 21 July 1983. Antarctica is a polar desert with little precipitation, mostly snow. Its average ice mass has been changing by about 100 billion metric tons per year since 2002, and the amount of Antarctic sea ice reached a new low in 2023.

Main article: Ozone hole

Scientists have studied the ozone layer in the atmosphere above Antarctica since the 1970s. In 1985, British scientists discovered a large area of low ozone over the continent, using data they had gathered at Halley Research Station on the Brunt Ice Shelf. The "ozone hole" was at its largest in September 2006. The problem is caused by chlorofluorocarbons and halons released into the air. The 1987 Montreal Protocol restricted these emissions, and the ozone hole is predicted to slowly disappear, with ozone levels expected to return to 1980s values by the 2060s.

Biodiversity

See also: Antarctic realm, Antarctic microorganism, and Wildlife of Antarctica

Most species in Antarctica seem to be descendants of species that lived there millions of years ago, so they must have survived many glacial cycles. They lived through the very cold periods in isolated warmer areas, such as places with geothermal heat or places that stayed ice-free even in the colder climate. Animals here include emperor penguins with their young. The seabed at McMurdo Sound is home to Antarctic scallops, Antarctic sea urchins and brittle stars. The Antarctic krill is the main species harvested in the krill fishery. Many tiny creatures live here too, including mites like Alaskozetes antarcticus, lice, fleas (Glaciopsyllus antarcticus), nematodes, tardigrades, rotifers, krill and springtails. The flightless midge Belgica antarctica is the largest animal that lives purely on land in Antarctica, growing to 6 mm (1⁄4 in). Antarctic krill gathers in large schools and is the keystone species of the ecosystem of the Southern Ocean. Many animals eat it, including whales, leopard seals, fur seals, squid, icefish, and birds such as penguins and albatrosses. Krill has been commercially fished since the early 1970s, at about 100,000 tonnes per year, and the effects of fishing and possible overfishing are a growing concern. Some sea animals depend, directly or indirectly, on phytoplankton. Antarctic sea life includes penguins, blue whales, orcas, colossal squids and fur seals. The Antarctic fur seal was very heavily hunted in the 18th and 19th centuries for its pelt by seal hunters from the United States and the United Kingdom. Leopard seals are apex predators in the Antarctic ecosystem and travel across the Southern Ocean to find food. About 40 bird species breed on or near Antarctica, including petrels, penguins, cormorants, and gulls. The emperor penguin is the only penguin that breeds in the Antarctic winter, and it and the Adélie penguin breed farther south than any other penguin. A Census of Marine Life by some 500 researchers during the International Polar Year was released in 2010. It found that more than 235 marine organisms live in both polar regions, across a gap of 12,000 km (7,456 mi). Some cetaceans and birds make the round trip each year, while sea cucumbers and free-swimming snails are also found in both polar oceans. In January 2025, the massive iceberg A-84, comparable in size to Chicago, broke away from the George VI Ice Shelf. This gave researchers a rare chance to explore the seafloor beneath floating ice shelves using robotic submersibles. They found ecosystems rich in large corals, ancient sponges, icefish, giant sea spiders, and even octopuses at depths of up to 1,300 metres (4,300 ft). About 1,150 species of fungi have been recorded in the Antarctic region, about 750 of them non-lichen-forming. Some have colonised structural cavities within porous rocks and helped shape rock formations in the McMurdo Dry Valleys. Their simple morphology, similar biological structures, and metabolism systems that stay active at very low temperatures suit this harsh place, and their thick, melanised cells resist UV radiation. An Antarctic endemic species, the crust-like lichen Buellia frigida, has been used as a model organism in astrobiology research. Algae and cyanobacteria show similar features, which may be adaptations to Antarctic conditions. This has led to speculation that life on Mars might have been similar to Antarctic fungi such as Cryomyces antarcticus and Cryomyces minteri.

Throughout its history, Antarctica has had a wide variety of plant life. In the Cretaceous, it was dominated by a fern-conifer ecosystem, which became a temperate rainforest by the end of that period. During the colder Neogene (17–2.5 Ma), a tundra ecosystem replaced the rainforests. Today, freezing temperatures, poor soil quality, and a lack of moisture and sunlight stop extensive plants from growing, which leads to low species diversity and limited spread. The flora is mostly bryophytes, with 25 species of liverworts and 100 species of mosses. There are three flowering plants, all found in the Antarctic Peninsula: Deschampsia antarctica (Antarctic hair grass), Colobanthus quitensis (Antarctic pearlwort) and the non-native Poa annua (annual bluegrass). Of the 700 species of algae, around half are marine phytoplankton, and colourful snow algae are especially common along coasts in summer. Sea ice also supports unique communities, as it pushes out salt when it freezes, forming pockets of brine that hold tiny living things. Bacteria have been found as deep as 800 m (0.50 mi) under the ice, and a native bacterial community is thought to likely live in the water under Lake Vostok. This supports the idea that life could exist on Jupiter's moon Europa, which may have water beneath its icy crust. Extremophile bacteria live in the very alkaline waters of Lake Untersee, and such tough creatures could support the possibility of extraterrestrial life in cold, methane-rich places. The first international agreement to protect Antarctica's biodiversity was adopted in 1964. Because overfishing of krill threatened the ecosystem, officials made rules for fishing. The Convention for the Conservation of Antarctic Marine Living Resources, which came into force in 1980, regulates fisheries to protect ecological relationships. Even so, illegal fishing of the Patagonian toothfish, sold as Chilean sea bass in the U.S., remains a problem. In line with the 1980 treaty on sustainable fishing, countries led by New Zealand and the United States negotiated a treaty on mining. The Convention on the Regulation of Antarctic Mineral Resource Activities was adopted in 1988, but after a strong campaign from environmental organisations, Australia and then France decided not to ratify it. Instead, countries adopted the Protocol on Environmental Protection to the Antarctic Treaty (the Madrid Protocol), which entered into force in 1998. It bans all mining and designates the continent as a "natural reserve devoted to peace and science". The pressure group Greenpeace set up a base on Ross Island from 1987 to 1992 as part of its attempt to make the continent a World Park. The Southern Ocean Whale Sanctuary was established in 1994 by the International Whaling Commission. It covers 50 million km² (19 million sq mi) and completely surrounds the continent. All commercial whaling is banned in the zone, though Japan has continued to hunt whales in the area, ostensibly for research. Despite these protections, biodiversity in Antarctica is still at risk. Specially protected areas cover less than 2% of the area and protect animals with popular appeal better than less visible animals. There are more terrestrial protected areas than marine protected areas. Ecosystems face threats from pollution, the invasion of non-native species, and the effects of climate change.

Main articles: History of Antarctica, Colonization of Antarctica, and Farthest south

See also: List of Antarctic expeditions, Women in Antarctica, and List of polar explorers

Early world maps, like the 1513 Piri Reis map, showed an imagined continent called Terra Australis. It was much larger than Antarctica and was not related to it. Classical scholars thought it must exist to balance the lands in the northern half of the world. Captain James Cook's ships, HMS Resolution and Adventure, crossed the Antarctic Circle in 1773 and 1774. Cook got within about 120 km (75 mi) of the coast before turning back because of field ice. In his journal, he wrote that a polar continent was "probable". In the 1800s, sealers were among the first to sail close to the Antarctic land. The British sailor Edward Bransfield, a captain in the Royal Navy, was long thought to be the first to see Antarctica, in 1820. However, a captain in the Imperial Russian Navy, Fabian Gottlieb von Bellingshausen, recorded seeing an ice shelf a few days earlier. The American sealer Nathaniel Palmer may also have been the first to see the Antarctic Peninsula. The first documented landing was made by John Davis in 1821, although some historians doubt this. The American captain Charles Wilkes was the first to claim he had discovered the continent. The American explorer Mercator Cooper landed on East Antarctica in 1853. The first confirmed landing on the continent came in 1895, when the Norwegian-Swedish whaling ship Antarctic reached Cape Adare.

During the Nimrod Expedition in 1907, the British explorer Ernest Shackleton's team, led by Edgeworth David, became the first to climb Mount Erebus and to reach the south magnetic pole. Shackleton and three members of his expedition later became the first humans to set foot on the south Polar Plateau. On 14 December 1911, an expedition led by Norwegian explorer Roald Amundsen from the ship Fram became the first to reach the geographic South Pole. One month later, the Terra Nova Expedition reached the pole. The American explorer Richard E. Byrd led four expeditions in the 1920s, 1930s, and 1940s, using the first mechanised tractors. In 1937, Ingrid Christensen became the first woman to step onto the Antarctic mainland. The South Pole was next reached on 31 October 1956, when a U.S. Navy group led by Rear Admiral George J. Dufek landed an aircraft there. In the summer of 1996–1997, Norwegian explorer Børge Ousland became the first person to cross Antarctica alone from coast to coast.

Demographics

Main article: Demographics of Antarctica

See also: Religion in Antarctica

The first semi-permanent inhabitants of regions south of the Antarctic Convergence were British and American sealers, who spent a year or more on South Georgia from 1786 onward. During the whaling era, which lasted until 1966, the island's population changed from over 1,000 in summer (over 2,000 in some years) to about 200 in winter. Most whalers were Norwegian, with an increasing number from Britain. The first child born in the southern polar region was a Norwegian girl, Solveig Gunbjørg Jacobsen, born in Grytviken on 8 October 1913. Emilio Marcos Palma was the first person born on the Antarctic mainland, at the Esperanza Base of the Argentine Army, on 7 January 1978.

Most people in Antarctica work at research stations, which are kept running all year even when the population drops in winter. There are also 2 all-civilian bases: the Esperanza Base and the Villa Las Estrellas base. The number of people doing science and other work on the continent and nearby islands ranges from about 1,200 in winter to about 4,800 in summer, plus 136 to 266 people from the 2 civilian bases (as of 2017). Some research stations are staffed all year, with winter staff usually arriving from their home countries for a one-year assignment. Christianity is the most common religion, with 8 chapels of various Christian denominations. Because it is hard to bring religious leaders to the continent, most services are held online. Antarctic English, a distinct form of the English language, has been found to be spoken by people living on Antarctica and the subantarctic islands.

Politics

Antarctica's status is set by the 1959 Antarctic Treaty and related agreements, which together are called the Antarctic Treaty System. The treaty was signed by twelve countries, including the Soviet Union, the United Kingdom, Argentina, Chile, Australia, and the United States. Since 1959, 42 more countries have acceded to it. Countries that do significant research in Antarctica can take part in decisions, and 29 countries have this 'consultative status' as of 2022. Decisions are made by consensus rather than by vote. The treaty set Antarctica aside as a scientific preserve, with freedom of scientific research and protection of the environment. Some countries let citizens stationed at research stations there vote in their elections.

Territorial claims

Main article: Territorial claims in Antarctica

In 1539, the King of Spain, Charles V, created the Governorate of Terra Australis, which covered lands south of the Strait of Magellan and was given to Pedro Sancho de la Hoz. Spain claimed the territory south of the Strait of Magellan up to the South Pole, and its borders were set by the Treaty of Tordesillas and Zaragoza. In 1555, the claim was added to Chile. Today, seven countries claim parts of Antarctica, but not every country accepts these claims, and new claims have been paused since 1959. The claims of Argentina, Britain, and Chile overlap and have caused tension. In 2012, the British Foreign & Commonwealth Office named an area Queen Elizabeth Land to honour Queen Elizabeth II's Diamond Jubilee, and Argentina protested. Brazil has a "zone of interest" that is not considered a claim.

Date	Claimant	Territory	Claim limits	Map
1840	France	Adélie Land	Originally undefined; later specified to be 142°2′E to 136°11′E
1908	United Kingdom	British Antarctic Territory	80°0′W to 20°0′W 80°0′W to 74°0′W claimed by Chile (1940) 74°0′W to 53°0′W claimed by Chile (1940) and Argentina (1943) 53°0′W to 25°0′W claimed by Argentina (1943)
1923	New Zealand	Ross Dependency	160°0′E to 150°0′W
1931	Norway	Peter I Island
1933	Australia	Australian Antarctic Territory	44°38′E to 136°11′E, and 142°2′E to 160°00′E
1939	Norway	Queen Maud Land	20°00′W to 44°38′E
1940	Chile	Chilean Antarctic Territory	90°0′W to 53°0′W 80°00′W to 74°00′W claimed by the United Kingdom (1908) 74°00′W to 53°00′W claimed by the United Kingdom (1908) and Argentina (1943)
1943	Argentina	Argentine Antarctica	74°0′W to 25°0′W 74°0′W to 53°0′W claimed by the United Kingdom (1908) and Chile (1940) 53°0′W to 25°0′W claimed by the United Kingdom (1908)
–	(Unclaimed territory)	Marie Byrd Land	150°0′W to 90°0′W (except Peter I Island)

Economy and tourism

Main article: Tourism in Antarctica

See also: Telecommunications in Antarctica, Transport in Antarctica, and Crime in Antarctica

Coal, hydrocarbons, iron ore, platinum, copper, chromium, nickel, gold, and other minerals have been found in Antarctica, but not in amounts large enough to mine. The Protocol on Environmental Protection to the Antarctic Treaty, which came into effect in 1998 and is due to be reviewed in 2048, limits the use of Antarctic resources, including minerals.

Tourists have been visiting Antarctica since 1957. Tourism follows the rules of the Antarctic Treaty and its Environmental Protocol. The industry regulates itself through the International Association of Antarctica Tour Operators. Tourists travel by small or medium ships to scenic places where many animals can be seen. Much of this tourism focuses on bird watching, because many penguins live on the continent. McDonald Beach is a busy area for tourists who come to watch the Adélie penguin population there. Sightseeing flights over land ran from Australia and New Zealand until the Mount Erebus disaster in 1979, when an Air New Zealand plane crashed into Mount Erebus. Qantas started commercial flights to Antarctica from Australia again in the mid-1990s.

Over 74,000 tourists visited the region during the 2019–2020 season. About 18,500 of them travelled on cruise ships but did not leave the ships to explore on land. Some nature groups have worried that so many visitors could harm the environment. They have asked for limits on the size of cruise ships and a cap on the number of tourists. Antarctic Treaty countries have mainly responded by creating guidelines that set limits on landings and by closing or restricting the most visited sites.

Main article: Research stations in Antarctica

In 2017, more than 4,400 scientists did research in Antarctica, but this number fell to just over 1,100 in the winter. There are over 70 research stations on the continent, some permanent and some seasonal. The largest, the United States' McMurdo Station, can house more than 1,000 people. The British Antarctic Survey has five major research stations, and one of them can be moved. The Belgian Princess Elisabeth station is one of the most modern and the first to be carbon-neutral. Scientists study many topics. Geologists study plate tectonics and meteorites. Glaciologists study ice, snow, and glaciers. Biologists study wildlife and how living things survive the cold. Biomedical scientists have learned about how viruses spread. Astrophysicists at the Amundsen–Scott South Pole Station study cosmic microwave background radiation and neutrinos from space. The IceCube Neutrino Observatory, the largest neutrino detector in the world, is at this station.

Antarctica is a good place to study meteorites. The dry land keeps them well preserved, and some meteorites older than a million years have been found there. Dark stones are easy to spot against the ice and snow, and moving ice gathers them in certain areas. The Adelie Land meteorite was discovered in 1912 and was the first one found there. Meteorites help scientists learn about the Solar System and how it developed. Most meteorites come from asteroids, but a few found in Antarctica came from the Moon and Mars.

Culture

The first moving pictures of Antarctica are thought to have been hand-cranked by an unknown member of the Scottish National Antarctic Expedition in early 1904. Film critic William Arnold named several notable Antarctic documentaries in 2004, including South (1919), the Oscar-winning With Byrd at the South Pole (1930), 90° South: With Scott to the Antarctic (1933), The Secret Land (1948), and an IMAX production about Shackleton's Antarctic adventure (2000). Some fiction films were also made partly or entirely in Antarctica, such as Mr. Forbush and the Penguins (1971), starring John Hurt, and South of Sanity (2012), a low-budget British horror film. The Winter International Film Festival of Antarctica (WIFFA) was started in 2006 to help fight social isolation and is held every year for people spending the winter on the continent. It accepts short films of 5 minutes or less, shot during a 48-hour window.

The southernmost music festival in the world, Icestock, has been held at McMurdo Station since 1989. Its organizers, performers, and attendees are all staff working at McMurdo or nearby Scott Base. Sporting events on Antarctica include the Antarctic Ice Marathon & 100k ultra race, the Antarctica Marathon, and the Antarctica Cup Yacht Race. Association football has been played since the early twentieth century, with teams from bases or visiting ships. Two main holidays are celebrated across Antarctica: Midwinter Day, on the day of the southern winter solstice (June 20 or 21), and Antarctica Day, on December 1, which marks the signing of the Antarctic Treaty in 1959.