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the northern polar region of the globe, including the outskirts of the continents of Eurasia and North America and nearly all of the Arctic Ocean (except the eastern and southern areas of the Norwegian Sea) and all its islands (except the coastal islands of Norway), as well as the adjoining sections of the Atlantic and Pacific oceans.
Natural features, GENERAL INFORMATION. The arctic is the region of the globe adjoining the north pole, bounded on the south by the arctic circle (situated at 66°33’ N lat.), within the limits of which the phenomena of polar day and polar night occur. Within these boundaries the area of the arctic comprises 21 million sq km. Some specific natural features of the arctic are a low radiation balance, an average temperature of close to 0°C during the summer months, a negative average annual temperature, chiefly solid atmospheric precipitation throughout most of the year, the year-round presence of ice on the land in the form of glaciers, subterranean ice and permafrost, treeless land, and ice on areas of ocean water. These characteristics permit the classification of the arctic as a special natural terrain and geographic region. The boundary of this region is usually drawn along the southern limit of the tundra zone, near the outline of the July isotherm of 10°C on land and 5°C on the sea. In some places this border passes north of the arctic circle; in others, south of it. Within these limits, the area of the arctic (including the water surface) comprises about 27 million sq km (5.3 percent of the earth’s surface). On the continents the boundary of the arctic region lies at approximately 70° N lat. (with the exception of the southern part of Greenland, the Labrador Peninsula, and adjoining sections of the Atlantic Ocean) and coincides with the average position of the arctic front. In this case the area of the arctic is reduced by approximately 10–15 percent. The land area of the arctic is about 10 million sq km. There are two natural zones—the arctic deserts and the tundras—within the boundaries of the arctic.
TERRAIN. The surface of the continental part of the arctic is formed chiefly by the low-lying edges of the eastern European and western Siberian plains and the northern Siberian, Yana-Indigirka, and Kolyma lowlands. There are mountains in only a few areas; the highest are the Byrranga Mountains on the Taimyr Peninsula (altitudes to 1,146 m), the northern section of the Verkhoiansk Range, and the mountains of the Chukchi Peninsula. Within the boundaries of the continental section of North America, most of the area is taken up by hilly plateaus ranging in altitude from 400 to 700 m (the arctic plateau and others). The majority of arctic islands are of continental origin, and they have chiefly low mountain and lowland topography. The highest mountains are found in eastern Greenland (Gunnbjorns Mountain, 3,700 m—the highest peak in the arctic), on Baffin Island (2,591 m), and on Ellesmere Island (2,929 m).
A large part of the arctic—approximately 13 million sq km—is occupied by the Arctic Ocean. There is a widely developed shelf area here with depths of less than 200 m; the area is occupied by the outlying seas—the Barents Sea, the White Sea, the Kara Sea, the Laptev Sea, the East Siberian Sea, and the Chukchi Sea. The bottom of these seas is a submarine continuation of the platformal structures of the land. The transitional zone consists of a continental slope ranging in depth from 180 to 3,000 m. The central part of the ocean—the arctic basin—is an area of deep sea trenches (reaching a depth of 5,449 m in the Nansen Trench) and submarine ridges, the most important of which is the Lomonosov Ridge.
GEOLOGICAL STRUCTURE. The arctic is a region where the structures of the Atlantic and Pacific sectors of the earth join. Complex areas of Precambrian, Paleozoic, and Meso-Cenozoic deposits and magmatite formations of various composition form the structure of the arctic land, the adjoining shelf, and the islands. Included within the boundaries of the arctic are ancient platform regions divided into Baikal, Caledonian, Hercynian, and Mesozoic folded systems. The ancient platform regions with a pre-Baikal crystalline foundation include the northern part of the eastern European and Siberian platforms and the northern edges of the Canadian and a large part of the Greenland shields. The Barents-Kara, Hyperborean, and western Siberian are younger Baikal-Paleozoic platforms. Among the ancient folded formations are the baikalites (Timan, Medvezhii Island, northeastern Greenland, and Ellesmere Island), as well as the Caledonites of Scandinavia, western Spitsbergen, eastern Greenland, Cornwallis Island, and the northwest section of Severnaia Zemlia. Among the younger folded formations are the Hercy-nian (Pai-Khoi-Novaia Zemlia, Innuit, and Taimyr-Severnaia Zemlia) and Mesozoic (Novosibirsk-Chukchi and North Alaskan) fold systems. The continental structures probably continue beyond the shelf in the submarine Lomonosov and Mendeleev ridges and in the Alpha Ridge. A midocean volcanic ridge stretches from the Atlantic Ocean into the arctic regions. Its separate links—the Iceland-Jan Mayen, Mona, Knipovich, and Gakkel’ ridges—constitute sections of a mobile zone stretching from the Atlantic across the arctic to the Pacific Ocean.
CLIMATE. Because of the polar day and night, the amount of solar radiation that reaches the area during the year is extremely uneven. The radiation balance in southern areas of the arctic is positive and constitutes 420–630 megajoules per sq m per year [mJ/(m2 • yr)], or 10–15 kilocalories per sq cm per year [kcal/(cm2 • yr)]—that is, one-half to one-third of what it is in the temperate zones. In the arctic basin, however, the balance is usually negative—the loss of heat is 85–125 mJ/(m2 • yr) or 2–3 kcal/(cm2 • yr). However, this loss is compensated for by an inflow of warm air and water masses into the arctic.
During the winter intensive cyclonic activity covers most of the arctic. The cyclones, which come from the North Atlantic Ocean and less often from the Pacific Ocean, are the source of the highest arctic winter air temperatures, maximum cloud cover and precipitation, sharp weather changes, and frequent strong winds. Anticyclonic circulation in winter develops chiefly in the Siberian area of the arctic and to a somewhat lesser extent in the Pacific Ocean section of the Arctic Basin—in the area of Canada and Greenland. These areas are marked by very low atmospheric temperatures, very slight cloud cover, scanty precipitation, and light or medium winds. In the summer the nature of atmospheric circulation in most of the arctic is the opposite of winter circulation, but it has little influence on the climate, since the circulation is less intense than in the winter. The climate of almost the entire Atlantic area of the arctic is influenced by the warm North Atlantic Current. The influence of the warm Pacific Ocean waters is significantly weaker because of their smaller inflow through the comparatively narrow and shallow Bering Straits.
The average temperature in January—the coldest winter month in the arctic—ranges between -2° and -4°C in the southern section of the Atlantic area to —25°C in the northern part of the Barents Sea, the western part of the Greenland Sea, and the Baffin and Chukchi seas and between -32° and -36°C in the Siberian area of the arctic, the northern part of the Canadian Basin, and adjoining areas of the Arctic Basin and -45° to -50°C in the central part of Greenland. The minimum temperature in these areas sometimes falls as low as -55° to -60°C; it is only in the Arctic Basin that it does not fall below -45° or -50°C. When deep cyclones penetrate the area, the temperature sometimes rises to between —2° and -10°C. As a result of severe cooling of the surface in those areas, temperature inversions occur constantly. The absolute humidity of the air is low (the partial pressure of water vapor ranges from 0.5 to 2–3 mbar); the relative humidity is high (80–90 percent). Winter cloud cover is particularly great in the South Atlantic area of the arctic; annual precipitation there ranges from 350 to 400 mm. In the Siberian and Canadian areas clear weather predominates; annual precipitation is between 150 and 200 mm in the Siberian area and close to the north pole and 100–120 mm in the Canadian area. The winds—the winter monsoon—are predominantly south and southwest over the entire Soviet coastal area of the arctic. In the Atlantic and Pacific ocean areas, the winds are mostly variable and strong, and blizzards are frequent. The bora (wind velocity more than 40 m/sec) often arises in many mountainous regions. The average temperature of the air in July—the warmest summer month—ranges from 0° to - 1°C in the Arctic Basin; near the coast it rises to 2° to -3°C and in the continental areas to 6°-10°C. In central Greenland the average July temperature is -10° to -12°C. Maximum temperatures in the Arctic Basin may go as high as 4°-5°C; on the coast they may reach 20°-25°C, and far from the seas they may reach 30°C. Frosts are possible all summer. The temperature sometimes falls to -2° or -4°C in the southern areas and to - 5° to - 7°C in the Arctic Basin. Relative humidity over the Arctic Basin is 95–98 percent, as a result of which fogs and low stratus clouds are frequent during the summer, and drizzling rains—often mixed with wet snow—and chiefly moderate winds prevail.
Because of the harsh climate, the temperature of the oceanic waters is low. In the areas of drifting pack ice the temperature of the surface layer of waters (100–200 m thick) is close to -2°C the entire year. The water warms up to several degrees above zero Centigrade in the areas that become free of ice in the summer. However, a large quantity of heat is brought to the arctic by warm currents.
Considerable climatic fluctuation has been observed in the arctic. Since about 1920 the atmospheric temperature of the arctic has begun to rise. The atmospheric temperature in several winter months in the 1930’s and 1940’s rose by 5°-7°C compared with the end of the 19th century, as a result of which the arctic ice pack became thinner, the overall ice cover of the seas diminished, and the glacial area shrank. The rise in average temperature in the frigid and temperate latitudes is connected with the intensification of general atmospheric circulation, which was also intensified by the warm North Atlantic Current, thereby raising the temperature and salinity of the water in the arctic seas. Since the 1950’s the air temperature in the arctic has begun to decline.
SEA ICE AND GLACIERS. A large section of the water surface of the arctic is covered by drift ice during the entire year (approximately 11 million sq km in the winter and about 8 million sq km in the summer). The thickness of the ice ranges from 0.8 to 1.8 m for annual ice and from 3 to 4 m for perennial ice. Hummocks are usually 3–5 m high, and in some instances they reach 10–15 m. There are icebergs and ice islands, sections that have broken off the shelf glaciers (mainly from the area of Ellesmere Island). Because of the drift ice the arctic seas are extremely difficult to navigate and are accessible to transport ships (usually accompanied by icebreakers) only for the two or three summer months.
A large portion of the surface of the arctic islands and mountains within the continental part of the arctic is covered by thick glaciers, the total area of which exceeds 2 million sq km. Glaciers cover from 30–40 percent (Novaia Zemlia and Severnaia Zemlia) to 83–90 percent (Greenland, Spitsbergen, and Franz Josef Land) of the territory of the islands. The thickness of the glaciers does not exceed 700–1,000 m (except in Greenland, where it reaches 3,408 m with an average thickness of 1,515 m). The principal areas of glaciation are concentrated in the Atlantic region, which is a more important part of the arctic—1.8 million sq km in Greenland, 56,000 sq km in the Soviet arctic, and 213,000 sq km on the islands of the Canadian arctic archipelago, Spitsbergen, and Alaska.
On the islands, sheet glaciers, cap glaciers, and glacier tongues predominate; in the mountainous regions (the Brooks Ridge, the Byrranga Mountains, and others), cirque and valley glaciers. On Novaia Zemlia and the Spitsbergen archipelago there is some semisheet glaciation (rafted ice). Small shelf glaciers are found on Ellesmere Island, Franz Josef Land, and Severnaia Zemlia. Relict and embryonic slope glaciers are characteristic of the coastal regions.
A particular feature of arctic terrain is the wide distribution of perpetually frozen rock, characterized by a thickness of up to 500 m, a very low temperature (below - 10°C), and a thin layer (no more than 60–70 cm) of seasonal thawing.
RIVERS AND LAKES. Within the land boundaries of the arctic, in addition to small rivers, there are estuaries of the great rivers of Eurasia and North America—the Pechora, Ob’, Enisei, Piasina, Khatanga, Anabar, Lena, lana, Indi-girka, Kolyma, Colville, and Mackenzie. These rivers are in the lowlands and usually flow in broad valleys, frequently forming large gulfs in the estuaries. The rivers influence the permafrost condition, pushing it far from the valleys and destroying it underneath their channels. They have a moderating influence on the climate of the adjoining arctic regions. The action of the river waters continues into the sea for several hundred kilometers from the river mouth and affects the hydrological and ice regimen of the seas.
The small rivers on the islands are fed by snowfall or glaciers. The rivers are frozen for nine to ten months a year; some freeze through to the bottom. On the continents they open up in May-June and freeze in October; on the islands they open up in the middle of July and freeze at the beginning of September.
There are many lakes within the boundaries of the continental tundras and on the islands; they are covered with ice most of the year. The largest lake is Taimyr, located on the peninsula of the same name.
SOILS. Arctic soils are characteristic of the islands in the Arctic Ocean. Because of the low air temperature, permafrost, the development of solifluction, and excess moisture, soil formation processes are retarded; as a result, the soils are poor in humus, do not form thick layers, and have a reduced profile and poorly defined genetic layers. Arctic soils are either weakly acidic or nearly neutral in reaction; there are no reduction processes (gley).
The tundra zone, which comprises the continental section of the arctic and some of the southern islands in the Arctic Ocean, has tundra soils. These soils are characterized by comparatively large accumulations of organic substances, low microbiological activity, mobility of humus, acidity, developed gley processes, division into a small number of genetic layers, and the presence of some permafrost. There are also various kinds of turf-like podzolized soils containing humus and gley; the average humus content is 4–5 percent (up to 10–12 percent in the upper layers of the turf soils).
REFERENCESGorbatskii, G. V. Severnaia poliarnaia oblast’, Leningrad, 1964.
Gorbatskii, G. V. Fiziko-geograficheskoe raionirovanie Arktiki, part 1. Leningrad, 1967.
Prik, Z. M. “Osnovnye rezul’taty meteorologicheskogo izucheniia Arktiki.” Problemy Arktiki i Antarktiki, 1960, no. 4.
“Problemy poliarnoi geografii.” Trudy Arkticheskogo i Antarkticheskogo nauchno-issledovatel’skogo instituta, 1968, vol. 285.
“Geologiia Sovetskoi Arktiki.” Moscow, 1957. (Trudy nauchno-issledovatel’skogo instituta geologii Arktiki, vol. 81.)
Z. M. PRIK, A. O. SHPAIKHER, and B. KH. EGIAZAROV (geological structure)
The system of sectors arose from a prolonged de facto demarcation of the rights and interests of the respective states and from the subsequent recognition of the priority of study and development of the various arctic areas. By the beginning of the 20th century, this division had received universal international recognition and was fixed in international law. In the 1930’s it was recorded in the domestic legislation of the above-mentioned states. (For example, on June 27, 1925, Canada adopted an amendment to the Northwest Territories Act.) In the same period, similar legislation was enacted in the USSR, Norway, and Denmark. The question of Denmark’s arctic sector was settled in 1933, when the International Court of Justice decided the argument between Norway and Denmark concerning Greenland in favor of Denmark. Norway has sovereignty over the Spitsbergen archipelago under the Paris Treaty of 1920, which the USSR signed in 1935.
The Soviet polar sector is the largest in the arctic (about 9 million sq km, of which 6.8 million sq km is water). Russia’s rights to the islands in the Arctic Ocean, deriving from discoveries, long-term possession, and development, were proclaimed in 1916 and subsequently confirmed in a note of the People’s Commissariat of Foreign Affairs of the USSR on Nov. 6,1924, in connection with attempts by Canada and the United States to gain a foothold on Wrangel and Herald islands. A resolution of the Presidium of the Central Executive Committee of the USSR on Apr. 15,1926, proclaimed all the land and islands to be the territory of the USSR. (The only exception was those islands that at the time of promulgation of the resolution had already been recognized by the Soviet Union as the territory of foreign states—the eastern islands of the Spitsbergen archipelago situated between 32° and 35° E long, and belonging to Norway—Sobrante zakonov SSSR, 1926, no. 32, p. 203.)
Since the majority of straits through which the Northern Sea Route passes are part of the territorial waters of the USSR, prior permission of the Soviet government is required for the passage of any foreign military vessel along that route. Passage of foreign merchant vessels is unrestricted.
The October Revolution opened up a new era in the study and development of the arctic. For the first time, Soviet arctic research began to proceed systematically, with the use of icebreakers, aviation, radio, and other technical facilities. In the 1920’s major research was done in the arctic by the Floating Marine Scientific Institute (Plavmornin), the Northern Scientific and Trade Expedition, and the Polar and Yakut commissions of the Academy of Sciences of the USSR. Between 1930 and 1935 numerous Soviet expeditions (on the Sedov under O. Iu. Shmidt in 1930, on the Taimyr under A. M. Lavrov in 1932, on the Rusanov under R. L. Samoilo-vich in 1932, and on the Sadko under G. A. Ushakov in 1935) conducted extensive and extremely valuable research in the waters between Greenland, Franz Josef Land, the northern tip of Novaia Zemlia, and Severnaia Zemlia. Many islands, capes, bays, and straits were discovered. In 1930–32, G. A. Ushakov and N. N. Urvantsev were the first to explore and map the Severnaia Zemlia archipelago. In 1932 an expedition on the Sibiriakov (under O. Iu. Shmidt) sailed the Northern Sea Route in the course of one navigational season. This was the first step in the broad utilization of the Northern Sea Route. The first experimental attempt to navigate the Northern Sea Route with a nonicebreaker was made in 1933 by the Cheliuskin. In 1937, Severnyi Polius (North Pole, SP-1), the first drifting station, was organized in the north pole area under the direction of I. D. Papanin. In the same year V. P. Chkalov.G. F. Baidukov, and A. V. Beliakov made the first transarctic flight, from Moscow to the United States. The forced drift of the Sedo ν (October 1937-January 1940), under K. S. Badigin. made it possible to conduct a series of observations in a hitherto completely unexplored region of the Arctic Basin. In 1937 the transport ship Mossovet succeeded for the first time in sailing over the Northern Sea Route in both directions in a single navigational season. In 1941 a Soviet air expedition was sent to the area of the pole of relative inaccessibility (pilot, I. I. Cherevichnyi; navigator, V. I. Akkuratov). A new method of studying the central arctic was initiated in 1948: small groups of scientists would land on ice floes in previously designated places with the help of aircraft and remain there for short periods. Groups of this kind discovered the submarine Lomonosov Ridge. In 1950 the second drifting polar station (SP-2) was established among the drift ice of the central arctic under the direction of M. M. Somov. Since 1954 two Soviet drifting Severnyi Polius stations have been conducting a year-round watch in the central arctic. There is also a large network of drifting automatic radiometeorological stations (DARMS) in the Soviet arctic that service navigation. Each summer expeditions from the Arctic and Antarctic Scientific Research Institute and the Hydrographic Administration of the Main Northern Sea Route Administration (Glavsevmorputi) conduct physical-geographical and oceano-graphical research in the seas and on the arctic coast.
After the Second World War the United States and Canada became more active in arctic research. Since 1946 both countries have been conducting oceanographic research in the eastern section of the Chukchi and Beaufort seas. A number of expeditions have been conducted in the arctic waters that wash the shores of Canada, Greenland, and Jan Mayen and Ellesmere islands. In 1944 the Canadian G. Larsen on the schooner St. Roch first sailed through the Northwest Passage in a single navigational season. Since 1951 the United States has organized a number of high-latitude air expeditions and drifting stations in the Arctic Basin.
REFERENCESVize, V. Iu. Moria Sovelskoi Arktiki: Ocherki po istorii issledovaniia [3rd ed.]. Moscow-Leningrad, 1948.
Zubov, N. N. V tsentre Arktiki: Ocherki po istorii issledovaniia i fizicheskoi geografii Tsentral’noi Arktiki. Moscow-Leningrad, 1948.
Gakkel’, Ia. Ia. Nauka i osvoenie Arktiki. Leningrad, 1957.
Istoriia otkrytiia i osvoeniia Severnogo morskogo puti, vols. 1–3. Moscow-Leningrad, 1956–62.
Magidovich, I. P. Ocherki po istorii geograficheskikh otkrytii. Moscow, 1967.
Deriugin, K. K. Sovetskie okeanograficheskie ekspeditsii. Leningrad, 1968.
Population density in the non-Soviet part of the arctic is 0.03 persons per sq km. The native population is Eskimo. Americans and Europeans are concentrated chiefly in the mining centers and military bases. The principal populated communities are Barrow (Alaska, United States), Inuvik and Resolute Bay (Canada), and Thule, Egedesminde, Søndre Strømfjord, and Mesters Vig (Greenland).
Economy. Before the Great October Socialist Revolution, the peoples of the Soviet section of the arctic were at a low level of development. In the years of Soviet power the significance of the arctic in the country’s economy has risen immensely. Unique deposits of valuable minerals have been explored. The discovery in the 1920’s of the largest apatite deposits in the world (in the Khibiny Mountains, Kola Peninsula) created excellent possibilities for meeting the Soviet Union’s demand for the raw materials of phosphate production; the ores there contain another valuable component—nephelines—and some rare metals. Exploration and development of copper and nickel ore deposits in northern Krasnoiarsk Krai laid the foundation for the establishment of a large mining and metallurgical combine in Noril’sk. Extensive geological prospecting in the Pechora basin led to the discovery and development of coal deposits (the center is in Vorkuta) and oil, and this in turn led to the establishment of a heat and power base in the Far North. Deposits of tin, gold, tungsten, mercury, and other metals have also been prospected. Transportation facilities have been considerably developed. The Northern Sea Route, which linked the European and Far Eastern Soviet ports and the mouths of the navigable rivers of Siberia into a single transportation system, and facilitated the utilization of the natural resources of the arctic and its economic development, played an enormous part in the development of the arctic. This route has turned into a navigable highway for mass cargoes; powerful icebreakers ensure navigation. Aviation—which provides regular links among the various points in the arctic and between the arctic and other parts of the USSR—is of great significance to the arctic areas. River shipping has expanded; new ports have been built, and old ones have been reconstructed. Centers of polar agriculture have been established around towns and industrial centers.
In the non-Soviet part of the arctic (Canada, Alaska), exploratory and prospecting work is under way for oil (major oil deposits have been discovered in northern Alaska in the vicinity of Prudhoe Bay), gold and copper (in the area of the Coppermine River), and iron ore (on northern Baffin Island). There is a small amount of coal mining on Disko Island. The Eskimos, who are chiefly engaged in hunting for fur-bearing and sea animals, have a semisubsistence economy. Fishing and fish processing are the main occupations in Greenland. Roads, ports, and air fields, principally of strategic significance, have been built in Greenland. There is a large US army and air force base in Thule. There is a line of radar stations along the 70° N lat. line from the western coast of Alaska to the eastern coast of Greenland.