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 the most southern continent on Earth, and it has the fewest people. It lies almost entirely south of the Antarctic Circle. The continent is surrounded by the Southern Ocean, which is also called the Antarctic Ocean. The geographic South Pole is there. Antarctica is the fifth-largest continent. It is about 40% bigger than Europe. Most of it is covered by a huge layer of ice called the Antarctic ice sheet. The ice is about 1.9 km (1.2 mi) thick on average.

Antarctica is usually the coldest, driest, and windiest continent. It also has the highest average elevation. It is mostly a polar desert. Along the coast, it gets over 200 mm (8 in) of precipitation each year, and much less inland. About 70% of the world's freshwater is frozen there. If all that ice 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 areas can reach over 10 °C (50 °F) in summer. Animals that live there naturally include mites, nematodes, penguins, seals, and tardigrades. Where plants grow, they are 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. In the following decades, 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 travelled 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, and all of them are parties to the 1959 Antarctic Treaty System. Under this treaty, military activity, mining, nuclear explosions, and nuclear waste disposal are not allowed. Tourism, fishing, and research are the main human activities in and around Antarctica. In summer, about 5,000 people live at research stations. In winter, that number drops to around 1,000. Even though the continent is very far away, people still affect it through pollution, ozone depletion, and climate change.

The melting of the West Antarctic ice sheet may be unstable, and this causes the most uncertainty in long-term predictions of sea level rise. This melting also affects the Southern Ocean overturning circulation. Over time, this could have big effects on the climate of the Southern Hemisphere and on life in the Southern Ocean.

Etymology

The name Antarctica comes from the word antarctic. This word came from Middle French antartique or antarctique ("opposite to the Arctic") and the Latin antarcticus ("opposite to the north"). The 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. People thought it might balance the northern lands of Europe, Asia, and North Africa. This idea went back to classical antiquity. The name Terra Australis was used for all the imagined lands that might be where Antarctica is today. This belief lasted until Europeans discovered Australia. In the early 1800s, explorer Matthew Flinders doubted there was a separate continent south of Australia, which was then called New Holland. He suggested using the name Terra Australis for Australia instead. In 1824, colonial authorities in Sydney renamed New Holland as Australia, so Terra Australis could no longer refer to Antarctica. Over the next 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. The Scottish cartographer John George Bartholomew is credited with first using it.

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

Most of Antarctica lies south of the Antarctic Circle, one of five major circles of latitude on maps. The continent is surrounded by the Southern Ocean. Rivers flow here, and the longest is the Onyx. Antarctica covers more than 14.2 million square kilometres (5,500,000 square miles), which is almost twice the size of Australia. It is the fifth-largest continent. Its size can be compared to the surface area of Pluto. Its coastline is almost 18,000 km (11,200 mi) long. As of 1983, about 44% of the coast was floating ice shelf. About 38% was tall ice walls resting on rock. About 13% was ice streams or glacier edges, and 5% was bare rock. Lakes lie under the ice sheet and are found mainly in the McMurdo Dry Valleys or in various oases. Lake Vostok is found beneath Russia's Vostok Station. It is the largest subglacial lake in the world. People once thought it had been sealed off for millions of years. Scientists now think its water is replaced every 13,000 years. Antarctica has both saline lakes and freshwater lakes. The continent is divided into West Antarctica and East Antarctica by the Transantarctic Mountains. These mountains stretch from Victoria Land to the Ross Sea. Most of the continent is covered by the Antarctic ice sheet, which is about 1.9 km (1.2 mi) thick on average. The ice sheet covers all of the oases except a few, which are mostly in coastal areas, and the McMurdo Dry Valleys. Several ice streams flow out to one of the many Antarctic ice shelves. This movement is part of 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. It is mostly covered by the East Antarctic Ice Sheet. Many islands surround Antarctica. Most of them are volcanic and very young by geological standards. The main exceptions are the islands of the Kerguelen Plateau. The oldest of these formed around 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 southernmost active volcano in the world. It erupts about 10 times each day. Its ash has been found 300 kilometres (190 mi) from the volcanic crater. Evidence suggests that many volcanoes lie under the ice. If they became more active, they could be a risk to the ice sheet. The ice dome Dome Argus in East Antarctica is the highest ice feature in Antarctica, at 4,091 metres (13,422 ft). It is one of the coldest and driest places in the world. Temperatures can fall to −90 °C (−130 °F), and only 1–3 cm (0.39–1.18 in) of precipitation falls each year.

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 began to form when 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. It was far to the south for most of the last 400 million years. Plants and animals lived there, including lycopods, Archaeopteris, and glossopterids, which formed coal deposits. Dinosaurs and ammonites lived there too, and ammonites also lived in the nearby seas. Over time, the climate cooled and Antarctica became covered in ice. The 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. It was shaped by several continental plates joining together to form mountains. East Antarctica has more varied 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. It was measured at the Russian Vostok Station in Antarctica on 21 July 1983. Antarctica is a polar desert with very little precipitation, mostly snow. The continent's ice has been slowly shrinking since 2002, and the sea ice around Antarctica 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 found a large area with very little ozone over the continent. They made this discovery using information they had collected 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 that were released into the air. The 1987 Montreal Protocol limited these releases. The ozone hole is expected to slowly get smaller and disappear, with ozone levels returning to what they were in the 1980s by the 2060s.

Biodiversity

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

Most animals and plants in Antarctica are related to species that lived there millions of years ago. They must have survived many glacial cycles, or long periods of extreme cold. They lived through these cold times in isolated warmer areas, such as places with geothermal heat or places that stayed free of ice even when the climate was colder. Animals here include emperor penguins and 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 caught 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 only on land in Antarctica. It grows to 6 mm (1⁄4 in). Antarctic krill gathers in large schools and is a keystone species in the ecosystem of the Southern Ocean. This means many other animals depend on it. These include 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. People are worried that too much fishing could harm the krill. 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 hunted very heavily in the 1700s and 1800s for its pelt. Seal hunters from the United States and the United Kingdom did this. Leopard seals are apex predators in the Antarctic ecosystem. They travel across the Southern Ocean to find food. About 40 bird species nest on or near Antarctica. These include petrels, penguins, cormorants, and gulls. The emperor penguin is the only penguin that breeds in the Antarctic winter. It and the Adélie penguin breed farther south than any other penguin. A Census of Marine Life was carried out by about 500 researchers during the International Polar Year. It was released in 2010. It found that more than 235 sea creatures live in both polar regions, even though the two regions are 12,000 km (7,456 mi) apart. Some cetaceans and birds make the round trip each year. Sea cucumbers and free-swimming snails are also found in both polar oceans. In January 2025, the huge iceberg A-84 broke away from the George VI Ice Shelf. It was about as big as Chicago. This gave researchers a rare chance to explore the seafloor under floating ice shelves using robotic submersibles. They found living places full of large corals, ancient sponges, icefish, giant sea spiders, and even octopuses. These were at depths of up to 1,300 metres (4,300 ft). About 1,150 kinds of fungi have been recorded in the Antarctic region. About 750 of them do not form lichen. 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 keep working at very low temperatures. This helps them survive in this harsh place. Their thick, melanised cells also resist UV radiation from the sun. 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. These may be adaptations to life in Antarctica. This has led scientists to wonder whether life on Mars might be similar to Antarctic fungi such as Cryomyces antarcticus and Cryomyces minteri.

Long ago, Antarctica had many kinds of plants. In the Cretaceous period, it was covered by a fern-conifer ecosystem. By the end of that period, it had become a temperate rainforest. During the colder Neogene period (17 to 2.5 million years ago), a tundra ecosystem replaced the rainforests. Today, freezing temperatures, poor soil quality, and a lack of moisture and sunlight stop most plants from growing. This leads to low species diversity and limited spread. The flora is mostly bryophytes. There are 25 species of liverworts and 100 species of mosses. There are three flowering plants, and all of them are found on the Antarctic Peninsula. They are Deschampsia antarctica (Antarctic hair grass), Colobanthus quitensis (Antarctic pearlwort), and the non-native Poa annua (annual bluegrass). Of the 700 species of algae, about half are marine phytoplankton. Colourful snow algae are especially common along coasts in summer. Sea ice also supports unique communities. When sea ice freezes, it pushes out salt. This forms pockets of brine that hold tiny living things. Bacteria have been found as deep as 800 m (0.50 mi) under the ice. 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. Such tough creatures could suggest that extraterrestrial life might exist in cold places rich in methane. The first international agreement to protect Antarctica's biodiversity was adopted in 1964. Because too much krill fishing threatened the ecosystem, officials made rules for fishing. The Convention for the Conservation of Antarctic Marine Living Resources came into force in 1980. It controls fishing to protect the connections between living things. Even so, illegal fishing of the Patagonian toothfish remains a problem. This fish is sold as Chilean sea bass in the U.S. Following the 1980 treaty on sustainable fishing, countries led by New Zealand and the United States worked on a treaty about mining. The Convention on the Regulation of Antarctic Mineral Resource Activities was adopted in 1988. After a strong campaign by environmental groups, Australia and then France decided not to approve it. Instead, countries adopted the Protocol on Environmental Protection to the Antarctic Treaty, known as the Madrid Protocol. It entered into force in 1998. It bans all mining. It also describes the continent as a "natural reserve devoted to peace and science". The group Greenpeace set up a base on Ross Island from 1987 to 1992. This was part of its effort to make the continent a World Park. The Southern Ocean Whale Sanctuary was set up in 1994 by the International Whaling Commission. It covers 50 million km² (19 million sq mi) and surrounds the continent. Commercial whaling is banned in the zone. However, Japan has continued to hunt whales in the area, saying it is for research. Despite these protections, biodiversity in Antarctica is still at risk. Specially protected areas cover less than 2% of the area. They protect animals with popular appeal better than less well-known animals. There are more land-based 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, such as the 1513 Piri Reis map, showed an imagined continent called Terra Australis. It was much larger than Antarctica and was not really related to it. Early 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. Then he turned 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, wrote that he saw 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 recorded 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. That year, the Norwegian-Swedish whaling ship Antarctic reached Cape Adare.

During the Nimrod Expedition in 1907, the British explorer Ernest Shackleton's team was led by Edgeworth David. They 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 people to step onto the south Polar Plateau. On 14 December 1911, an expedition led by Norwegian explorer Roald Amundsen sailed on the ship Fram. It 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. He used the first machine-powered tractors. In 1937, Ingrid Christensen became the first woman to step onto the Antarctic mainland. The South Pole was reached again on 31 October 1956. 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 people to stay in the lands south of the Antarctic Convergence for a long time were British and American sealers. They lived on South Georgia from 1786 onward. During the whaling era, which lasted until 1966, many workers came to the island in summer. In winter, far fewer people stayed there. Most whalers were Norwegian, and more and more came from Britain. The first child born in the southern polar region was a Norwegian girl, Solveig Gunbjørg Jacobsen. She was born in Grytviken on 8 October 1913. Emilio Marcos Palma was the first person born on the Antarctic mainland. He was born at the Esperanza Base of the Argentine Army on 7 January 1978.

Most people in Antarctica work at research stations. Some of these stations stay open all year, even though fewer people are there in winter. There are also 2 bases that have only civilian workers: the Esperanza Base and the Villa Las Estrellas base. In 2017, about 1,200 people worked on science and other jobs in winter, and about 4,800 in summer. Another 136 to 266 people lived at the 2 civilian bases. Some research stations have staff all year. Winter staff usually come from their home countries for a one-year stay. Christianity is the most common religion, and there are 8 chapels of different Christian groups. Because it is hard to bring religious leaders to the continent, most services are held online. Antarctic English, a special 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. Together, these are called the Antarctic Treaty System. Twelve countries signed the treaty at first, 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 important research in Antarctica can take part in decisions. As of 2022, 29 countries had this 'consultative status.' Decisions are made by consensus, not by vote. The treaty made Antarctica a place for science, where research is free and the environment is protected. Some countries let people 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. It covered lands south of the Strait of Magellan and was given to Pedro Sancho de la Hoz. Spain claimed the land south of the Strait of Magellan all the way to the South Pole. Its borders were set by the Treaty of Tordesillas and Zaragoza. In 1555, this claim was added to Chile. Today, seven countries claim parts of Antarctica. Not every country accepts these claims, and no new claims have been made since 1959. The claims of Argentina, Britain, and Chile overlap, which has caused tension. In 2012, the British Foreign & Commonwealth Office named an area Queen Elizabeth Land to honour Queen Elizabeth II's Diamond Jubilee. Argentina protested. Brazil has a "zone of interest," which 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. There is not enough of them to mine. A set of rules called the Protocol on Environmental Protection to the Antarctic Treaty limits how Antarctic resources, including minerals, can be used. It came into effect in 1998 and will be looked at again in 2048.

Tourists have been visiting Antarctica since 1957. Tourism follows the rules of the Antarctic Treaty and its Environmental Protocol. The International Association of Antarctica Tour Operators helps the industry manage itself. Tourists travel on small or medium ships to see beautiful places and many animals. Much of this tourism is about bird watching, because many penguins live on the continent. McDonald Beach is a busy place where tourists come to watch the Adélie penguin group. 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 in 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 on the number of tourists. Countries that signed the Antarctic Treaty have mainly responded by making guidelines that limit where people can land. They have also closed or restricted the most visited sites.

Main article: Research stations in Antarctica

In 2017, more than 4,400 scientists did research in Antarctica. In winter, this number drops to just over 1,100. There are over 70 research stations on the continent. Some are permanent and some are only used during certain seasons. The largest is the United States' McMurdo Station, which can house more than 1,000 people. The British Antarctic Survey runs 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 how viruses spread. Astrophysicists at the Amundsen–Scott South Pole Station study cosmic microwave background radiation and neutrinos from space. The IceCube Neutrino Observatory, which is 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. Some meteorites older than a million years have been found there. Dark stones are easy to spot against the white ice and snow. Moving ice gathers them in certain areas. The Adelie Land meteorite was found in 1912. It was the first one discovered there. Meteorites help scientists learn about the Solar System and how it formed. Most meteorites come from asteroids, but a few found in Antarctica came from the Moon and Mars.

Culture

The first moving pictures of Antarctica were probably filmed by hand in early 1904 by a member of the Scottish National Antarctic Expedition. In 2004, film critic William Arnold named several well-known Antarctic documentaries. These included 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 film about Shackleton's Antarctic adventure (2000). Some movies were also filmed partly or fully in Antarctica. One example is Mr. Forbush and the Penguins (1971), which starred John Hurt. Another is South of Sanity (2012), a low-budget British horror film. The Winter International Film Festival of Antarctica (WIFFA) began in 2006 to help people feel less alone during the winter. It is held every year for people who spend the winter on the continent. It accepts short films that are 5 minutes or less and were filmed in a 48-hour window.

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