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129-819: The Suvorov Glacier forms in the Wilson Hills and flows east to the Southern Ocean . Mount Steele , Mount Ellery , the Hornblende Bluffs, Heth Ridge and Mount Send are to the west. To the north, near its mouth, it passes Northrup Head, Whited Inlet and Belousov Point on the Anderson Peninsula. 69°54′S 159°45′E  /  69.900°S 159.750°E  / -69.900; 159.750 . Prominent bluffs that rise to 1,050 metres (3,440 ft) high, located 2 nautical miles (3.7 km; 2.3 mi) southeast of Mount Ellery and near

258-463: A Northwest Passage to "the Western and Southern Ocean of America ". Authors using "Southern Ocean" to name the waters encircling the unknown southern polar regions used varying limits. James Cook 's account of his second voyage implies New Caledonia borders it. Peacock's 1795 Geographical Dictionary said it lay "to the southward of America and Africa"; John Payne in 1796 used 40 degrees as

387-658: A captain in the Russian Imperial Navy ; Edward Bransfield , a captain in the Royal Navy ; and Nathaniel Palmer , an American sailor out of Stonington, Connecticut . It is certain that the expedition, led by von Bellingshausen and Lazarev on the ships Vostok and Mirny , reached a point within 32 km (20 mi) from Princess Martha Coast and recorded the sight of an ice shelf at 69°21′28″S 2°14′50″W  /  69.35778°S 2.24722°W  / -69.35778; -2.24722 that became known as

516-406: A depth of 7,434 metres (24,390 ft). The expedition leader and chief submersible pilot Victor Vescovo , has proposed naming this deepest point the "Factorian Deep", based on the name of the crewed submersible DSV Limiting Factor , in which he successfully visited the bottom for the first time on February 3, 2019. By way of his voyages in the 1770s, James Cook proved that waters encompassed

645-527: 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

774-462: A land in 50° S which he called South France, and believed to be the central mass of the southern continent. He was sent out again to complete the exploration of the new land, and found it to be only an inhospitable island which he renamed the Isle of Desolation, but which was ultimately named after him . The obsession of the undiscovered continent culminated in the brain of Alexander Dalrymple ,

903-523: 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, the colonial authorities in Sydney officially renamed the continent of New Holland to Australia, leaving

1032-525: 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

1161-457: 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

1290-528: A note in the publication read: The Antarctic or Southern Ocean has been omitted from this publication as the majority of opinions received since the issue of the 2nd Edition in 1937 are to the effect that there exists no real justification for applying the term Ocean to this body of water, the northern limits of which are difficult to lay down owing to their seasonal change. The limits of the Atlantic, Pacific and Indian Oceans have therefore been extended South to

1419-701: 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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1548-637: 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

1677-655: 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

1806-480: 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

1935-449: 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

2064-470: 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

2193-408: 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

2322-489: 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 , is the largest subglacial lake globally and one of

2451-582: 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

2580-504: 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

2709-542: 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 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

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2838-662: 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

2967-641: 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

3096-683: 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

3225-586: The Fimbul Ice Shelf . On 30 January 1820, Bransfield sighted Trinity Peninsula , the northernmost point of the Antarctic mainland, while Palmer sighted the mainland in the area south of Trinity Peninsula in November 1820. Von Bellingshausen's expedition also discovered Peter I Island and Alexander I Island , the first islands to be discovered south of the circle. In December 1839, as part of

3354-526: 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

3483-662: 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 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

3612-573: 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 the north'). Antarcticus is derived from the Greek ἀντι- ('anti-') and ἀρκτικός ('of

3741-515: 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 is almost 18,000 km (11,200 mi) long: as of 1983 , of the four coastal types, 44% of the coast

3870-627: The Strait of Magellan in 1520, assumed that the islands of Tierra del Fuego to the south were an extension of this unknown southern land. In 1564, Abraham Ortelius published his first map, Typus Orbis Terrarum , an eight-leaved wall map of the world, on which he identified the Regio Patalis with Locach as a northward extension of the Terra Australis , reaching as far as New Guinea . European geographers continued to connect

3999-630: 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 the many Antarctic ice shelves ,

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4128-709: The United States Exploring Expedition of 1838–42 conducted by the United States Navy (sometimes called "the Wilkes Expedition"), an expedition sailed from Sydney, Australia, on the sloops-of-war USS  Vincennes and USS  Peacock , the brig USS  Porpoise , the full-rigged ship Relief , and two schooners Sea Gull and USS  Flying Fish . They sailed into the Antarctic Ocean, as it

4257-499: The United States Geological Survey . Southern Ocean Main five oceans division: Further subdivision: The Southern Ocean , also known as the Antarctic Ocean , comprises the southernmost waters of the world ocean , generally taken to be south of 60° S latitude and encircling Antarctica . With a size of 21,960,000 km (8,480,000 sq mi), it is the second-smallest of

4386-420: 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

4515-535: 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

4644-687: The parallel 60° south latitude was discovered by the Englishman William Smith , who sighted Livingston Island on 19 February 1819. A few months later Smith returned to explore the other islands of the South Shetlands archipelago, landed on King George Island , and claimed the new territories for Britain. In the meantime, the Spanish Navy ship San Telmo sank in September 1819 when trying to cross Cape Horn. Parts of her wreckage were found months later by sealers on

4773-399: The "South Land" – described by a half legendary " sieur de Gonneyville " – resulted in the discovery of Bouvet Island in 54°10′ S, and in the navigation of 48° of longitude of ice-cumbered sea nearly in 55° S in 1730. In 1771, Yves Joseph Kerguelen sailed from France with instructions to proceed south from Mauritius in search of "a very large continent". He lighted upon

4902-608: The 16th and the early part of the 17th centuries. The Spaniard Gabriel de Castilla , who claimed having sighted "snow-covered mountains" beyond the 64° S in 1603, is recognized as the first explorer that discovered the continent of Antarctica, although he was ignored in his time. In 1606, Pedro Fernández de Quirós took possession for the king of Spain all of the lands he had discovered in Australia del Espiritu Santo (the New Hebrides ) and those he would discover "even to

5031-408: 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 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

5160-514: The 2002 edition the limits of oceans explicitly excluded the seas lying within each of them. The Great Australian Bight was unnamed in the 1928 edition, and delineated as shown in the figure above in the 1937 edition. It therefore encompassed former Southern Ocean waters—as designated in 1928—but was technically not inside any of the three adjacent oceans by 1937. In the 2002 draft edition, the IHO have designated "seas" as subdivisions within "oceans", so

5289-580: 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

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5418-481: The Antarctic Circle, or knew it, if they did. In a voyage from 1822 to 1824, James Weddell commanded the 160-ton brig Jane , accompanied by his second ship Beaufoy captained by Matthew Brisbane. Together they sailed to the South Orkneys where sealing proved disappointing. They turned south in the hope of finding a better sealing ground. The season was unusually mild and tranquil, and on 20 February 1823

5547-557: The Antarctic Continent. Hydrographic Offices who issue separate publications dealing with this area are therefore left to decide their own northern limits (Great Britain uses Latitude of 55 South.) Instead, in the IHO 1953 publication, the Atlantic, Indian and Pacific Oceans were extended southward, the Indian and Pacific Oceans (which had not previously touched pre 1953, as per the first and second editions) now abutted at

5676-790: 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

5805-423: 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

5934-529: 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

6063-521: 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 the South Pole the romanised Greek name polus antarcticus , from which derived

6192-454: The Bight would have still been within the Southern Ocean in 1937 if the 2002 convention were in place then. To perform direct comparisons of current and former limits of oceans it is necessary to consider, or at least be aware of, how the 2002 change in IHO terminology for "seas" can affect the comparison. The Southern Ocean did not appear in the 1953 third edition of Limits of Oceans and Seas ,

6321-681: The CIA World Fact Book ) which already adopted the principle that seas are contained within oceans. This difference in practice is markedly seen for the Pacific Ocean in the adjacent figure. Thus, for example, previously the Tasman Sea between Australia and New Zealand was not regarded by the IHO as part of the Pacific, but as of the 2002 draft edition it is. The new delineation of seas as subdivisions of oceans has avoided

6450-674: 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

6579-475: The National Geographic web site have begun to reference the Southern Ocean. A radical shift from past IHO practices (1928–1953) was also seen in the 2002 draft edition when the IHO delineated "seas" as subdivisions within the boundaries of "oceans". While the IHO are often considered the authority for such conventions, the shift brought them into line with the practices of other publications (e.g.

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6708-591: The Pole". Francis Drake , like Spanish explorers before him, had speculated that there might be an open channel south of Tierra del Fuego. When Willem Schouten and Jacob Le Maire discovered the southern extremity of Tierra del Fuego and named it Cape Horn in 1615, they proved that the Tierra del Fuego archipelago was of small extent and not connected to the southern land, as previously thought. Subsequently, in 1642, Abel Tasman showed that even New Holland (Australia)

6837-708: The South Atlantic to the Cape of Good Hope between 55° and 60° . He thereby laid open the way for future Antarctic exploration by exploding the myth of a habitable southern continent. Cook's most southerly discovery of land lay on the temperate side of the 60th parallel , and he convinced himself that if land lay farther south it was practically inaccessible and without economic value. Voyagers rounding Cape Horn frequently met with contrary winds and were driven southward into snowy skies and ice-encumbered seas; but so far as can be ascertained none of them before 1770 reached

6966-420: The Southern Ocean as extending as far north as South America, and confers great significance on the Antarctic Convergence , yet its description of the Indian Ocean contradicts this, describing the Indian Ocean as extending south to Antarctica. Other sources, such as the National Geographic Society , show the Atlantic , Pacific , and Indian oceans as extending to Antarctica on its maps, although articles on

7095-411: The Southern Ocean as lying immediately south of Australia (see § Australian standpoint ). The National Geographic Society recognized the ocean officially in June 2021. Prior to this, it depicted it in a typeface different from the other world oceans; instead, it shows the Pacific, Atlantic, and Indian Oceans extending to Antarctica on both its print and online maps. Map publishers using

7224-508: The Southern Ocean was inspired by a belief in the existence of a Terra Australis – a vast continent in the far south of the globe to "balance" the northern lands of Eurasia and North Africa – which had existed since the times of Ptolemy . The rounding of the Cape of Good Hope in 1487 by Bartolomeu Dias first brought explorers within touch of the Antarctic cold, and proved that there was an ocean separating Africa from any Antarctic land that might exist. Ferdinand Magellan , who passed through

7353-417: The Southern Ocean, in an open boat called James Caird , and then trekked over South Georgia to raise the alarm at the whaling station Grytviken . 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

7482-444: The Southern Ocean. In Australia, cartographical authorities define the Southern Ocean as including the entire body of water between Antarctica and the south coasts of Australia and New Zealand, and up to 60°S elsewhere. Coastal maps of Tasmania and South Australia label the sea areas as Southern Ocean and Cape Leeuwin in Western Australia is described as the point where the Indian and Southern Oceans meet. Exploration of

7611-466: 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

7740-573: 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

7869-416: 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

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7998-460: The brilliant and erratic hydrographer who was nominated by the Royal Society to command the Transit of Venus expedition to Tahiti in 1769. The command of the expedition was given by the admiralty to Captain James Cook . Sailing in 1772 with Resolution , a vessel of 462 tons under his own command and Adventure of 336 tons under Captain Tobias Furneaux , Cook first searched in vain for Bouvet Island , then sailed for 20 degrees of longitude to

8127-405: The circulation substantially slowing or even passing a tipping point and collapsing outright. The latter would have adverse impacts on global weather and the function of marine ecosystems here, unfolding over centuries. The ongoing warming is already changing marine ecosystems here. Borders and names for oceans and seas were internationally agreed when the International Hydrographic Bureau ,

8256-466: 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

8385-670: The coast between Northrup Head and Anderson Peninsula. Mapped by USGS from surveys and United States Navy air photos, 1960-63. Named by US-ACAN for Master Chief Quartermaster Robert J. Whited, United States Navy, Leading Chief for the staff and a member of Operations Division responsible for maintaining and updating charts for Task Force 43 during Operation Deep Freeze 1968 and 1969. 69°48′S 160°13′E  /  69.800°S 160.217°E  / -69.800; 160.217 . Low ice-covered peninsula, 7 nautical miles (13 km; 8.1 mi) long, terminating in Belousov Point. The feature lies between Gillett Ice Shelf and Suvorov Glacier on

8514-419: The coast of Tierra del Fuego with the coast of New Guinea on their globes, and allowing their imaginations to run riot in the vast unknown spaces of the south Atlantic, south Indian and Pacific oceans they sketched the outlines of the Terra Australis Incognita ("Unknown Southern Land"), a vast continent stretching in parts into the tropics. The search for this great south land was a leading motive of explorers in

8643-467: The coastal margin of the Wilson Hills. Mapped by USGS from surveys and United States Navy air photos, 1960-64. Named by US-ACAN for Lieutenant (later Captain) Richard E. Anderson, CEC, United States Navy, base public works officer at McMurdo Sound during Operation Deep Freeze I and II. He wintered over in the McMurdo area during the latter operation, 1957. [REDACTED]  This article incorporates public domain material from websites or documents of

8772-423: 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,

8901-599: 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

9030-408: 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 the same melting also affects the Southern Ocean overturning circulation , which can eventually lead to significant impacts on

9159-496: 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

9288-402: 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,

9417-597: The debate after the full importance of Southern Ocean overturning circulation had been ascertained, and the term Southern Ocean now defines the body of water which lies south of the northern limit of that circulation. The Southern Ocean overturning circulation is important because it makes up the second half of the global thermohaline circulation , after the better known Atlantic meridional overturning circulation (AMOC). Much like AMOC, it has also been substantially affected by climate change , in ways that have increased ocean stratification , and which may also result in

9546-549: 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

9675-433: The discovery of which he had received news at Cape Town , but from the rough determination of his longitude by Kerguelen, Cook reached the assigned latitude 10° too far east and did not see it. He turned south again and was stopped by ice in 61° 52′ S by 95° E and continued eastward nearly on the parallel of 60° S to 147° E . On 16 March, the approaching winter drove him northward for rest to New Zealand and

9804-582: 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

9933-489: 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

10062-553: 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

10191-642: 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

10320-566: The expedition regained Tahiti for refreshment. In November 1774, Cook started from New Zealand and crossed the South Pacific without sighting land between 53° and 57° S to Tierra del Fuego; then, passing Cape Horn on 29 December, he rediscovered Roché Island renaming it Isle of Georgia , and discovered the South Sandwich Islands (named Sandwich Land by him), the only ice-clad land he had seen, before crossing

10449-534: The five principal oceanic divisions, smaller than the Pacific , Atlantic and Indian oceans, and larger than the Arctic Ocean . The maximum depth of the Southern Ocean, using the definition that it lies south of 60th parallel, was surveyed by the Five Deeps Expedition in early February 2019. The expedition's multibeam sonar team identified the deepest point at 60° 28' 46"S, 025° 32' 32"W, with

10578-402: 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

10707-502: 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

10836-462: The head of Suvorov Glacier, in Wilson Hills. So named by the northern party of New Zealand Geological Survey Antarctic Expedition (NZGSAE), 1963-64, who found the rock here contains the mineral hornblende. 69°58′S 159°45′E  /  69.967°S 159.750°E  / -69.967; 159.750 . A ridge 3 nautical miles (5.6 km; 3.5 mi) long, located 4 nautical miles (7.4 km; 4.6 mi) south of Hornblende Bluffs and near

10965-478: The head of Suvorov Glacier, in the Wilson Hills. Mapped by United States Geological Survey (USGS) from surveys and United States Navy air photos, 1960-63. Named by United States Advisory Committee on Antarctic Names (US-ACAN) for Samuel R. Heth, United States Antarctic Research Program (USARP) biologist at Hallett Station , 1968-69. 69°52′S 160°09′E  /  69.867°S 160.150°E  / -69.867; 160.150 . An ice-covered headland on

11094-501: 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 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

11223-582: 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

11352-518: The island in 1775. Edmond Halley 's voyage in HMS ; Paramour for magnetic investigations in the South Atlantic met the pack ice in 52° S in January 1700, but that latitude (he reached 140 mi [230 km] off the north coast of South Georgia ) was his farthest south. A determined effort on the part of the French naval officer Jean-Baptiste Charles Bouvet de Lozier to discover

11481-553: 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

11610-447: 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 is divided into West Antarctica and East Antarctica by

11739-814: 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,

11868-489: The meridian of South East Cape , and the southern limits of the Great Australian Bight and the Tasman Sea were moved northward. The IHO readdressed the question of the Southern Ocean in a survey in 2000. Of its 68 member nations, 28 responded, and all responding members except Argentina agreed to redefine the ocean, reflecting the importance placed by oceanographers on ocean currents . The proposal for

11997-471: 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 the Antarctic Circle (one of the five major circles of latitude that mark maps of the world), Antarctica is surrounded by

12126-620: The name Southern Ocean won 18 votes, beating the alternative Antarctic Ocean . Half of the votes supported a definition of the ocean's northern limit at the 60th parallel south —with no land interruptions at this latitude—with the other 14 votes cast for other definitions, mostly the 50th parallel south , but a few for as far north as the 35th parallel south . Notably the Southern Ocean Observing System collates data from latitudes higher than 40 degrees south. A draft fourth edition of Limits of Oceans and Seas

12255-525: The need to interrupt the northern boundary of the Southern Ocean where intersected by Drake Passage which includes all of the waters from South America to the Antarctic coast, nor interrupt it for the Scotia Sea , which also extends below the 60th parallel south. The new delineation of seas has also meant that the long-time named seas around Antarctica, excluded from the 1953 edition (the 1953 map did not even extend that far south), are automatically part of

12384-469: The north coast of Livingston Island ( South Shetlands ). It is unknown if some survivor managed to be the first to set foot on these Antarctic islands. The first confirmed sighting of mainland Antarctica cannot be accurately attributed to one single person. It can be narrowed down to three individuals. According to various sources, three men all sighted the ice shelf or the continent within days or months of each other: Fabian Gottlieb von Bellingshausen ,

12513-527: The north side of Suvorov Glacier. The headland, a coastal extension of the Wilson Hills, stands 3.5 nautical miles (6.5 km; 4.0 mi) west-southwest of Belousov Point. Mapped by USGS from surveys and United States Navy air photos, 1960-63. Named by US-ACAN for David A. Northrup, ATN2, United States Navy, Aviation Electronics Technician with Squadron VX-6 at McMurdo Station, 1967. 69°50′S 160°08′E  /  69.833°S 160.133°E  / -69.833; 160.133 . An ice-filled inlet along

12642-434: The northern limit; the 1827 Edinburgh Gazetteer used 50 degrees. The Family Magazine in 1835 divided the "Great Southern Ocean" into the "Southern Ocean" and the "Antarctick [ sic ] Ocean" along the Antarctic Circle, with the northern limit of the Southern Ocean being lines joining Cape Horn, the Cape of Good Hope, Van Diemen's Land and the south of New Zealand. The United Kingdom's South Australia Act 1834 described

12771-586: The ocean and its definition as the waters south of the 60th parallel south in its 2000 revisions, but this has not been formally adopted, due to continuing impasses about some of the content, such as the naming dispute over the Sea of Japan . The 2000 IHO definition was circulated as a draft edition in 2002, and is used by some within the IHO and other organizations, such as the CIA World Factbook and Merriam-Webster . The Australian Government regards

12900-578: 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

13029-622: The ocean's northern limit ceased to abut land masses. In the second edition, the Southern Ocean then extended from Antarctica northward to latitude 40°S between Cape Agulhas in Africa (long. 20°E) and Cape Leeuwin in Western Australia (long. 115°E), and extended to latitude 55°S between Auckland Island of New Zealand (165 or 166°E east) and Cape Horn in South America (67°W). As is discussed in more detail below, prior to

13158-496: The other new sea names within the "Southern Ocean", such as the " Cosmonauts Sea ") and Merriam-Webster , scientists and nations – and even by some within the IHO. Some nations' hydrographic offices have defined their own boundaries; the United Kingdom used the 55th parallel south for example. Other organisations favour more northerly limits for the Southern Ocean. For example, Encyclopædia Britannica describes

13287-511: The precursor to the IHO, convened the First International Conference on 24 July 1919. The IHO then published these in its Limits of Oceans and Seas , the first edition being 1928. Since the first edition, the limits of the Southern Ocean have moved progressively southward; since 1953, it has been omitted from the official publication and left to local hydrographic offices to determine their own limits. The IHO included

13416-469: 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

13545-552: The south, and South America, Africa, Australia, and Broughton Island, New Zealand to the north. The detailed land-limits used were from Cape Horn in Chile eastward to Cape Agulhas in Africa, then further eastward to the southern coast of mainland Australia to Cape Leeuwin , Western Australia . From Cape Leeuwin, the limit then followed eastward along the coast of mainland Australia to Cape Otway , Victoria , then southward across Bass Strait to Cape Wickham , King Island , along

13674-508: The southern latitudes of the globe. Yet, geographers have often disagreed on whether the Southern Ocean should be defined as a body of water bound by the seasonally fluctuating Antarctic Convergence - an oceanic zone where cold, northward flowing waters from the Antarctic mix with warmer Subantarctic waters, or not defined at all, with its waters instead treated as the southern limits of the Pacific, Atlantic, and Indian oceans. The International Hydrographic Organization (IHO) finally settled

13803-406: 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

13932-683: 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

14061-474: 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 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

14190-491: 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 the first use of the name being attributed to the Scottish cartographer John George Bartholomew . Antarctica has also been known by

14319-581: The term Southern Ocean on their maps include Hema Maps and GeoNova. "Southern Ocean" is an obsolete name for the Pacific Ocean or South Pacific, coined by the Spanish explorer Vasco Núñez de Balboa , the first European to discover the Pacific, who approached it from the north in Panama . The "South Seas" is a less archaic synonym. A 1745 British Act of Parliament established a prize for discovering

14448-592: 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

14577-524: The tropical islands of the Pacific. In November 1773, Cook left New Zealand, having parted company with the Adventure , and reached 60° S by 177° W , whence he sailed eastward keeping as far south as the floating ice allowed. The Antarctic Circle was crossed on 20 December and Cook remained south of it for three days, compelled after reaching 67° 31′ S to stand north again in 135° W . A long detour to 47° 50′ S served to show that there

14706-512: The two ships reached latitude 74°15' S and longitude 34°16'45″ W the southernmost position any ship had ever reached up to that time. A few icebergs were sighted but there was still no sight of land, leading Weddell to theorize that the sea continued as far as the South Pole. Another two days' sailing would have brought him to Coat's Land (to the east of the Weddell Sea ) but Weddell decided to turn back. The first land south of

14835-470: 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

14964-412: 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

15093-524: The waters forming the southern limit of the new province of South Australia as "the Southern Ocean". The Colony of Victoria 's Legislative Council Act 1881 delimited part of the division of Bairnsdale as "along the New South Wales boundary to the Southern ocean". In the 1928 first edition of Limits of Oceans and Seas , the Southern Ocean was delineated by land-based limits: Antarctica to

15222-567: The west coast of King Island, then the remainder of the way south across Bass Strait to Cape Grim , Tasmania . The limit then followed the west coast of Tasmania southward to the South East Cape and then went eastward to Broughton Island, New Zealand, before returning to Cape Horn. The northern limits of the Southern Ocean were moved southward in the IHO's 1937 second edition of the Limits of Oceans and Seas . From this edition, much of

15351-449: The westward in latitude 58° S , and then 30° eastward for the most part south of 60° S , a lower southern latitude than had ever been voluntarily entered before by any vessel. On 17 January 1773 the Antarctic Circle was crossed for the first time in history and the two ships reached 67° 15' S by 39° 35' E , where their course was stopped by ice. Cook then turned northward to look for French Southern and Antarctic Lands , of

15480-428: 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 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

15609-451: Was changed. A reservation had also been lodged by Australia regarding the Southern Ocean limits. Effectively, the third edition—which did not delineate the Southern Ocean leaving delineation to local hydrographic offices—has yet to be superseded. Despite this, the fourth edition definition has partial de facto usage by many nations, scientists, and organisations such as the U.S. (the CIA World Factbook uses "Southern Ocean", but none of

15738-466: Was circulated to IHO member states in August 2002 (sometimes referred to as the "2000 edition" as it summarized the progress to 2000). It has yet to be published due to 'areas of concern' by several countries relating to various naming issues around the world – primarily the Sea of Japan naming dispute – and there have been various changes, 60 seas were given new names, and even the name of the publication

15867-529: 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

15996-586: Was later named the Ross Ice Shelf . Mount Erebus and Mount Terror are named after two ships from his expedition: HMS  Erebus and HMS  Terror . The Imperial Trans-Antarctic Expedition of 1914, led by Ernest Shackleton , set out to cross the continent via the pole, but their ship, Endurance , was trapped and crushed by pack ice before they even landed. The expedition members survived after an epic journey on sledges over pack ice to Elephant Island . Then Shackleton and five others crossed

16125-418: Was no land connection between New Zealand and Tierra del Fuego . Turning south again, Cook crossed the Antarctic Circle for the third time at 109° 30′ W before his progress was once again blocked by ice four days later at 71° 10′ S by 106° 54′ W . This point, reached on 30 January 1774, was the farthest south attained in the 18th century. With a great detour to the east, almost to the coast of South America,

16254-472: 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

16383-561: Was separated by sea from any continuous southern continent. The visit to South Georgia by Anthony de la Roché in 1675 was the first-ever discovery of land south of the Antarctic Convergence , i.e. in the Southern Ocean/Antarctic. Soon after the voyage cartographers started to depict " Roché Island ", honouring the discoverer. James Cook was aware of la Roché's discovery when surveying and mapping

16512-468: Was then known, and reported the discovery "of an Antarctic continent west of the Balleny Islands " on 25 January 1840. That part of Antarctica was later named " Wilkes Land ", a name it maintains to this day. Explorer James Clark Ross passed through what is now known as the Ross Sea and discovered Ross Island (both of which were named for him) in 1841. He sailed along a huge wall of ice that

16641-439: 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

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