Composite satellite image of Antarctica (2002)Apollo 4 photograph with Antarctica at top, 1967
Antarctica (/ænˈtɑːrktɪkə/ⓘ)[note 1] isEarth's southernmost and least-populatedcontinent. Situated almost entirely south of theAntarctic Circle and surrounded by theSouthern Ocean (also known as the Antarctic Ocean), it contains the geographicSouth Pole. Antarctica is the fifth-largest continent, being about 40% larger thanEurope, and has an area of 14,200,000 km2 (5,500,000 sq mi). Most of Antarctica is covered by theAntarctic 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 averageelevation. It is mainly apolar desert, with annualprecipitation of over 200 mm (8 in) along thecoast and far less inland. About 70% of the world'sfreshwater reserves are frozen in Antarctica, which, if melted, would raise globalsea levels by almost 60 metres (200 ft). Antarctica holds the record for thelowest measured temperature on Earth, −89.2 °C (−128.6 °F). The coastal regions can reach temperatures over 10 °C (50 °F) in the summer. Nativespecies of animals includemites,nematodes,penguins,seals andtardigrades. Wherevegetation occurs, it is mostly in the form oflichen ormoss.
A speculative representation of Antarctica labelled as 'Terra Australis Incognita' onJan Janssonius'sZeekaart van het Zuidpoolgebied (1657),Het Scheepvaartmuseum
The name given to the continentoriginates from the wordantarctic, which comes fromMiddle Frenchantartique orantarctique ('opposite to theArctic') and, in turn, theLatinantarcticus ('opposite to the north').Antarcticus is derived from theGreekἀντι- ('anti-') andἀρκτικός (arktikos,'of the Bear [Ursa Major], northern').[5] The Greek philosopherAristotle wrote inMeteorology about an "Antarctic region" inc. 350 BCE.[6] The Greek geographerMarinus of Tyre reportedly used the name in his world map from the second century CE, now lost. TheRoman authorsGaius Julius Hyginus andApuleius used for the South Pole theromanised Greek namepolus antarcticus,[7] from which derived theOld Frenchpole antartike (modernpôle antarctique) attested in 1270, and from there theMiddle Englishpol antartik, found first in atreatise written by the English authorGeoffrey Chaucer.[5]
Belief by Europeans in the existence of aTerra Australis—a vast continent in the far south of the globe to balance the northern lands of Europe, Asia, and North Africa—had existed as an intellectual concept sinceclassical antiquity. The belief in such a land lasted until the Europeandiscovery of Australia.[8]
During the early 19th century, explorerMatthew Flinders doubted the existence of a detached continent south of Australia (then calledNew Holland) and thus advocated for the "Terra Australis" name to be used for Australia instead.[9][10] In 1824, the colonial authorities inSydney 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 asUltima andAntipodea.[11]Antarctica was adopted in the 1890s, with the first use of the name being attributed to the ScottishcartographerJohn George Bartholomew.[12]
Antarctica has also been known by the monikerGreat White South, after which British photographerHerbert Ponting named one of his books on Antarctic photography, possibly as a counterpart to the epithetGreat White North forCanada.[13]
Positioned asymmetrically around the South Pole and largely south of theAntarctic Circle (one of the five majorcircles of latitude that mark maps of the world), Antarctica is surrounded by theSouthern Ocean.[note 2]Rivers exist in Antarctica; the longest is theOnyx. Antarctica covers more than 14.2 million km2 (5,500,000 sq mi), almost double the area of Australia, making it the fifth-largest continent, and comparable to the surface area ofPluto. Its coastline is almost 18,000 km (11,200 mi) long:[1] as of 1983[update], of the four coastal types, 44% of the coast is floating ice in the form of anice shelf, 38% consists of ice walls that rest on rock, 13% isice streams or the edge of glaciers, and the remaining 5% is exposed rock.[15]
Thelakes that lie at the base of the continentalice sheet occur mainly in theMcMurdo Dry Valleys or variousoases.[16]Lake Vostok, discovered beneath Russia'sVostok Station, is the largestsubglacial 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.[17] During the summer, the ice at the edges of the lakes can melt, and liquid moats temporarily form. Antarctica has bothsaline and freshwater lakes.[16]
Vinson Massif, in theEllsworth Mountains, is the highest peak in Antarctica at 4,892 m (16,050 ft).[26] Mount Erebus onRoss Island is the world's southernmost activevolcano anderupts around 10 times each day. Ash from eruptions has been found 300 kilometres (190 mi) from thevolcanic crater.[27] There 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.[28] The ice dome known asDome 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 is 1–3 cm (0.39–1.18 in).[29]
Glossopteris sp. leaf from the Permian of Antarctica
During theCambrian period, Gondwana had a mild climate.[33] West Antarctica was partially in theNorthern Hemisphere, and during the time, large amounts ofsandstones,limestones, andshales were deposited. East Antarctica was at theequator, where seafloorinvertebrates andtrilobites flourished in the tropical seas. By the start of theDevonian period (416 Ma), Gondwana was in more southern latitudes, and the climate was cooler, though fossils of land plants are known from then. Sand andsilts were laid down in what is now the Ellsworth,Horlick, andPensacola Mountains.
Antarctica became glaciated during theLate Paleozoic icehouse beginning at the end of the Devonian period (360 Ma), though glaciation would substantially increase during the lateCarboniferous. It drifted closer to the South Pole, and the climate cooled, thoughflora remained.[34] After deglaciation during the latter half of the EarlyPermian, the land became dominated byglossopterids (an extinct group of seed plants with no close living relatives), most prominentlyGlossopteris, a tree interpreted as growing in waterlogged soils, which formed extensivecoal deposits. Other plants found in Antarctica during the Permian includeCordaitales,sphenopsids, ferns, andlycophytes.[35] At the end of the Permian, the climate became drier and hotter over much of Gondwana, and theglossopterid forest ecosystems collapsed, as part of theEnd-Permian mass extinction.[35][36] There is no evidence of anytetrapods having lived in Antarctica during the Paleozoic.[37]
TheAntarctic Peninsula began to form during theJurassic period (206 to 146 million years ago).[40] Africa separated from Antarctica in the Jurassic around 160 Ma, followed by theIndian subcontinent in the early Cretaceous (about 125 Ma).[41]Ginkgo trees, conifers,Bennettitales,horsetails, ferns and cycads were plentiful during the time.[42] About 80 million years ago, flowering plants became the most diverse groups of plants on the continent.[43] In West Antarctica, coniferous forests dominated throughout theCretaceous period (146–66 Ma), though southern beech trees (Nothofagus) became prominent towards the end of the Cretaceous.[44][45]Ammonites were common in the seas around Antarctica, and dinosaurs were also present, though only a few Antarctic dinosaurgenera (Cryolophosaurus andGlacialisaurus, from the Early JurassicHanson Formation of the Transantarctic Mountains,[46] andAntarctopelta,Trinisaura,Morrosaurus andImperobator from Late Cretaceous of the Antarctic Peninsula) have been described.[47][48][49][50]
The flora and fauna of Antarctica before the present was similar to the one from Southern America today, as well as Australia and New Zealand, which it spread to via Antarctica.
Around 53 Ma, Australia-New Guinea separated from Antarctica, opening theTasmanian Passage.[54] TheDrake Passage opened between Antarctica and South America around 30 Ma, resulting in the creation of theAntarctic Circumpolar Current that completely isolated the continent.[55] Models of Antarctic geography suggest that this current, as well as afeedback loop caused by loweringCO2 levels, caused the creation of small yet permanent polar ice caps. As CO2 levels declined further the ice began to spread rapidly, replacing the forests that until then had covered Antarctica.[56]Tundra ecosystems continued to exist on Antarctica until around 14–10 million years ago, when further cooling lead to their extermination.[57]
West Antarctica was formed by the merging of severalcontinental plates, which created a number of mountain ranges in the region, the most prominent being the Ellsworth Mountains. The presence of theWest Antarctic Rift System has resulted involcanism along the border between West and East Antarctica, as well as the creation of the Transantarctic Mountains.[62]
East Antarctica is geologically varied. Its formation began during theArchean Eon (4,000 Ma–2,500 Ma), and stopped during the Cambrian Period.[63] It is built on acraton of rock, which is the basis of the PrecambrianShield.[64] 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.[65] In coastal areas such as theShackleton Range and Victoria Land, somefaulting has occurred.[66][67]
Antarctica is the coldest, windiest, and driest of Earth's continents.[1]Near the coast, the temperature can exceed 10 °C in summer and fall to below −40 °C in winter. Over 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.[71] 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 was not recorded at a height of 2 m (7 ft) above the surface as required for official air temperature records.[72][73]
Antarctica is apolar desert with littleprecipitation; 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).[74] In a fewblue-ice areas, the wind andsublimation remove more snow than is accumulated by precipitation.[75] In the dry valleys, the same effect occurs over a rock base, leading to a barren anddesiccated landscape.[76] Antarctica is colder than theArctic 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 theArctic Ocean is transferred through theArctic sea ice and moderates temperatures in the Arctic region.[77]
Regional differences
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 the continent's edge, strongkatabatic winds off thepolar plateau often blow atstorm force. During the summer, moresolar radiation reaches the surface at the South Pole than at theequator because of the 24 hours of sunlight received there each day.[1]
Climate change
Antarctica's average ice mass change since 2002 has been on the order of 100 billion metric tons per year.[78]
Antarctic surface ice layer temperature trends between 1981 and 2007, based on thermalinfrared observations made by a series ofNOAA satellite sensors.
Climate change caused bygreenhouse gas emissions from human activities occurs everywhere on Earth. While Antarctica is less vulnerable to it than any other continent,[79] it has still been observed there. Since 1957, the average temperature across the continent has risen by more than 0.05°C per decade, though the warming has not been uniform.[80]West Antarctica warmed by over 0.1 °C per decade from the 1950s to the 2000s, and the exposedAntarctic Peninsula has warmed by 3 °C (5.4 °F) since the mid-20th century.[81] The colder, stablerEast Antarctica had been experiencing cooling until the 2000s.[82][83] Around Antarctica, theSouthern Ocean has absorbed moreoceanic heat than any other ocean,[84] and has seen strong warming at depths below 2,000 m (6,600 ft).[85]: 1230 Around the West Antarctic, the ocean has warmed by 1 °C (1.8 °F) since 1955.[81]
The warming of the Southern Ocean around Antarctica has caused the weakening or collapse ofice shelves, which float just offshore ofglaciers and stabilize them. Many coastal glaciers have been losing mass and retreating, causing net ice loss across Antarctica,[85]: 1264 although theEast Antarctic ice sheet continues to gain ice inland. By 2100, net ice loss from Antarctica is expected to add about 11 cm (5 in) to globalsea-level rise.Marine ice sheet instability may cause West Antarctica to contribute tens of centimeters more if it is triggered before 2100.[85]: 1270 With higher warming, instability would be much more likely, and could double global, 21st-century sea-level rise.[86][87][88]
The freshmeltwater from the ice dilutes the salineAntarctic bottom water,[89][90] weakening the lower cell of theSouthern Ocean overturning circulation (SOOC).[85]: 1240 According to some research, a full collapse of the SOOC may occur at between 1.7 °C (3.1 °F) and 3 °C (5.4 °F) of global warming,[91] although the full effects are expected to occur over multiple centuries; these include less precipitation in theSouthern Hemisphere but more in theNorthern Hemisphere, an eventual decline of fisheries in the Southern Ocean and a potentialcollapse of certainmarine ecosystems.[92] While many Antarctic species remain undiscovered, there are documented increases inAntarctic flora,[93] and largefauna such aspenguins are already having difficulty retaining suitable habitat. On ice-free land,permafrost thaws releasegreenhouse gases and formerly frozen pollution.[94]
The West Antarctic ice sheet is likely to completely melt[95][96] unless temperatures are reduced by 2 °C (3.6 °F) below 2020 levels.[97] The loss of this ice sheet would take between 500 and 13,000 years.[98][99] A sea-level rise of 3.3 m (10 ft 10 in) would occur if the ice sheet collapses, leaving ice caps on the mountains, and 4.3 m (14 ft 1 in) if those ice caps also melt.[100] The far-stabler East Antarctic ice sheet may only cause a sea-level rise of 0.5 m (1 ft 8 in) – 0.9 m (2 ft 11 in) from the current level of warming, a small fraction of the 53.3 m (175 ft) contained in the full ice sheet.[101] With global warming of around 3 °C (5.4 °F), vulnerable areas likeWilkes Basin andAurora Basin may collapse over around 2,000 years,[98][99] potentially adding up to 6.4 m (21 ft 0 in) to sea levels.[102]
Scientists have studied theozone layer in theatmosphere above Antarctica since the 1970s. In 1985, British scientists, working on data they had gathered atHalley Research Station on theBrunt Ice Shelf, discovered a large area of lowozone concentration over Antarctica.[103][104] The 'ozone hole' covers almost the whole continent and was at its largest in September 2006;[105] the longest-lasting event occurred in 2020.[106] The depletion is caused by theemission ofchlorofluorocarbons and halons into the atmosphere, which causes ozone to break down into other gases.[107] The extreme cold conditions of Antarctica allowpolar stratospheric clouds to form. The clouds act ascatalysts for chemical reactions, which eventually lead to the destruction of ozone.[108] The 1987Montreal Protocol has restricted the emissions of ozone-depleting substances. The ozone hole above Antarctica is predicted to slowly disappear; by the 2060s, levels of ozone are expected to have returned to values last recorded in the 1980s.[109]
The ozone depletion can cause a cooling of around 6 °C (11 °F) in thestratosphere. The cooling strengthens thepolar 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 the Antarctic Peninsula, are then subjected to higher temperatures, which accelerate the melting of the ice.[104] 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.[110][111]
Most species in Antarctica seem to be the descendants of species that lived there millions of years ago. As such, they must have survived multipleglacial cycles. The species survived the periods of extremely cold climate inisolated warmer areas, such as those withgeothermal heat or areas that remained ice-free throughout the colder climate.[112]
There are approximately 40 bird species that breed on or close to Antarctica, including species ofpetrels,penguins,cormorants, andgulls. Various other bird species visit the ocean around Antarctica, including some that normally reside in the Arctic.[119] Theemperor penguin is the only penguin that breeds during the winter in Antarctica; it and theAdélie penguin breed farther south than any other penguin.[116]
ACensus of Marine Life by some 500 researchers during theInternational Polar Year was released in 2010. The research found that more than 235 marine organisms live in both polar regions, having bridged the gap of 12,000 km (7,456 mi). Large animals such as somecetaceans and birds make the round trip annually. Smaller forms of life, such assea cucumbers andfree-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 the major current systems or marine conveyor belts which are able to transport eggs andlarva.[120]
About 1,150 species offungi have been recorded in the Antarctic region, of which about 750 are non-lichen-forming.[121][122] Some of the species, having evolved under extreme conditions, havecolonised structural cavities within porous rocks and have contributed to shaping the rock formations of the McMurdo Dry Valleys and surrounding mountain ridges.[123]
The same features can be observed in algae andcyanobacteria, suggesting that they areadaptations to the conditions prevailing in Antarctica. This has led to speculation thatlife on Mars might have been similar to Antarctic fungi, such asCryomyces antarcticus andCryomyces minteri.[123] Some of 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.[125][126]
Deschampsia antarctica atCollins Glacier, Antarctica. This species is one of only two flowering plants native to Antarctica, the other one being Antarctic pearlwort (Colobanthus quitensis).
Throughout its history, Antarctica has seen a wide variety of plant life. In theCretaceous, it was dominated by a fern-conifer ecosystem, which changed into a temperaterainforest by the end of that period. During the colderNeogene (17–2.5 Ma), atundra ecosystem replaced the rainforests. The climate of present-day Antarctica does not allow extensive vegetation to form.[127] A combination of freezing temperatures, poorsoil quality, and a lack of moisture and sunlight inhibit plant growth, causing lowspecies diversity and limited distribution. Theflora largely consists ofbryophytes (25 species ofliverworts and 100 species ofmosses). There are three species offlowering plants, all of which are found in the Antarctic Peninsula:Deschampsia antarctica (Antarctic hair grass),Colobanthus quitensis (Antarctic pearlwort) and the non-nativePoa annua (annual bluegrass).[128]
Other organisms
Of the 700 species of algae in Antarctica, around half are marinephytoplankton. Multicolouredsnow algae are especially abundant in the coastal regions during the summer.[129] Evensea ice can harbour unique ecological communities, as it expels all salt from the water when it freezes, which accumulates into pockets ofbrine that also harbour dormant microorganisms. When the ice begins to melt, brine pockets expand and can combine to form brine channels, and thealgae inside the pockets can reawaken and thrive until the next freeze.[130][131] Bacteria have also been found as deep as 800 m (0.50 mi) under the ice.[132] It is thought to be likely that there exists a native bacterial community within the subterranean water body ofLake Vostok.[133] The existence of life there is thought to strengthen the argument for the possibility of life onJupiter's moonEuropa, which may have water beneath its water-ice crust.[134] There exists a community ofextremophile bacteria in the highlyalkaline waters ofLake Untersee.[135][136] The prevalence of highly resilient creatures in such inhospitable areas could further bolster the argument forextraterrestrial life in cold,methane-rich environments.[137]
Early world maps, like the1513 Piri Reis map, feature the hypothetical continentTerra Australis. Much larger than and unrelated to Antarctica,Terra Australis was a landmass thatclassical scholars presumed necessary to balance the known lands in the northern hemisphere.[146]
Captain James Cook's ships,HMS Resolution andAdventure, crossed the Antarctic Circle on 17 January 1773, in December 1773, and again in January 1774.[147] Cook came within about 120 km (75 mi) of the Antarctic coast before retreating in the face offield ice in January 1773.[148] In 1775, he called the existence of a polar continent "probable", and in another copy of hisjournal he wrote: "[I] firmly believe it and it's more than probable that we have seen a part of it".[149]
Sealers were among the earliest to go closer to the Antarctic landmass, perhaps in the earlier part of the 19th century. The oldest known human remains in the Antarctic region was a skull, dated from 1819 to 1825, that belonged to a young woman onYamana Beach at theSouth Shetland Islands. The woman, who was likely to have been part of asealing expedition, was found in 1985.[150]
The first person to see Antarctica or its ice shelf was long thought to have been the British sailorEdward Bransfield, a captain in theRoyal Navy, who discovered the tip of the Antarctic peninsula on 30 January 1820. However, a captain in theImperial Russian Navy,Fabian Gottlieb von Bellingshausen, recorded seeing an ice shelf on 27 January.[151] The American sealerNathaniel Palmer, whose sealing ship was in the region at this time, may also have been the first to sight the Antarctic Peninsula.[152]
On 22 January 1840, two days after the discovery of the coast west of theBalleny Islands, some members of the crew of the 1837–1840 expedition of the French explorerJules Dumont d'Urville disembarked on theDumoulin Islands, off the coast of Adélie Land, where they took some mineral, algae, and animal samples, erected the French flag, and claimed Frenchsovereignty over the territory.[157] The American captainCharles Wilkes led an expedition in 1838–1839 and was the first to claim he had discovered the continent.[158] The British naval officerJames Clark Ross failed to realise that what he referred to as "the various patches of land recently discovered by the American, French and English navigators on the verge of the Antarctic Circle" were connected to form a single continent.[159][160][161][note 5] The American explorerMercator Cooper landed on East Antarctica on 26 January 1853.[164]
The first confirmed landing on the continental mass of Antarctica occurred in 1895 when the Norwegian-Swedishwhaling shipAntarctic reachedCape Adare.[165]
During theNimrod Expedition led by the British explorerErnest Shackleton in 1907, parties led byEdgeworth David became the first to climbMount Erebus and to reach thesouth magnetic pole.Douglas Mawson, who assumed the leadership of the Magnetic Pole party on their perilous return, retired in 1931.[166] Between December 1908 and February 1909, Shackleton and three members of his expedition became the first humans to traverse theRoss Ice Shelf, the first to cross the Transantarctic Mountains (via the Beardmore Glacier), and the first to set foot on thesouth Polar Plateau. On 14 December 1911,an expedition led by Norwegian explorerRoald Amundsen from the shipFram became the first to reach the geographic South Pole, using a route from theBay of Whales and up theAxel Heiberg Glacier.[167] One month later, the doomedTerra Nova Expedition reached the pole.[168]
The American explorerRichard E. Byrd led four expeditions to Antarctica during the 1920s, 1930s, and 1940s, using the first mechanisedtractors. His expeditions conducted extensive geographical and scientific research, and he is credited with surveying a larger region of the continent than any other explorer.[169] In 1937,Ingrid Christensen became the first woman to step onto the Antarctic mainland.[170]Caroline Mikkelsen had landed on an island of Antarctica, earlier in 1935.[171]
The South Pole was next reached on 31 October 1956, when a U.S. Navy group led by Rear AdmiralGeorge J. Dufek successfully landed an aircraft there.[172] Six women were flown to the South Pole as a publicity stunt in 1969.[173][note 6] In the summer of 1996–1997, Norwegian explorerBørge Ousland became the first person to cross Antarctica alone from coast to coast, helped by a kite on parts of the journey.[174] Ousland holds the record for the fastest unsupported journey to the South Pole, taking 34 days.[175]
The first semi-permanent inhabitants of regions near Antarctica (areas situated south of theAntarctic Convergence) were British and American sealers who used to spend a year or more onSouth Georgia, from 1786 onward. During the whaling era, which lasted until 1966, the population of the island varied from over 1,000 in the summer (over 2,000 in some years) to some 200 in the winter. Most of the whalers were Norwegian, with an increasing proportion from Britain.[176][note 7]
Antarctica's population consists mostly of the staff ofresearch stations in Antarctica (which are continuously maintained despite the population decline in the winter), although there are 2 all-civilian bases in Antarctica: theEsperanza Base and theVilla Las Estrellas base.[177] The number of people conducting and supporting scientific research and other work on the continent and its nearby islands varies from about 1,200 in winter to about 4,800 in the summer, with an additional 136 people in the winter to 266 people in the summer from the 2 civilian bases (as of 2017). Some of theresearch stations are staffed year-round, the winter-over personnel typically arriving from their home countries for a one-year assignment. TheRussian OrthodoxHoly Trinity Church at theBellingshausen Station onKing George Island opened in 2004; it is staffed year-round by one or twopriests, who are similarly rotated every year.[178][179]
The first child born in the southern polar region was a Norwegian girl,Solveig Gunbjørg Jacobsen, born inGrytviken on 8 October 1913.[180]Emilio Marcos Palma was the first person born south of the60th parallel south and the first to be born on the Antarctic mainland at the Esperanza Base of the Argentine Army, on 7 January 1978.[181]
Antarctica's status is regulated by the 1959Antarctic Treaty and other related agreements, collectively called the Antarctic Treaty System. Antarctica is defined as all land and ice shelves south of 60° S for the purposes of the Treaty System.[1] The treaty was signed by twelve countries, including theSoviet Union, the United Kingdom, Argentina,Chile, Australia, and the United States. Since 1959, a further 42 countries haveacceded to the treaty. Countries can participate in decision-making if they can demonstrate that they do significant research on Antarctica; as of 2022[update], 29 countries have this 'consultative status'.[185] Decisions are based onconsensus, instead of avote. The treaty set aside Antarctica as a scientific preserve and established freedom of scientific investigation and environmental protection.[186][187]
In the present, sovereignty over regions of Antarctica is claimed by seven different countries.[1] While a few of these countries have mutually recognised each other's claims,[193] the validity of the claims is not recognised universally.[1] New claims on Antarctica have been suspended since 1959, although in 2015, Norway formally defined Queen Maud Land as including the unclaimed area between it and the South Pole.[194]
The Argentine, British, and Chilean claims overlap and have caused friction. In 2012, after the BritishForeign & Commonwealth Office designated a previously unnamed areaQueen Elizabeth Land in tribute toQueen Elizabeth II'sDiamond Jubilee,[195] the Argentine government protested against the claim.[196] The UK passed some of the areas it claimed to Australia and New Zealand after they achieved independence. The claims by Britain, Australia, New Zealand, France, and Norway do not overlap and are recognised by each other.[193] Other member nations of the Antarctic Treaty do not recognise any claim, yet have shown some form of territorial interest in the past.[197]
Brazil has a designated "zone of interest" that is not considered an actual claim.[198]
Peru formally reserved its right to make a claim.[197]
Russia inherited the Soviet Union's right to claim territory under the original Antarctic Treaty.[199]
South Africa formally reserved its right to make a claim.[197]
The United States reserved its right to make a claim in the original Antarctic Treaty.[199]
Deposits of coal,hydrocarbons, iron ore,platinum,copper,chromium,nickel,gold, and other minerals have been found in Antarctica, but not in large enough quantities to extract.[200] The Protocol on Environmental Protection to the Antarctic Treaty, which came into effect in 1998 and is due to be reviewed in 2048, restricts the exploitation of Antarctic resources, including minerals.[201]
Tourists have beenvisiting Antarctica since 1957.[202] Tourism is subject to the provisions of the Antarctic Treaty and Environmental Protocol;[203] the self-regulatory body for the industry is theInternational Association of Antarctica Tour Operators.[204] Tourists arrive by small or medium ship at specific scenic locations with accessible concentrations of iconic wildlife.[202] Over 74,000 tourists visited the region during the 2019–2020 season, of which 18,500 travelled on cruise ships but did not leave them to explore on land.[205] The numbers of tourists fell rapidly after the start of theCOVID-19 pandemic. Some nature conservation groups have expressed concern over the potential adverse effects caused by the influx of visitors and have called for limits on the size of visitingcruise ships and a tourism quota.[206] The primary response by Antarctic Treaty parties has been to develop guidelines that set landing limits and closed or restricted zones on the more frequently visited sites.[207]
Tourism in Antarctica is, in part, ecologically focused with expeditions being offered for bird watching tours due to the high numbers ofAdélie,King, andGentoo penguins – among other species. One site in particular – McDonald Beach – is known to be a high-traffic area for tourists watching the Adélie penguins who number more than 40,000.[208]
Overland sightseeing flights operated out of Australia and New Zealand until theMount Erebus disaster in 1979, when anAir New Zealand plane crashed into Mount Erebus, killing all of the 257 people on board.Qantas resumed commercial overflights to Antarctica from Australia in the mid-1990s.[209] There are manyairports in Antarctica.
In 2017, there were more than 4,400 scientists undertaking research in Antarctica, a number that fell to just over 1,100 in the winter.[1] There are over 70 permanent and seasonal research stations on the continent; the largest, United States'McMurdo Station, is capable of housing more than 1,000 people.[210][211] TheBritish Antarctic Survey has five major research stations on Antarctica, one of which is completely portable. The BelgianPrincess Elisabeth station is one of the most modern stations and the first to becarbon-neutral.[212] Argentina, Australia, Chile, and Russia also have a large scientific presence on Antarctica.[1]
Geologists primarily studyplate tectonics,meteorites, and the breakup of Gondwana.Glaciologists study the history and dynamics of floating ice,seasonal snow, glaciers, and ice sheets.Biologists, in addition to researching wildlife, are interested in how low temperatures and the presence of humans affect adaptation and survival strategies in organisms.[213]Biomedical scientists have made discoveries concerning the spreading ofviruses and the body's response to extreme seasonal temperatures.[214]
The high elevation of the interior, the low temperatures, and the length of polar nights during the winter months all allow for betterastronomical observations at Antarctica than anywhere else on Earth.
The largestneutrino detector in the world, theIceCube Neutrino Observatory, is at the Amundsen-Scott Station. It consists of around 5,500digital optical modules, some of which reach a depth of 2,450 m (8,040 ft), that are held in 1 km3 (0.24 cu mi) of ice.[217] Scientists also observed higher radiation dose rates around the coast of Antarctica compared with the global average: this is attributed to cosmic rays going through the thinner atmosphere compared to equatorial latitudes.[218]
Antarctica provides a unique environment for the study of meteorites: the dry polar desert preserves them well, and meteorites older than a million years have been found. They are relatively easy to find, as the dark stone meteorites stand out in a landscape of ice and snow, and the flow of ice accumulates them in certain areas.
TheAdelie Land meteorite, discovered in 1912, was the first to be found. Meteorites contain clues about the composition of theSolar System and its early development.[219] Most meteorites come from asteroids, but a few meteorites found in Antarctica came from the Moon and Mars.[220][note 8]
Major scientific organizations in Antarctica have released strategy and action plans focused on advancing national interests and objectives in Antarctica, supporting cutting-edge research to understand the interactions between the Antarctic region and climate systems. TheBritish Antarctic Survey (BAS) released a 10-year (2023–2033) strategy report to reduce greenhouse gas emissions and to focus on creating sustainable living onEarth.[222] Environmental sustainability is named as one of the top focus areas by the BAS strategy, highlighting the main challenge and priority to embed environmental sustainability into everything.[223]
In 2022, theAustralian Antarctic Program (AAP) released a new Strategy and 20-year Action Plan (2022–2036) to modernize its Antarctic program. The global climate system was highlighted as one of the main priorities that will be supported and studied through the AAP Strategy Plan. It emphasizes the importance of understanding the vital role of Antarctica and the Southern Ocean in climate and weather to improve current knowledge and inform management responses.[224]
In 2021, theUnited States Antarctic Program (USAP) released a Midterm Assessment on the 2015 Strategic Vision for Antarctic and Southern Ocean Research, stressing the prominent role of the Southern Ocean in the global carbon cycle and sea level rise.[225] The USAP outlines the Changing Antarctic Ice Sheets Initiative as a top priority to enhance understanding of why ice sheets are changing now, and how they will change in the future.[226]
The Antarctic ice sheet's changing height
Antarctic ice sheets are a central focus of contemporary climate research due to urgent questions about their stability and reaction to global warming.Satellite technology enables researchers to study the ice sheets both through on-site fieldwork andremote sensing, facilitating detailed analyses of ice dynamics to predict future changes in a warming world.
The INStabilities & Thresholds in ANTarctica (INSTANT) Scientific Research Programme proposes three research themes, investigating the complex interactions between theatmosphere,ocean, and solidEarth in Antarctica. Its aims include improving the understanding and predictions of these processes to aid decision makers in risk assessment, management, and mitigation related to Antarctic climate change.
The Australian-led ICECAP project utilized advanced aerogeophysical techniques to map deep subglacial basins andchannels that connect the ice sheet to the ocean.[227] This mapping improves predictions of ice sheet stability, the impacts ofclimate change on the ice sheets, and their potential contributions to globalsea level rise.[227]
Culture
Music and film
The southernmost music festival in the world,Icestock, has been held at McMurdo Station since 1989. The organizers, performers, and attendees of Icestock are all personnel working at McMurdo or nearbyScott Base.[228][229][230] The Antarctic Film Festival is held annually between bases, with 48 stations registered to participate as of 2022. The festival is designed forshort films of 5 minutes or less.[231]
In 2011, Australian classicalharpistAlice Giles became the first professional musician to perform in Antarctica.[232] The first full-length fictional film to be shot in Antarctica wasSouth of Sanity, a 2012 low budget Britishhorror film.[233] An upcoming film directed byNick Cassavetes and starringAnthony Hopkins,Bruno Penguin and the Staten Island Princess, will be the first majorHollywood production to shoot in Antarctica.[234]
There are two principal holidays celebrated across Antarctica:Midwinter Day on the day of the southernwinter solstice (June 20 or 21) andAntarctica Day on December 1, which commemorates the signing of the Antarctic Treaty in 1959.[240][241]
^The word was originally pronounced with the firstc silent in English, but thespelling pronunciation has become common and is often considered more correct. However, the pronunciation with a silentc, and even with the firstt silent as well, is widespread and typical of many similar English words.[2] Thec had ceased to be pronounced inMedieval Latin and was dropped from the spelling inOld French, but it was added back for etymological reasons in English in the 17th century and thereafter began to be pronounced, but (as with other spelling pronunciations) at first only by less educated people.[3] For those who pronounce the firstt, there is also variation between the pronunciationsAnt-ar(c)tica andAn-tar(c)tica.
^Ross passed through what is now known as the Ross Sea and discovered Ross Island (both of which were named after him) in 1841. He sailed along a huge wall of ice that was later named theRoss Ice Shelf.[162]Mount Erebus andMount Terror are named after two ships from his expedition:HMS Erebus andTerror.[163]
^Antarctician meteorites, particularlyALH84001 discovered byANSMET, were at the centre of the controversy about possible evidence oflife on Mars. Because meteorites in space absorb and record cosmic radiation, the time elapsed since the meteorite hit the Earth can be calculated.[221]
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