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Related to Antarctic: Antarctic Treaty, Antarctic Circle
the south polar region, including the continent of Antarctica and the surrounding oceanic area of the Southern Ocean and small islands.
General information. The boundary of the antarctic is the line of the northern position of the Antarctic Convergence (the interface of the northern, comparatively warmer surface waters and the southern, cold surface waters), most of which lies between 48° and 60° S latitude. The antarctic also includes Prince Edward, Crozet, Macquarie, and other islands located near that line. Within those boundaries the area of the antarctic is approximately 52 million sq km.
The antarctic lies in two geographical zones—the antarctic and the subantarctic. The former comprises the antarctic continent and the surrounding area of drift ice, together with the islands located there; the latter comprises the islands and ocean areas that either never freeze over or do so only in the winter. The dividing line between the two zones lies in the ocean; only the northwestern tip of the Antarctic Peninsula has transitional antarctic to subantarctic features.
Terrain. The edge of the antarctic continental shelf lies deeper than that of other continental shelves (average, 500 m). The continental shelf itself has extensive depressions and troughs, some of which descend to 1,000 m and more. These depressions often continue beneath the antarctic ice covering. The outlying antarctic seas are almost entirely within the boundaries of the continental shelf (the Ross Sea, the Weddell Sea, the Bellingshausen Sea, the Sea of Cooperation, and others). A steep continental slope leads from the continental shelf to the ocean bed, which has a depth of 4,000–5,000 m. Large submarine elevations and ridges (the Australian-Antarctic Rise, the African-Antarctic Range, and the South Pacific Rise) divide the ocean bottom into wide basins—the African-Antarctic Basin, with depths of up to 6,972 m; the Australian-Antarctic Basin, reaching a depth of 6,089 m; the Bellingshausen Basin, as deep as 5,395 m; and a number of smaller basins. The narrow South Sandwich Trench, with maximum depths for the Antarctic Ocean of as much as 8,428 m, stretches alongside the South Sandwich Islands.
The mountain ranges that separate the basins have a very complex structure and topography. Many of their peaks rise nearly to sea level, and some rise above, forming islands. Bouvet Island, Prince Edward Island, and Crozet Island are situated on the African-Antarctic Range and its spurs; Ker-guelen and Heard islands are situated on the submerged Kerguelen-Gaussberg Ridge; Macquarie Island is on the submerged Macquarie Mountains; South Georgia, the South Sandwich, and the South Orkney islands are on the submerged South Antilles Range. Some of the mountains are volcanic cones, rising sharply from the bottoms of the deep basins nearly to the ocean surface. Some cones reach an altitude of 3,000–4,000 m above the trench bottom. The subantarctic islands—South Georgia, Kerguelen, Heard, the South Sandwiches, and others—have largely mountainous terrain and reach elevations of 2,934 m (South Georgia) and 2,745 m (Heard Island).
The antarctic has two main categories of terrain —continental and oceanic. The morphological structures of the continental part, which occur on the antarctic continent, continue on the bottom of the encircling seas and form the continental shelf. The interior sections of the continental shelf have mostly block topography, caused by very recent dislocations. The outer area is a plain with some relict elevations at sites of erosion-resistant rock extrusions. Sloping and terrace plains, alternating in some places with areas of block structures, are widespread in the continental slope zone.
The ocean bed is characterized by development around the antarctic continent of accumulative plains of oceanic trenches ringed by elevation belts. The slanting, undulating terrain of these plains is being leveled by the accumulation of sedimentary deposits. One of the characteristic features of the belt of elevation is the wide development of volcanic highlands, ridges, and cones.
Climate. The antarctic is the harshest region on earth; its characteristics include low atmospheric temperatures, strong winds, snowstorms, and fog.
The situation of the antarctic in the high latitudes accounts for the relatively low annual radiation balance at the northern boundary of the region—1.25–1.7 gigajoules per sq m per year [gJ/(m2yr)], or 30–40 kilocalories per sq cm per year [kcal/(cm2 · yr)]—and the negative balances on the antarctic continent—up to-0.2 gJ/(m2.yr), or -5 kcal (cm2.yr) —and in the area of the sea ice, where it is due to the large albedo of the snowy surface.
Because of the sharp cooling of the air masses, an area of high pressure known as the Antarctic Anticyclone forms above the continent. Conversely, a cyclonic belt over which cyclones move from west to east forms over the relatively warmer ocean. Ascending currents of air predominate in cyclones, creating an insufficiency of air below and a surplus at high altitudes known as a high-altitude anticyclone. As a result, the comparatively warm and humid air rushes in from the ocean to the continent. The surplus air is moved off the continent by outward-blowing winds. The interlatitudinal exchange of air masses tends to produce a certain equalization of the air temperature. However, most of the antarctic, with its continental climate, is a region of perennial freezing temperatures. In the subantarctic areas the annual temperature variation is quite flat because of the great heat capacity of the water—the average temperature does not rise above 10°C in the warmest months, nor does it usually fall below 0°C in the north and - 10°C in the south in the coldest month.
The intrusion of cold masses of continental air toward the north and humid oceanic masses toward the south (toward the continent) causes pronounced weather changes within short distances. Westerly winds, often of hurricane force—up to 75 m/sec—prevail in the northern antarctic (the so-called “furious fifties”). Easterly winds prevail near the continent, and when they merge with the mainly southeasterly, outward-blowing winds, they form a current of air along the coast blowing from east to west. Precipitation near the coast is almost exclusively in the form of snow; on the northern islands it often takes the form of rain as well. Annual precipitation varies from 300 to 500 mm near the east antarctic coast to 1,000 mm and more on the northwestern coast of the Antarctic Peninsula and the subantarctic islands.
The snow line, which is close to sea level all along the coast of Antarctica, rises as it moves northward and reaches an altitude of about 650–1,000 m at the South Georgia and Kerguelen islands. Consequently, the continent and the nearby islands have an ice covering, while the more northerly areas are mountainous, with some ice caps. Only the low islands (Macquarie and Crozet) have no glaciers at all.
Ocean waters and ice. The glacial continent is a source of cold fresh water that is discharged into the ocean mostly by melting icebergs. The mass of antarctic waters, cooled and with somewhat reduced salinity (temperatures -1.8°C to 1°C—2°C at the convergence line—and about 34 parts per thousand [‰] salinity), spread northward over the ocean surface to the Antarctic Convergence line, where they become heavier than the saline but warmer waters of the temperate zone that cover the antarctic waters north of the Antarctic Convergence. The layer of surface antarctic waters ranges in thickness from several dozen to several hundred meters. Below the surface waters are the deep waters, somewhat warmer and more saline (temperature 1°-2°C, salinity 34.5–34.7‰), which flow from the north as far as the continental slope and in some places enter the continental shelf. The average thickness of the deep water layer is 1,500 m. Still lower, toward the bottom, are the bottom—or bed—waters, which are formed near the continent on the continental shelf by the sharp cooling and descent of surface waters and then spread northward. The temperature of these waters is about 0°C, and their salinity is approximately 34.7 ‰. Because of the persistently strong easterly and southeasterly winds, a circular, east-to-west coastal current is formed near the antarctic coast. However, in the trailing sections of the passing cyclones, the air and water masses are carried from south to north, whereas in the leading sections they move from north to south. As a result of the quasi-stationary position of some of the low pressure centers, several quasi-stationary local circulations are formed around the continent, one of which is located in the Weddell Sea, another in the Ross Sea. The northern sections of these circulations merge between 60° and 40° latitude and form a mighty current of air and water masses moving from west to east. The axis of this current is the Antarctic Convergence, where a mixing of antarctic waters moving from the south and subtropical waters moving from the north takes place.
The Southern Ocean is the stormiest region of the world’s oceans. Its waves reach a height of 10–15 m, with maximums of 23 m. The height of the tides is 1–2 m, with a maximum of 3.25. The area covered by sea ice varies sharply from season to season. Toward the end of winter the belt of pack ice that encircles the continent reaches a width of 500–2,000 km (an area of about 20 million sq km). In the summer there is only a narrow, sparse strip of ice along the coast, broken in the vicinity of the Antarctic Peninsula, the Ross Sea, and the Sea of Cooperation. Only in the Weddell Sea does a thick massif of ice remain. In the summer the area of sea ice is approximately 2.5 million sq km. Annual sea ice reaches a thickness of 1.5–2 m—there is very little perennial sea ice in the antarctic. Icebergs are a very characteristic feature of the antarctic waters. They are numerous close to the coast and in some places form dense accumulations. They are comparatively infrequent far from the coast and only rarely cross the line of the Antarctic Convergence, although they have been observed in subtropical regions. Tabular icebergs are most characteristic of the antarctic. In some instances they reach 170 km in length and rise up to 50 m above the water (occasionally more than 100 m).
The distinctive character and origin of antarctic fauna and flora make it possible to classify the antarctic as a separate antarctic region.
REFERENCESSovetskaia kompleksnaia antarkticheskaia ekspeditsiia: Informa-tsionnyi biulleten’, issues 1–66. Leningrad, 1958–67.
Sovetskaia kompleksnaia antarkticheskaia ekspeditsiia: Materialy, vols. 1–51. Leningrad, 1959–67.
Problemy Arktiki i Antarktiki, issues 1–27. Leningrad, 1959–67.
Antarktika: Doklady kommissii, issues 1–6. Moscow, 1961–66.
Kotliakov, V. M. Snezhnyi pokrov Antarktidy i ego rol’ v sovremennom oledenenii materika. Moscow, 1961.
Rusin, N. P. Meteorologicheskii i radiatsionnyi rezhim Antarktidy. Leningrad, 1961.
Atlas Antarktiki, vol. 1. Moscow-Leningrad, 1966.
Barkov, N. I., and Zh. A. Tarasova. Desiat’ let sovetskikh issledovanii v Antarktike. Leningrad, 1968. (Bibliography of Soviet literature for 1956–65.)
Geografiia Antarktidy. Moscow, 1968.
British Antarctic Survey Bulletin, nos. 1–13. London, 1963–67.
Antarctic Research. London, 1964.
Antarctic Research Series, vols. 1–9. Washington, 1964–66.
Antarctic Bibliography, vols. 1–2, 1965–66.
Antarctic Journal of the United States, vols. 1—. Washington, 1966—.
The USSR always held that the legal status of the antarctic should be determined by an agreement among the interested states in which account would be taken of the lawful rights and interests of those states. In a note to Norway of Jan. 27, 1939, the USSR stated its position with regard to the national affiliation of the territories discovered and explored by Russian navigators and scientists at the beginning of the 19th century. Claims to antarctic territories were also advanced by the governments of the United States (in 1939) and Japan (1940). At the same time, the United States attempted to settle the problem of the legal status of the antarctic in its own way, with a view to establishing its own hegemony over the entire antarctic. In August 1948 the United States entered into unofficial negotiations with the countries that had advanced territorial claims in the antarctic. However, Norway, Chile, and Argentina reacted negatively to this. In a memorandum of June 7, 1950, the government of the USSR informed the participants in the abovementioned separate negotiations that it could not recognize as lawful any decision on the legal status of the antarctic made without the participation of the USSR and suggested that this question be discussed on an international level. This position received the support of all the interested states. On Oct. 15, 1959, a conference on the antarctic met in Washington with the participation of the USSR, the United States, England, France, Belgium, Norway, the Republic of South Africa, Argentina, Chile, and Japan. The conference drafted and approved the Antarctic Treaty of Dec. 1, 1959, which defines the current international legal status of the Antarctic.
The 1959 treaty establishes that the antarctic is to be used solely for peaceful purposes. Any measures of a military nature—such as the establishment of military bases and fortifications, the conduct of military maneuvers, or the testing of any kind of weapon—are specifically forbidden. The entire territory of the antarctic constitutes a neutralized and demilitarized zone, within the boundaries of which all actions for military purposes are prohibited in wartime as well as peacetime. Article II of the treaty proclaims the principle of freedom of scientific research in the antarctic. With a view toward promoting international cooperation for scientific research, the signatories of the treaty agreed to exchange information about plans for scientific work in the antarctic, scientific personnel between expeditions and stations, and also data and results of scientific observations (Article III).
Participation in the treaty implies neither the surrender of previously advanced claims of territorial sovereignty in the antarctic nor the recognition of these claims by signatories who had not previously recognized those claims (Article IV). The treaty provides that no new claims or extension of present claims to territorial sovereignty in the antarctic may be made as long as the treaty is in effect.
The resolutions of the treaty that concern its supervision are very important. Under Article VII, all areas of the antarctic—including all the stations, installations, and equipment in those areas, as well as all the marine and air vessels at points of loading and unloading cargo and personnel—are to be open at all times for inspection by any observers appointed under the treaty provisions. (The observers must be citizens of the member state that appoints them.)
REFERENCESMolodtsov, S. V. “Dogovor ob Antarktike.” Sovetskoe gosudarstvo i pravo, 1959, no. 5. Pages 64–72.
Movchan, A. P. “Pravovoi status Antarktiki—mezhdunarodnaia problema.” In Sovetskii ezhegodnik mezhdunarodnogo prava: 1959. Moscow, 1960. Pages 342–356.
“Dogovor ob Antarktike.” In Vedomosti Verkhovnogo Soveta SSSR, 1961, section 1, no. 31, p. 329.
SEARCH FOR THE SOUTHERN CONTINENT IN TEMPERATE LATITUDES AND DISCOVERY OF THE ANTARCTIC ISLANDS (16TH CENTURY TO THE FIRST QUARTER OF THE 19TH CENTURY). In 1501–02, A. Vespucci discovered South Georgia Island in the southern part of the Atlantic Ocean. In 1739–72, French expeditions discovered Bouvet and Kerguelen islands. In 1772–75, J. Cook’s British expedition circumnavigated the continent and approached South Georgia Island, discovered the Sandwiches, South Thule Island, and reached 71° 10’ S lat. in the Pacific Ocean, but did not sight land anywhere. After his voyage, Cook expressed the view that there might be a southern continent only in the vicinity of the south pole, in nonnavigable areas. In 1819 the British hunter and trapper W. Smith discovered the South Shetland I slands.
DISCOVERY AND FIRST EXPLORATIONS OF ANTARCTICA (19TH CENTURY). Credit for the discovery of Antarctica as an ice-covered continent belongs to a Russian round-the-world naval expedition under F. F. Bellingshausen and M. P. Lazarev, sailing on the sloops Vostok and Mirnyi. In January and February of 1820, Russian ships approached close to the ice shelf of Queen Maud Land four times. A Russian expedition discovered Peter I Island and Alexander I Land and several islands of the South Shetland Archipelago. In 1820–1821, British and American seal-hunting vessels under E. Bransfield and N. Palmer came close to the Antarctic Peninsula (Graham Land). In 1831–33 the British navigator J. Biscoe circumnavigated Antarctica and discovered Enderby Land and Adelaide and Biscoe islands. In 1838–42 three scientific expeditions visited the antarctic—a French expedition (led by J. Dumont d’Urville), an American expedition (led by Charles Wilkes), and a British expedition (led by J. Ross). The first expedition discovered Louis Philippe Land, Joinville Land, Adélie Land, and Clarie Land (and was the first to land on the coastal cliffs); the second discovered Wilkes Land; and the third discovered Victoria Land and the coastal islands and was the first to cross the gigantic Ross Ice Shelf and to estimate the location of the south magnetic pole.
These expeditions were followed by a 50-year period of calm in the antarctic. Interest in the antarctic increased toward the end of the 19th century, when the number of whales in the arctic declined as a result of rapacious destruction. Several expeditions sailed to the antarctic—a Scottish expedition on the Balleny (1893), which discovered Oscar II Land, which was later given that name by the Norwegian expedition on the Jason and the Antarctic (1893–94) that discovered the Larsen Coast and landed on the coast of Antarctica in the vicinity of Cape Adare; a Belgian expedition (1897–99) under A. deGerlache, which wintered in the antarctic on the drifting ship Belgica; and a British expedition (1898–99) that wintered at Cape Adare on the Southern Cross (C. E. Borchgrevink was in charge of the wintering party).
BEGINNING OF THE EXPLORATION OF THE COAST OF ANTARCTICA (1900–55). In 1901–04 the British expedition of R. Scott, in addition to conducting marine research, undertook the first major sledging expedition from McMurdo Sound into the interior of Antarctica (as far as 82° 17’ S latitude). A German expedition under E. Drygalski conducted winter observations on the coast of Wilhelm II Land, which it had discovered. A Scottish oceanographic expedition under William Bruce on the Scotia discovered Coats Land in the eastern part of the Weddell Sea. A French expedition under J. Charcot on the Français discovered Loubet Land.
Expeditions to the south pole evoked great interest. In 1908 the Englishman Ernest Shackleton departed from McMurdo and reached 88° 23’ S latitude. In 1911, moving from the eastern part of the Ross Barrier, the Norwegian R. Amundsen was the first to reach the south pole (Dec. 14–16). The Englishman R. Scott made the trip on foot from McMurdo and was the second to reach the south pole (Jan. 18, 1912). On the return trip, R. Scott and his companions perished. An Australian expedition under D. Mawson explored the ice shelf of Eastern Antarctica from two land bases in 1911–14.
In 1928 an American aircraft appeared in Antarctica for the first time. In 1929, R. Byrd flew over the south pole from a base he had established in Little America. Marie Byrd Land was also discovered from the air. In 1929–31 the British-Austrialian-New Zealand Antarctic Research Expedition (BANZARE) explored Knox Coast and discovered Princess Elizabeth Land east of it. During the second International Polar Year (IPY), an expedition under R. Byrd worked in Little America (1933–35). Glaciological and geological explorations were carried out in the mountains of Queen Maud Land and Marie Byrd Land by sledge and aircraft. R. Byrd wintered alone on the first advance weather station in the interior of the Ross Ice Shelf. In 1935, L. Ellsworth made the first transantarctic flight (from the Antarctic Peninsula to Little America).
The whaling industry that developed in the antarctic after World War I required a study of the biological life of the ocean. For this purpose the British Discovery Committee carried out a number of oceanographic trips. In 1933–37 an expedition under L. Christensen, sailing the Thorshavn along the coast, discovered the Leopold and Astrid Coast, the Prince Harald Coast, and Lars Christensen Land. Coastal exploration was carried out by the expeditions of J. Rymill (1934–37) in the Penóla, which chartered more exactly—and was the first to cross—the territory of the Antarctic Peninsula and discovered the George VI Straits; A. Ritscher (1938–39) in the Schwabenland, which carried out an aerial survey of the new mountain area, Queen Maud Land; and R. Byrd (1939–41), which studied the area from the Beardmore Glacier to the Shackleton Glacier from the air.
In the 1940’s and 1950’s a network of land-based stations and bases was established to study the outlying parts of the antarctic. The American “Highjump” (1946–47) and “Windmill” (1947–48) expeditions, using ships and aircraft, performed an aerial photo survey of sections of the coast between Little America and the Antarctic Peninsula and between Little America and Wilkes Land, carried out astronomical and geodesic research, and discovered the Coats Coast and the Bunger “oasis.” A British-Swedish-Norwegian expedition into the interior of Queen Maud Land (1950–52) determined the thickness of the ice covering with seismological instruments, discovered new mountain ranges, and made an aerial photo survey of a significant area.
JOINT SYSTEMATIC EXPLORATION OF THE ANTARCTIC SINCE 1955. In the period of preparations for the IGY, 11 countries set up 57 bases and stations on the ice sheet, islands, and the coast, from which expeditions into the interior of the continent and general scientific observations were performed. In 1955–58 the USSR conducted two marine and wintering expeditions—under M. M. Somov and A. F. Treshnikov—on the icebreaking oceanographic vessels Ob’ and Lena (the marine expeditions were under V. G. Kort and I. V. Maksimov). The Mirnyi scientific observatory (opened Feb. 13, 1956), the Oasis station, and the Pionerskaia, Vostok I, Komsomol’skaia, and Vostok intercontinental stations were built, and oceanographic explorations were carried out.
The United States conducted two expeditions —“Deepfreeze I” and “Deepfreeze II”—with the support of naval and air forces; a base at McMurdo and the Amundsen-Scott (south pole), Byrd, Hallett, and Wilkes stations were also established.
Synchronous observations conducted for the first time in the antarctic under the IGY program and then extended in the periods of international geophysical cooperation (1959–65) were combined with long-distance expeditions and flights into the interior of Antarctica. In 1957–67, Soviet scientists carried out 13 marine and wintering expeditions in the antarctic, continued observations at the old stations, and established new stations—Sovetskaia, Lazarev, Novolazarevskaia, and Molodezhnaia. In 1968, Soviet scientists established Bellingshausen Station on the South Shetland Islands. The most important expeditions into the interior of the continent by Soviet sledge and tractor trains starting from Mirnyi were in 1957 to the geomagnetic pole (under A. F. Treshnikov); in 1958 to the pole of relative inaccessibility (under E. I. Tolstikov); in 1959 to the south pole (under A. G. Dralkin); in 1964 from Vostok Station to the pole of relative inaccessibility and Molodezhnaia Station (under A. P. Kapitsa); and in 1967 on the route from Molodezhnaia Station to Novolazarevskaia Plateau Station via the pole of relative inaccessibility (under I. G. Petrov). Seismological, gravimetrical, geodesical, and glaciological observations conducted during the expeditions established that the native relief of eastern Antarctica was more complex and sculptured than had been thought previously. Soviet marine expeditions conducted parallel with the wintering expeditions studied the water masses and biological life of the Antarctic Ocean and conducted aerial photo surveys of most of the coast of eastern Antarctica; as a result of this, exact maps were drawn up.
In addition to stationary observations, American scientists carried out a number of transcontinental expeditions on cross-country vehicles in western Antarctica along the following routes: in 1957, Little America-Byrd Station-Sentinel Station; in 1958–59, Ellsworth Station-Dufek massif-Byrd Station (under V. Anderson and E. Thiel); in 1960, Scott Station-the mountainous regions of Victoria Land-Hallett Station (under van der Hoeven); in 1961, McMurdo-south pole (under A. Crary); and in 1962, Byrd Station-Sky High Station-Ellsworth Land. Glaciological research and cartography predominated in their programs. The American “Deepfreeze” marine expeditions explored the coast and waters of the western antarctic. As a result of geophysical and glaciological research, the American scientists clarified the nature of the subglacial relief of western Antarctica.
Scientists of other countries also performed considerable research in Antarctica. In 1957–58, British and New Zealand scientists under V. Fuchs and E. Hillary were the first to cross Antarctica on tractors, across the south pole from the Weddell Sea to the Ross Sea. Australian scientists organized expeditions from Mawson Station into the interior of Antarctica (under K. Mazer and P. G. Law). The Belgians conducted several expeditions across the ice sheet from Baudouin Station (under de Gerlache); French scientists worked at the Charcot and Dumont d’Urville stations. The Antarctic Treaty concluded in 1959 promoted the development of antarctic research under a coordinated program.
REFERENCESBellinsgauzen, F. F. Dvukratnye izyskaniia v Iuzhnom Ledovitom okeane i plavanie vokrug sveta. . . , 3rd ed. Moscow, 1960.
Pervaia russkaia Antarkticheskaia ekspeditsiia 1819–1821 gg. i ee otchetnaia navigatsionnaia karta. Leningrad, 1963.
Treshnikov, A. F. Istoriia otkrytiia i issledovaniia Antarktidy. Moscow, 1963.
Sullivan, W. Quest for a Continent. New York, 1957.
M. I. BELOV