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125-769: Victoria Land is a region in eastern Antarctica which fronts the western side of the Ross Sea and the Ross Ice Shelf , extending southward from about 70°30'S to 78°00'S , and westward from the Ross Sea to the edge of the Antarctic Plateau . It was discovered by Captain James Clark Ross in January 1841 and named after Queen Victoria . The rocky promontory of Minna Bluff is often regarded as

250-668: A model organism . This is by far the best-known sea urchin of the region, but not the only species. Among others, the Southern Ocean is also home to the genus Abatus that burrow through the sediment eating the nutrients they find in it. Several species of brittle stars and sea stars live in Antarctic waters, including the ecologically important Odontaster validus and the long-armed Labidiaster annulatus . Two species of salps are common in Antarctic waters, Salpa thompsoni and Ihlea racovitzai . Salpa thompsoni

375-410: 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 by a Norwegian team in 1895. In the early 20th century, there were a few expeditions into the interior of the continent. British explorers Robert Falcon Scott and Ernest Shackleton were

500-527: A few blue-ice areas , the wind and sublimation remove more snow than is accumulated by precipitation. In the dry valleys, the same effect occurs over a rock base, leading to a barren and desiccated landscape. Antarctica is colder than the Arctic region, as much of Antarctica is over 3,000 m (9,800 ft) above sea level, where air temperatures are colder. The relative warmth of the Arctic Ocean

625-525: A foothold in the area, threatening the native wildlife. A history of overfishing and hunting has left many species with greatly reduced numbers. Pollution, habitat destruction , and climate change pose great risks to the environment. The Antarctic Treaty System is a global treaty designed to preserve Antarctica as a place of research, and measures from this system are used to regulate human activity in Antarctica. Around 98% of continental Antarctica

750-425: A foothold on the islands, some quite successfully. Some plant communities exist around fumaroles , vents emitting steam and gas that can reach 60 °C (140 °F) at around 10 centimetres (3.9 in) below the surface. This produces a warmer environment with liquid water due to melting snow and ice. The active volcano Mount Erebus and the dormant Mount Melbourne , both in the continent's interior, each host

875-740: A fumarole. Two fumaroles also exist on the subantarctic islands, one caused by a dormant volcano on Deception Island in the South Shetland Islands and one on the South Sandwich Islands . The fumarole on Deception Island also supports moss species found nowhere else in Antarctica. The bryophytes of Antarctica consist of 100 species of mosses , and about 25 species of liverworts . While not being as widespread as lichens, they remain ubiquitous wherever plants can grow, with Ceratodon purpureus being found as far south as 84°30' on Mount Kyffin . Unlike most bryophytes,

1000-487: A majority of Antarctic bryophytes do not enter a diploid sporophyte stage, instead they reproduce asexually or have sex organs on their gametophyte stage. Only 30% of bryophytes on the Peninsular and subantarctic islands have a sporophyte stage, and only 25% of those on the rest of the mainland produce sporophytes. The Mount Melbourne fumarole supports the only Antarctic population of Campylopus pyriformis , which

1125-525: A mild climate. West Antarctica was partially in the Northern Hemisphere , and during the time, large amounts of sandstones , limestones , and shales were deposited. East Antarctica was at the equator, where seafloor invertebrates and trilobites flourished in the tropical seas. By the start of the Devonian period (416  Ma ), Gondwana was in more southern latitudes, and the climate

1250-457: A native bacterial community within the subterranean water body of Lake Vostok . The existence of life there is thought to strengthen the argument for the possibility of life on Jupiter 's moon Europa , which may have water beneath its water-ice crust. There exists a community of extremophile bacteria in the highly alkaline waters of Lake Untersee . The prevalence of highly resilient creatures in such inhospitable areas could further bolster

1375-701: A number of mountain ranges in the region, the most prominent being the Ellsworth Mountains. The presence of the West Antarctic Rift System has resulted in volcanism along the border between West and East Antarctica, as well as the creation of the Transantarctic Mountains. East Antarctica is geologically varied. Its formation began during the Archean Eon (4,000 Ma–2,500 Ma), and stopped during

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1500-510: A part of it". Wildlife of Antarctica There is relatively little diversity in Antarctica compared to much of the rest of the world. Terrestrial life is concentrated in areas near the coast. Flying birds nest on the milder shores of the Peninsula and the subantarctic islands. Eight species of penguins inhabit Antarctica and its offshore islands. They share these areas with seven pinniped species. The Southern Ocean around Antarctica

1625-481: A range of items, from algae to other animals. The amphipods are highly diverse with more than 600 recognized species found south of the Antarctic Convergence and there are indications that many undescribed species remain. Among these are several "giants", such as the iconic epimeriids that are up to 8 cm (3.1 in) long. Crabs have traditionally not been recognized as part of the fauna in

1750-478: A small warming of the water. Although a few specimens of the non-native great spider crab ( Hyas araneus ) were captured at the South Shetland Islands in 1986, there have been no further records from the region. Slow moving sea spiders are common, sometimes growing up to about 35 cm (1 ft) in leg span (another example of Polar gigantism). Roughly 20% of the sea spider species in

1875-477: A year, including rain, and the northern Peninsula is the only area on the mainland where temperatures are expected to go above 0 °C (32 °F) in summer. The subantarctic islands have a milder temperature and more water, and so are more conducive to life. The surface temperature of the Southern Ocean varies very little, ranging from 1 °C (33.8 °F) to 1.8 °C (35.2 °F). During

2000-564: Is endemic to South Georgia and some smaller surrounding islands. Ducks, the South Georgia pintail and Eaton's pintail , inhabit South Georgia, Kerguelen and Crozet . The flightless penguins are almost all located in the Southern Hemisphere (the only exception is the equatorial Galapagos penguin ), with the greatest concentration located on and around Antarctica. Four of the 18 penguin species live and breed on

2125-655: Is 1–3 cm (0.39–1.18 in). From the end of the Neoproterozoic era to the Cretaceous , Antarctica was part of the supercontinent Gondwana . Modern Antarctica was formed as Gondwana gradually broke apart beginning around 183 Ma. For a large proportion of the Phanerozoic , Antarctica had a tropical or temperate climate , and it was covered in forests. During the Cambrian period , Gondwana had

2250-411: Is 6 centimetres (2.4 in) long and weighs over 1 gram (0.035 oz). The swarms that form can stretch for kilometres, with up to 30,000 individuals per 1 cubic metre (35 cu ft), turning the water red. Swarms usually remain in deep water during the day, ascending during the night to feed on plankton . Many larger animals depend on krill for their own survival. During the winter when food

2375-542: Is almost 18,000 km (11,200 mi) long: as of 1983 , of the four coastal types, 44% of the coast is floating ice in the form of an ice shelf , 38% consists of ice walls that rest on rock, 13% is ice streams or the edge of glaciers, and the remaining 5% is exposed rock. The lakes that lie at the base of the continental ice sheet occur mainly in the McMurdo Dry Valleys or various oases . Lake Vostok , discovered beneath Russia's Vostok Station ,

2500-727: Is an active volcano in Victoria Land. Antarctica Antarctica ( / æ n ˈ t ɑːr k t ɪ k ə / ) is Earth 's southernmost and least-populated continent . Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean ), it contains the geographic South Pole . Antarctica is the fifth-largest continent, being about 40% larger than Europe , and has an area of 14,200,000 km (5,500,000 sq mi). Most of Antarctica

2625-427: Is an important habitat for several smaller organisms. Long-term observation of individuals of this locally common glass sponge revealed no growth, leading to suggestions of a huge age, perhaps up to 15,000 years (making it one of the longest-lived organisms ). However, more recent observations have revealed a highly variable growth rate where individuals seemingly could lack any visible growth for decades, but another

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2750-480: Is being revealed by techniques such as remote sensing , ground-penetrating radar , and satellite imagery . Geologically, West Antarctica closely resembles the South American Andes . The Antarctic Peninsula was formed by geologic uplift and the transformation of sea bed sediments into metamorphic rocks . West Antarctica was formed by the merging of several continental plates , which created

2875-449: Is caused by the emission of chlorofluorocarbons and halons into the atmosphere, which causes ozone to break down into other gases. The extreme cold conditions of Antarctica allow polar stratospheric clouds to form. The clouds act as catalysts for chemical reactions, which eventually lead to the destruction of ozone. The 1987 Montreal Protocol has restricted the emissions of ozone-depleting substances. The ozone hole above Antarctica

3000-511: Is common in this habitat. These two similar types of gigantism are believed to be related to the cold water, which can contain high levels of oxygen, combined with the low metabolic rates ("slow life") of animals living in such cold environments. The rocky shores of mainland Antarctica and its offshore islands provide nesting space for over 100 million birds every spring. These nesters include species of albatrosses , petrels , skuas , gulls and terns . The insectivorous South Georgia pipit

3125-581: Is covered by the Antarctic ice sheet , with an average thickness of 1.9 km (1.2 mi). Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation . It is mainly a polar desert , with annual precipitation of over 200 mm (8 in) along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost 60 metres (200 ft). Antarctica holds

3250-426: Is covered in ice up to 4.7 kilometres (2.9 mi) thick. Antarctica's icy deserts have extremely low temperatures, high solar radiation, and extreme dryness. Any precipitation that does fall usually falls as snow, and is restricted to a band around 300 kilometres (186 mi) from the coast. Some areas receive as little as 50 mm (2.0 in) of precipitation annually. The coldest temperature recorded on Earth

3375-600: Is divided into West Antarctica and East Antarctica by the Transantarctic Mountains , which stretch from Victoria Land to the Ross Sea . The vast majority of Antarctica is covered by the Antarctic ice sheet , which averages 1.9 km (1.2 mi) in thickness. The ice sheet extends to all but a few oases , which, with the exception of the McMurdo Dry Valleys, are located in coastal areas. Several Antarctic ice streams flow to one of

3500-470: Is evidence of a large number of volcanoes under the ice, which could pose a risk to the ice sheet if activity levels were to rise. The ice dome known as Dome Argus in East Antarctica is the highest Antarctic ice feature, at 4,091 metres (13,422 ft). It is one of the world's coldest and driest places—temperatures there may reach as low as −90 °C (−130 °F), and the annual precipitation

3625-408: Is expected to add about 11 cm (5 in) to global sea level rise . Marine ice sheet instability may cause West Antarctica to contribute tens of centimeters more if it is triggered before 2100. With higher warming, instability would be much more likely, and could double global, 21st-century sea-level rise. The fresh, 1100-1500 billion tons (GT) per year of meltwater from the ice dilutes

3750-564: Is found in ice-free areas, whereas Ihlea racovitzai is found in the high latitude areas near ice. Due to their low nutritional value, they are normally only eaten by fish, with larger animals such as birds and marine mammals only eating them when other food is scarce. Several species of marine worms are found in the Southern Ocean, including Parborlasia corrugatus and Eulagisca gigantea , which at lengths up to 2 m (6.6 ft) and 20 cm (8 in) respectively are examples of Polar gigantism. Like several other marine species of

3875-497: Is found on the western edge of the Antarctic Peninsula. Coastal algal blooms can cover up to 2 square kilometres (0.77 sq mi) of the peninsula. Well-adapted moss and lichen can be found in rocks throughout the continent. The subantarctic islands are a more favourable environment for plant growth than the mainland. Human activities, especially whaling and sealing , have caused many introduced species to gain

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4000-487: Is home to 10 cetaceans , many of them migratory . There are very few terrestrial invertebrates on the mainland, although the species that do live there have high population densities. High densities of invertebrates also live in the ocean, with Antarctic krill forming dense and widespread swarms during the summer. Benthic animal communities also exist around the continent. Over 1000 fungi species have been found on and around Antarctica. Larger species are restricted to

4125-485: Is hostile to microscopic fungi due to large fluctuations in temperature on the surface of rocks, which range from 2 °C below the air temperature in the winter to 20 °C above air temperature in the summer. However, the more stable nanoenvironments inside the rocks allow microbial populations to develop. Most communities consist of only a few species. The most studied community occurs in sandstone, and different species arrange themselves in bands at different depths from

4250-426: Is lower than in the rest of the world. Individual niches , determined by environmental factors, are filled by very few species. Roughly 1150 fungi species have been identified. Lichens account for 400 of these, while 750 are non-lichenised. Only around 20 species of fungi are macroscopic. The non-lichenised species come from 416 different genera, representing all major fungi phyla. The first fungi identified from

4375-479: Is otherwise found in Europe and South Africa. Subantarctic flora is dominated by the coastal tussock grass , that can grow up to 2 metres (7 ft). Only two flowering plants inhabit continental Antarctica, the Antarctic hair grass ( Deschampsia antarctica ) and the Antarctic pearlwort ( Colobanthus quitensis ). Both are found only on the western edge of the Antarctic Peninsula and on two nearby island groups,

4500-582: Is predicted to slowly disappear; by the 2060s, levels of ozone are expected to have returned to values last recorded in the 1980s. The ozone depletion can cause a cooling of around 6 °C (11 °F) in the stratosphere . The cooling strengthens the polar vortex and so prevents the outflow of the cold air near the South Pole, which in turn cools the continental mass of the East Antarctic ice sheet. The peripheral areas of Antarctica, especially

4625-576: Is scarce, adult Antarctic krill can revert to a smaller juvenile stage, using their own body as nutrition. Many benthic crustaceans have a non-seasonal breeding cycle, and some raise their eggs and young in a brood pouch (they lack a pelagic larvae stage). Glyptonotus antarcticus at up to 20 cm (8 in) in length and 70 grams (2.5 oz) in weight, and Ceratoserolis trilobitoides at up to 8 cm (3.1 in) in length are unusually large benthic isopods and examples of Polar gigantism. Amphipods are abundant in soft sediments, eating

4750-441: Is the largest subglacial lake globally and one of the largest lakes in the world. It was once believed that the lake had been sealed off for millions of years, but scientists now estimate its water is replaced by the slow melting and freezing of ice caps every 13,000 years. During the summer, the ice at the edges of the lakes can melt, and liquid moats temporarily form. Antarctica has both saline and freshwater lakes. Antarctica

4875-469: Is the only truly pelagic fish in the waters near Antarctica. Six pinniped species inhabit Antarctica. The largest, the Southern elephant seal ( Mirounga leonina ), can reach up to 4,000 kilograms (8,818 lb) and over 6 metres (20 ft) long, while females of the smallest, the Antarctic fur seal ( Arctophoca gazella ), reach only 150 kilograms (331 lb). These two species live north of

5000-504: Is transferred through the Arctic sea ice and moderates temperatures in the Arctic region. East Antarctica is colder than its western counterpart because of its higher elevation. Weather fronts rarely penetrate far into the continent, leaving the centre cold and dry, with moderate wind speeds. Heavy snowfalls are common on the coastal portion of Antarctica, where snowfalls of up to 1.22 m (48 in) in 48 hours have been recorded. At

5125-476: The Antarctic Circle (one of the five major circles of latitude that mark maps of the world), Antarctica is surrounded by the Southern Ocean . Rivers exist in Antarctica; the longest is the Onyx . Antarctica covers more than 14.2 million km (5,500,000 sq mi), almost double the area of Australia, making it the fifth-largest continent, and comparable to the surface area of Pluto . Its coastline

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5250-672: The Antarctic Convergence , almost 90% of the species are endemic to the region. Cod icefish (Nototheniidae), as well as several other families, are part of the Notothenioidei suborder, collectively sometimes referred to as icefish. The suborder contains many species with antifreeze proteins in their blood and tissue, allowing them to live in water that is around or slightly below 0 °C (32 °F). Antifreeze proteins are also known from Southern Ocean snailfish and eelpouts. There are two icefish species from

5375-606: The Beardmore Glacier by Frank Wild on the Nimrod Expedition in 1907, and low-grade coal is known to exist across many parts of the Transantarctic Mountains. The Prince Charles Mountains contain deposits of iron ore . There are oil and natural gas fields in the Ross Sea. Antarctica is the coldest, windiest, and driest of Earth's continents. Near the coast, the temperature can exceed 10 °C in summer and fall to below −40 °C in winter. Over

5500-641: The Cretaceous period (146–66 Ma), though southern beech trees ( Nothofagus ) became prominent towards the end of the Cretaceous. Ammonites were common in the seas around Antarctica, and dinosaurs were also present, though only a few Antarctic dinosaur genera ( Cryolophosaurus and Glacialisaurus , from the Early Jurassic Hanson Formation of the Transantarctic Mountains, and Antarctopelta , Trinisaura , Morrosaurus and Imperobator from Late Cretaceous of

5625-492: The Dry Valleys the normally epilithic lichen species ( Acarospora gwynnii , Buellia frigida , B. grisea , B. pallida , Carbonea vorticosa , Lecanora fuscobrunnea , L. cancriformis , and Lecidella siplei ) are found primarily in protected niches beneath the rock surface occupying a cryptoendolithic ecological niche. Lichen species identified in recent research: The greatest plant diversity

5750-683: The Early Triassic . The Antarctic Peninsula began to form during the Jurassic period ( 206 to 146 million years ago ). Africa separated from Antarctica in the Jurassic around 160 Ma, followed by the Indian subcontinent in the early Cretaceous (about 125 Ma). Ginkgo trees, conifers, Bennettitales , horsetails , ferns and cycads were plentiful during the time. In West Antarctica, coniferous forests dominated throughout

5875-462: The Northern Hemisphere , an eventual decline of fisheries in the Southern Ocean and a potential collapse of certain marine ecosystems . While many Antarctic species remain undiscovered, there are documented increases in Antarctic flora , and large fauna such as penguins are already having difficulty retaining suitable habitat. On ice-free land, permafrost thaws release greenhouse gases and formerly frozen pollution. Scientists have studied

6000-399: The cod icefish (Nototheniidae) and eelpouts (Zoarcidae). Together the snailfish, eelpouts and notothenioids (which includes cod icefish and several other families) account for almost 9 ⁄ 10 of the more than 320 described fish species in the Southern Ocean. Tens of undescribed species also occur in the region, especially among the snailfish. If strictly counting fish species of

6125-420: The crust-like lichen Buellia frigida , has been used as a model organism in astrobiology research. The same features can be observed in algae and cyanobacteria , suggesting that they are adaptations to the conditions prevailing in Antarctica. This has led to speculation that life on Mars might have been similar to Antarctic fungi, such as Cryomyces antarcticus and Cryomyces minteri . Some of

6250-535: The ozone layer in the atmosphere above Antarctica since the 1970s. In 1985, British scientists, working on data they had gathered at Halley Research Station on the Brunt Ice Shelf , discovered a large area of low ozone concentration over Antarctica. The 'ozone hole' covers almost the whole continent and was at its largest in September 2006; the longest-lasting event occurred in 2020. The depletion

6375-773: The Antarctic continental shelf and upper slope, there are more than 220 species and notothenioids dominate, both in number of species (more than 100) and biomass (more than 90%). Southern Ocean snailfish and eelpouts are generally found in deep waters, while the icefish also are common in shallower waters. In addition to the relatively species-rich families, the region is home to a few species from other families: hagfish (Myxinidae), lamprey (Petromyzontidae), skates (Rajidae), pearlfish (Carapidae), morid cods (Moridae), eel cods (Muraenolepididae), gadid cods (Gadidae), horsefish (Congiopodidae), Antarctic sculpins (Bathylutichthyidae), triplefins (Tripterygiidae) and southern flounders (Achiropsettidae). Among fish found south of

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6500-525: The Antarctic Circle on 17 January 1773, in December 1773, and again in January 1774. Cook came within about 120 km (75 mi) of the Antarctic coast before retreating in the face of field ice in January 1773. In 1775, he called the existence of a polar continent "probable", and in another copy of his journal he wrote: "[I] firmly believe it and it's more than probable that we have seen

6625-719: The Antarctic Peninsula) have been described. During the early Paleogene , Antarctica remained connected to South America as well as to southeastern Australia. Fauna from the La Meseta Formation in the Antarctic Peninsula, dating to the Eocene , is very similar to equivalent South American faunas; with marsupials , xenarthrans , litoptern , and astrapotherian ungulates , as well as gondwanatheres and possibly meridiolestidans . Marsupials are thought to have dispersed into Australia via Antarctica by

6750-423: The Antarctic Peninsula, are then subjected to higher temperatures, which accelerate the melting of the ice. Models suggest that ozone depletion and the enhanced polar vortex effect may also account for the period of increasing sea ice extent, lasting from when observation started in the late 1970s until 2014. Since then, the coverage of Antarctic sea ice has decreased rapidly. Most species in Antarctica seem to be

6875-529: 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 in Antarctica, around half are marine phytoplankton . Multicoloured snow algae are especially abundant in the coastal regions during the summer. Even sea ice can harbour unique ecological communities, as it expels all salt from

7000-491: The Antarctic mainland, whereas the Patagonian toothfish lives in the relatively warmer subantarctic waters. Toothfish are commercially fished, and illegal overfishing has reduced toothfish populations. Another abundant icefish group is the genus Notothenia , which like the Antarctic toothfish have antifreeze in their bodies. An unusual species of icefish is the Antarctic silverfish ( Pleuragramma antarcticum ), which

7125-554: The Antarctic region, but studies in the last few decades have found a few species (mostly king crabs ) in deep water. This initially led to fears (frequently quoted in the mainstream media) that they were invading from more northern regions because of global warming and possibly could cause serious damage to the native fauna, but more recent studies show they too are native and formerly simply had been overlooked. Nevertheless, many species from these southern oceans are extremely vulnerable to temperature changes, being unable to survive even

7250-628: The British explorer Robert Falcon Scott . Scott's Northern Party expedition was in 1911, making the age of the fruitcake 106 years old. A program manager said it was in “excellent condition." The region includes ranges of the Transantarctic Mountains and the McMurdo Dry Valleys (the highest point being Mount Abbott in the Northern Foothills ), and the flatlands known as the Labyrinth . The 2,700-metre (9,000 ft) Mount Melbourne

7375-674: The Cambrian Period. It is built on a craton of rock, which is the basis of the Precambrian Shield . On top of the base are coal and sandstones, limestones, and shales that were laid down during the Devonian and Jurassic periods to form the Transantarctic Mountains. In coastal areas such as the Shackleton Range and Victoria Land, some faulting has occurred. Coal was first recorded in Antarctica near

7500-587: The South Pole the romanised Greek name polus antarcticus , from which derived the Old French pole antartike (modern pôle antarctique ) attested in 1270, and from there the Middle English pol antartik , found first in a treatise written by the English author Geoffrey Chaucer . Belief by Europeans in the existence of a Terra Australis —a vast continent in the far south of

7625-531: The Weddell seals live the furthest south. There are 10 cetacean species found in the Southern Ocean; six baleen whales , and four toothed whales . The largest of these, the blue whale ( Balaenoptera musculus ), grows to 24 metres (79 ft) long weighing 84 tonnes. Many of these species are migratory , and travel to tropical waters during the Antarctic winter. Orcas , which do not migrate, nonetheless regularly travel to warmer waters, possibly to relieve

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7750-593: The West Antarctic, the ocean has warmed by 1 °C (1.8 °F) since 1955. The warming of the Southern Ocean around Antarctica has caused the weakening or collapse of ice shelves , which float just offshore of glaciers and stabilize them. Many coastal glaciers have been losing mass and retreating, causing net-annual ice loss across Antarctica, although the East Antarctic ice sheet continues to gain ice inland. By 2100, net ice loss from Antarctica

7875-431: The adjacent nearshore islands. Insects endemic to Antarctica include: Springtail species identified in recent research: Mite species identified in recent research: Five species of krill , small free-swimming crustaceans , are found in the Southern Ocean. The Antarctic krill ( Euphausia superba ) is one of the most abundant animal species on earth, with a biomass of around 500 million tonnes. Each individual

8000-634: The argument for extraterrestrial life in cold, methane -rich environments. The first international agreement to protect Antarctica's biodiversity was adopted in 1964. The overfishing of krill (an animal that plays a large role in the Antarctic ecosystem) led officials to enact regulations on fishing. The Convention for the Conservation of Antarctic Marine Living Resources , an international treaty that came into force in 1980, regulates fisheries, aiming to preserve ecological relationships. Despite these regulations, illegal fishing —particularly of

8125-416: The biodiversity in Antarctica is still at risk from human activities. Specially protected areas cover less than 2% of the area and provide better protection for animals with popular appeal than for less visible animals. There are more terrestrial protected areas than marine protected areas . Ecosystems are impacted by local and global threats, notably pollution , the invasion of non-native species , and

8250-584: The climate cooled, though flora remained. After deglaciation during the latter half of the Early Permian , the land became dominated by glossopterids (an extinct group of seed plants with no close living relatives), most prominently Glossopteris , a tree interpreted as growing in waterlogged soils, which formed extensive coal deposits. Other plants found in Antarctica during the Permian include Cordaitales , sphenopsids , ferns, and lycophytes . At

8375-527: The colonial authorities in Sydney officially renamed the continent of New Holland to Australia, leaving the term "Terra Australis" unavailable as a reference to Antarctica. Over the following decades, geographers used phrases such as "the Antarctic Continent". They searched for a more poetic replacement, suggesting names such as Ultima and Antipodea . Antarctica was adopted in the 1890s, with

8500-510: The continent as a World Park . The Southern Ocean Whale Sanctuary was established in 1994 by the International Whaling Commission . It covers 50 million km (19 million sq mi) and completely surrounds the Antarctic continent. All commercial whaling is banned in the zone, though Japan has continued to hunt whales in the area, ostensibly for research purposes. Despite these protections,

8625-599: The continent's edge, strong katabatic winds off of the polar plateau often blow at storm force . During the summer, more solar radiation reaches the surface at the South Pole than at the equator because of the 24 hours of sunlight received there each day. Climate change caused by greenhouse gas emissions from human activities occurs everywhere on Earth, and while Antarctica is less vulnerable to it than any other continent, climate change in Antarctica has been observed. Since 1959, there has been an average temperature increase of >0.05 °C/decade since 1957 across

8750-496: The continent, although it had been uneven. West Antarctica warmed by over 0.1 °C/decade from the 1950s to the 2000s, and the exposed Antarctic Peninsula has warmed by 3 °C (5.4 °F) since the mid-20th century. The colder, stabler East Antarctica had been experiencing cooling until the 2000s. Around Antarctica, the Southern Ocean has absorbed more oceanic heat than any other ocean, and has seen strong warming at depths below 2,000 m (6,600 ft). Around

8875-402: The creation of small yet permanent polar ice caps. As CO 2 levels declined further the ice began to spread rapidly, replacing the forests that until then had covered Antarctica. Tundra ecosystems continued to exist on Antarctica until around 14-10 million years ago, when further cooling lead to their extermination. The geology of Antarctica, largely obscured by the continental ice sheet,

9000-549: The descendants of species that lived there millions of years ago. As such, they must have survived multiple glacial cycles . The species survived the periods of extremely cold climate in isolated warmer areas , such as those with geothermal heat or areas that remained ice-free throughout the colder climate. Invertebrate life of Antarctica includes species of microscopic mites such as Alaskozetes antarcticus , lice , nematodes , tardigrades , rotifers , krill and springtails . The few terrestrial invertebrates are limited to

9125-582: The early Eocene. Around 53 Ma, Australia- New Guinea separated from Antarctica, opening the Tasmanian Passage . The Drake Passage opened between Antarctica and South America around 30 Ma, resulting in the creation of the Antarctic Circumpolar Current that completely isolated the continent. Models of Antarctic geography suggest that this current, as well as a feedback loop caused by lowering CO 2 levels, caused

9250-766: The elements with a thin layer of snow, which they can often absorb water vapour from. Macrolichens (e.g., Usnea sphacelata , U. antarctica , Umbilicaria decussate , and U. aprina ) and communities of weakly or non-nitrophilous lichens (e.g., Pseudephebe minuscula , Rhizocarpon superficial , and R. geographicum , and several species of Acarospora and Buellia ) are relatively widespread in coastal ice-free areas. Sites with substrates influenced by seabirds are colonized by well-developed communities of nitrophilous lichen species such as Caloplaca athallina , C. citrina , Candelariella flava , Lecanora expectans , Physcia caesia , Rhizoplaca melanophthalma , Xanthoria elegans , and X. mawsonii . In

9375-489: The elevated inland, it can rise to about −30 °C in summer but fall below −80 °C in winter. The lowest natural air temperature ever recorded on Earth was −89.2 °C (−128.6 °F) at the Russian Vostok Station in Antarctica on 21 July 1983. A lower air temperature of −94.7 °C (−138.5 °F) was recorded in 2010 by satellite—however, it may have been influenced by ground temperatures and

9500-553: The end of that period. During the colder Neogene (17–2.5 Ma), a tundra ecosystem replaced the rainforests. The climate of present-day Antarctica does not allow extensive vegetation to form. A combination of freezing temperatures, poor soil quality , and a lack of moisture and sunlight inhibit plant growth, causing low species diversity and limited distribution. The flora largely consists of bryophytes (25 species of liverworts and 100 species of mosses ). There are three species of flowering plants , all of which are found in

9625-587: The end of the Permian, the climate became drier and hotter over much of Gondwana, and the glossopterid forest ecosystems collapsed, as part of the End-Permian mass extinction . There is no evidence of any tetrapods having lived in Antarctica during the Paleozoic. The continued warming dried out much of Gondwana. During the Triassic, Antarctica was dominated by seed ferns (pteridosperms) belonging to

9750-454: The first to reach the magnetic South Pole in 1909, and the geographic South Pole was first reached in 1911 by Norwegian explorer Roald Amundsen . Antarctica is governed by about 30 countries , all of which are parties of the 1959 Antarctic Treaty System . According to the terms of the treaty, military activity, mining, nuclear explosions , and nuclear waste disposal are all prohibited in Antarctica. Tourism , fishing and research are

9875-473: The first use of the name being attributed to the Scottish cartographer John George Bartholomew . Antarctica has also been known by the moniker Great White South , after which British photographer Herbert Ponting named one of his books on Antarctic photography, possibly as a counterpart to the epithet Great White North for Canada . Positioned asymmetrically around the South Pole and largely south of

10000-402: The gap of 12,000 km (7,456 mi). Large animals such as some cetaceans and birds make the round trip annually. Smaller forms of life, such as sea cucumbers and free-swimming snails , are also found in both polar oceans. Factors that may aid in their distribution include temperature differences between the deep ocean at the poles and the equator of no more than 5 °C (9 °F) and

10125-502: The genus Dicroidium , which grew as trees. Other associated Triassic flora included ginkgophytes , cycadophytes , conifers , and sphenopsids. Tetrapods first appeared in Antarctica during the early Triassic , with the earliest known fossils found in the Fremouw Formation of the Transantarctic Mountains. Synapsids (also known as "mammal-like reptiles") included species such as Lystrosaurus , and were common during

10250-503: The genus Dissostichus , the Antarctic toothfish ( D. mawsoni ) and the Patagonian toothfish ( D. eleginoides ), which by far are the largest fish in the Southern Ocean. These two species live on the seafloor from relatively shallow water to depths of 3,000 m (9,800 ft), and can grow to around 2 m (6.6 ft) long weighing up to 100 kg (220 lb), living up to 45 years. The Antarctic toothfish lives close to

10375-525: The globe to balance the northern lands of Europe, Asia, and North Africa—had existed as an intellectual concept since classical antiquity . The belief in such a land lasted until the European discovery of Australia . During the early 19th century, explorer Matthew Flinders doubted the existence of a detached continent south of Australia (then called New Holland ) and thus advocated for the "Terra Australis" name to be used for Australia instead. In 1824,

10500-582: The highly prized Patagonian toothfish which is marketed as Chilean sea bass in the U.S.—remains a problem. In analogy to the 1980 treaty on sustainable fishing , countries led by New Zealand and the United States negotiated a treaty on mining. This Convention on the Regulation of Antarctic Mineral Resource Activities was adopted in 1988. After a strong campaign from environmental organisations, first Australia and then France decided not to ratify

10625-553: The islands of the Kerguelen Plateau , the earliest of which formed around 40 Ma . 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 and erupts around 10 times each day. Ash from eruptions has been found 300 kilometres (190 mi) from the volcanic crater . There

10750-491: The largest of which is the colossal squid ( Mesonychoteuthis hamiltoni ), which at up to 14 metres (46 ft) is among the largest invertebrates in the world. Squid make up most of the diet of some animals, such as grey-headed albatrosses and sperm whales , and the warty squid ( Moroteuthis ingens ) is one of the subantarctic's most preyed upon species by vertebrates. The red Antarctic sea urchin ( Sterechinus neumayeri ) has been used in several studies and has become

10875-540: The least diverse fauna in the world. Terrestrial vertebrates are limited to subantarctic islands, and even then they are limited in number. Antarctica, including the subantarctic islands, has no natural fully terrestrial mammals, reptiles, or amphibians. Human activity has however led to the introduction in some areas of foreign species , such as rats, mice, chickens, rabbits, cats, pigs, sheep, cattle, reindeer , and various fish. Invertebrates, such as beetle species, have also been introduced. The benthic communities of

11000-467: The main human activities in and around Antarctica. During the summer months, about 5,000 people reside at research stations , a figure that drops to around 1,000 in the winter. Despite the continent's remoteness, human activity has a significant effect on it via 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 , and

11125-421: The mainland and its close offshore islands. Another four species live on the subantarctic islands. Emperor penguins have four overlapping layers of feathers, keeping them warm. They are the only Antarctic animal to breed during the winter. Compared to other major oceans, there are few fish species in few families in the Southern Ocean. The most species-rich family are the snailfish (Liparidae), followed by

11250-502: The mainland. With sizes ranging from 2–6 mm (0.08–0.24 in), it is the mainland's largest terrestrial animal. Many terrestrial earthworms and molluscs, along with micro-invertebrates, such as nematodes , tardigrades , and rotifers , are also found. Earthworms, along with insects, are important decomposers . The springtail Gomphiocephalus hodgsoni is endemic and restricted to southern Victoria Land between Mt. George Murray (75°55′S) and Minna Bluff (78°28′S) and to

11375-814: The major current systems or marine conveyor belts which are able to transport eggs and larva . About 1,150 species of fungi have been recorded in the Antarctic region, of which about 750 are non- lichen -forming. Some of the species, having evolved under extreme conditions, have colonised structural cavities within porous rocks and have contributed to shaping the rock formations of the McMurdo Dry Valleys and surrounding mountain ridges. The simplified morphology of such fungi, along with their similar biological structures , metabolism systems capable of remaining active at very low temperatures, and reduced life cycles, make them well suited to such environments. Their thick-walled and strongly melanised cells make them resistant to UV radiation. An Antarctic endemic species,

11500-671: The many Antarctic ice shelves , a process described by ice-sheet dynamics . East Antarctica comprises Coats Land , Queen Maud Land , Enderby Land , Mac . Robertson Land , Wilkes Land , and Victoria Land. All but a small portion of the region lies within the Eastern Hemisphere . East Antarctica is largely covered by the East Antarctic Ice Sheet . There are numerous islands surrounding Antarctica, most of which are volcanic and very young by geological standards. The most prominent exceptions to this are

11625-399: The most species rich insect groups on the islands. Insects play an important role in recycling dead plant material. The mainland of Antarctica has no macro-arthropods. Micro-arthropods are restricted to areas with vegetation and nutrients provided by the presence of vertebrates, and where liquid water can be found. Belgica antarctica , a wingless midge , is the only true insect found on

11750-587: The north'). Antarcticus is derived from the Greek ἀντι- ('anti-') and ἀρκτικός ('of the Bear ', 'northern'). The Greek philosopher Aristotle wrote in Meteorology about an "Antarctic region" in c.  350 BCE . The Greek geographer Marinus of Tyre reportedly used the name in his world map from the second century CE, now lost. The Roman authors Gaius Julius Hyginus and Apuleius used for

11875-578: The ocean around Antarctica, including some that normally reside in the Arctic. The emperor penguin is the only penguin that breeds during the winter in Antarctica; 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. The research found that more than 235 marine organisms live in both polar regions, having bridged

12000-672: The one they are associated with elsewhere, such as infecting a different type of host. Less than 2-3% of species are thought to be endemic . Many species are shared with areas of the Arctic. Most fungi are thought to have arrived in Antarctica via airborne currents or birds. The genus Thelebolus for example, arrived on birds some times ago, but have since evolved local strains. Of the non-lichenised species of fungi and closer relatives of fungi discovered, 63% are ascomycota , 23% are basidiomycota , 5% are zygomycota , and 3% are chytridiomycota . The myxomycota and oomycota make up 1% each, although they are not true fungi. The desert surface

12125-424: The record for the lowest measured temperature on Earth , −89.2 °C (−128.6 °F). The coastal regions can reach temperatures over 10 °C (50 °F) in the summer. Native species of animals include mites , nematodes , penguins , seals and tardigrades . Where vegetation occurs, it is mostly in the form of lichen or moss . The ice shelves of Antarctica were probably first seen in 1820, during

12250-425: The region, Antarctic sponges are long-lived. They are sensitive to environmental changes due to the specificity of the symbiotic microbial communities within them. As a result, they function as indicators of environmental health. The largest is the whitish or dull yellowish Anoxycalyx joubini , sometimes called the giant volcano sponge in reference to its shape. It can reach a height of 2 m (6.5 ft) and

12375-460: The rock surface. Microscopic fungi, especially yeasts , have been found in all Antarctic environments. Antarctica has around 400 lichen species, plants and fungi living symbiotically. They are highly adapted, and can be divided into three main types; crustose lichens, forming thin crusts on the surface, foliose lichens, forming leaf-like lobes, and fruticose lichens , which grow like shrubs. Species are generally divided between those found on

12500-469: The saline Antarctic bottom water , weakening the lower cell of the Southern Ocean overturning circulation (SOOC). According to some research, a full collapse of the SOOC may occur a between 1.7 °C (3.1 °F) and 3 °C (5.4 °F) of global warming, although the full effects are expected to occur over multiple centuries; these include less precipitation in the Southern Hemisphere but more in

12625-480: 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. The name given to the continent originates from the word antarctic , which comes from Middle French antartique or antarctique ('opposite to the Arctic ') and, in turn, the Latin antarcticus ('opposite to

12750-531: The sea ice, and breed in harems on beaches. The other four species can live on the sea ice. Crabeater seals ( Lobodon carcinophagus ) and Weddell seals ( Leptonychotes weddellii ) form breeding colonies, whereas leopard seals ( Hydrurga leptonyx ) and Ross seals ( Ommatophoca rossii ) live solitary lives. Although these species hunt underwater, they breed on land or ice and spend a great deal of time there, as they have no terrestrial predators. The four species that inhabit sea ice are thought to make up 50% of

12875-423: The seafloor are diverse and dense, with up to 155,000 animals found in 1 square metre (10.8 sq ft). As the seafloor environment is very similar all around the Antarctic, hundreds of species can be found all the way around the mainland, which is a uniquely wide distribution for such a large community. Polar and deep-sea gigantism , where invertebrates are considerably larger than their warmer-water relatives,

13000-530: The seafloor is made up of soft sediments, such as sand, mud, and gravel. Ozone depletion and the presence of a seasonal ozone hole above Antarctica exposes the area to high levels of ultraviolet radiation, although the hole is usually largest when snow and ice is more widespread, reducing overall impact. At least 235 marine species are found in both Antarctica and the Arctic, ranging in size from whales and birds to small marine snails, sea cucumbers, and mud-dwelling worms. The large animals often migrate between

13125-724: The southernmost point of Victoria Land, and separates the Scott Coast to the north from the Hillary Coast of the Ross Dependency to the south. Early explorers of Victoria Land include James Clark Ross and Douglas Mawson . In 1979, scientists discovered a group of 309 meteorites in Antarctica, some of which were found near the Allan Hills in Victoria Land. The meteorites appeared to have undergone little change since they were formed at what scientists believe

13250-406: The species of fungi, which are apparently endemic to Antarctica, live in bird dung, and have evolved so they can grow inside extremely cold dung, but can also pass through the intestines of warm-blooded animals. Throughout its history, Antarctica has seen a wide variety of plant life. In the Cretaceous , it was dominated by a fern- conifer ecosystem, which changed into a temperate rainforest by

13375-420: The stress the temperature has on their skin. Most terrestrial invertebrates are restricted to the subantarctic islands. Although there are very few species, those that do inhabit Antarctica have high population densities. In the more extreme areas of the mainland, such as the cold deserts, food webs are sometimes restricted to three nematode species, only one of which is a predator . Many invertebrates on

13500-683: The sub-Antarctic islands. The flightless midge Belgica antarctica , the largest purely terrestrial animal in Antarctica, reaches 6 mm ( 1 ⁄ 4  in) in size. Antarctic krill , which congregates in large schools , is the keystone species of the ecosystem of the Southern Ocean, being an important food organism for whales, seals, leopard seals , fur seals, squid , icefish , and many bird species, such as penguins and albatrosses . Some species of marine animals exist and rely, directly or indirectly, on phytoplankton . Antarctic sea life includes penguins , blue whales , orcas , colossal squids and fur seals . The Antarctic fur seal

13625-413: The subantarctic islands can live in subzero temperatures without freezing, whereas those on the mainland can survive being frozen. Mites and springtails make up most terrestrial arthropod species, although various spiders, beetles, and flies can be found. Several thousand individuals from various mite and springtail species can be found in 1 square metre (10.8 sq ft). Beetles and flies are

13750-400: The subantarctic islands was Peziza kerguelensis , which was described in 1847. In 1898 the first species from the mainland, Sclerotium antarcticum , was sampled. Far more terrestrial species have been identified than marine species. Larger species are restricted to the subantarctic islands and the Antarctic Peninsula. Parasitic species have been found in ecological situations different from

13875-456: The subantarctic islands, and the majority of species discovered have been terrestrial. Plants are similarly restricted mostly to the subantarctic islands, and the western edge of the Peninsula. Some mosses and lichens however can be found even in the dry interior. Many algae are found around Antarctica, especially phytoplankton , which form the basis of many of Antarctica's food webs . Human activity has caused introduced species to gain

14000-422: The subantarctic islands, those found on the Peninsula, those found elsewhere on the mainland, and those with disjointed distribution. The furthest south a lichen has been identified is 86°30'. Growth rates range from 1 centimetre (0.4 in) every 100 years in the more favourable areas to 1 centimetre (0.4 in) every 1000 years in the more inhospitable areas, and usually occurs when the lichen are protected from

14125-479: The summer sea ice covers 4,000,000 square kilometres (1,500,000 sq mi) of ocean. The continental shelf surrounding the mainland is 60 to 240 kilometres (37 to 149 mi) wide. The depth of the seafloor in this area ranges from 50 to 800 metres (164 to 2,625 ft), with an average of 500 metres (1,640 ft). After the shelf, the continental slope descends to abyssal plains at 3,500–5,000 metres (11,483–16,404 ft) deep. In all these areas, 90% of

14250-415: The total biomass of the world's seals. Crabeater seals have a population of around 15 million, making them one of the most numerous large animals on the planet. The New Zealand sea lion ( Phocarctos hookeri ), one of the rarest and most localised pinnipeds, breeds almost exclusively on the subantarctic Auckland Islands , although historically it had a wider range. Out of all permanent mammalian residents,

14375-592: The treaty. Instead, countries adopted the Protocol on Environmental Protection to the Antarctic Treaty (the Madrid Protocol), which entered into force in 1998. The Madrid Protocol bans all mining, designating the continent as a "natural reserve devoted to peace and science". The pressure group Greenpeace established a base on Ross Island from 1987 to 1992 as part of its attempt to establish

14500-543: The two, and smaller animals are expected to be able to spread via underwater currents. However, among smaller marine animals generally assumed to be the same in the Antarctica and the Arctic, more detailed studies of each population have often—but not always—revealed differences, showing that they are closely related cryptic species rather than a single bipolar species. Antarctic animals have adapted to reduce heat loss, with mammals developing warm windproof coats and layers of blubber . Antarctica's cold deserts have some of

14625-470: The various effects of climate change . Early world maps, like the 1513 Piri Reis map , feature the hypothetical continent Terra Australis . Much larger than and unrelated to Antarctica, Terra Australis was a landmass that classical scholars presumed necessary to balance the known lands in the northern hemisphere. Captain James Cook 's ships, HMS  Resolution and Adventure , crossed

14750-412: The water when it freezes, which accumulates into pockets of brine that also harbour dormant microorganisms. When the ice begins to melt, brine pockets expand and can combine to form brine channels, and the algae inside the pockets can reawaken and thrive until the next freeze. Bacteria have also been found as deep as 800 m (0.50 mi) under the ice. It is thought to be likely that there exists

14875-398: The world are from Antarctic waters. They feed on the corals , sponges , and bryozoans that litter the seabed. Many aquatic molluscs are present in Antarctica. Bivalves such as Adamussium colbecki move around on the seafloor, while others such as Laternula elliptica live in burrows filtering the water above. There are around 70 cephalopod species in the Southern Ocean,

15000-529: Was cooler, though fossils of land plants are known from then. Sand and silts were laid down in what is now the Ellsworth, Horlick , and Pensacola Mountains . Antarctica became glaciated during the Late Paleozoic icehouse beginning at the end of the Devonian period (360 Ma), though glaciation would substantially increase during the late Carboniferous . It drifted closer to the South Pole, and

15125-472: Was not recorded at a height of 2 m (7 ft) above the surface as required for official air temperature records. Antarctica is a polar desert with little precipitation ; the continent receives an average equivalent to about 150 mm (6 in) of water per year, mostly in the form of snow. The interior is dryer and receives less than 50 mm (2 in) per year, whereas the coastal regions typically receive more than 200 mm (8 in). In

15250-458: Was observed to increase its size by almost 30% in only two years and one reached a weight of 76 kg (168 lb) in about 20 years or less. Jellyfish are also found there, with 2 examples being the Ross Sea jellyfish and the cobweb jellyfish or giant Antarctic jellyfish . The former is small, at 16 cm (6.3 in) in diameter, while the latter can have 1 metre bell diameter and 5-metre-long tentacles. Fungal diversity in Antarctica

15375-667: Was the birth of the Solar System . In 1981, lichens found at Victoria Land attracted the attention of NASA because lichens may give clues about where to look for the existence of extraterrestrial life . Dr. George Denton, a glaciologist at the University of New Hampshire , looked for microorganisms on Mount Lister , one of the highest in Antarctica; it has the same kind of sandstone in which lichens grow. In 2017, conservationists at Cape Adare , Victoria Land, unearthed an ice-covered fruitcake that they believe once belonged to

15500-503: 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 migrate across the Southern Ocean in search of food. There are approximately 40 bird species that breed on or close to Antarctica, including species of petrels , penguins , cormorants , and gulls . Various other bird species visit

15625-419: Was −89.4 °C (−128.9 °F) at Vostok Station on the Antarctic Plateau . Organisms that survive in Antarctica are often extremophiles . The dry interior of the continent is climatically different from the western Antarctic Peninsula and the subantarctic islands . The Peninsula and the islands are far more habitable; some areas of the peninsula can receive 900 mm (35.4 in) of precipitation

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