Atlantic Ocean minerals. Mineral resources of the Atlantic Ocean and their extraction

Atlantic Ocean

Geographical position.The Atlantic Ocean stretches from north to south for 16 thousand km from subarctic to Antarctic latitudes... The ocean is wide in the northern and southern parts, narrowing in equatorial latitudes up to 2900 km. In the north it is connected with the Arctic Ocean, and in the south it is widely connected with the Pacific and Indian Oceans. It is bounded by the shores of North and South America in the west, Europe and Africa in the east and Antarctica in the south.

The Atlantic Ocean is the second largest ocean on the planet... The ocean coastline in the northern hemisphere is heavily dissected by numerous peninsulas and bays. There are many islands, inland and marginal seas near the continents. The Atlantic includes 13 seas, which occupy 11% of its area.

Bottom relief. Through the entire ocean (approximately at an equal distance from the coasts of the continents) passes Mid-atlantic ridge... The relative height of the ridge is about 2 km. Transverse faults divide it into separate segments. In the axial part of the ridge, there is a giant rift valley 6 to 30 km wide and up to 2 km deep. Both underwater active volcanoes and the volcanoes of Iceland and the Azores are confined to the rift and faults of the Mid-Atlantic Ridge. On both sides of the ridge, there are basins with relatively flat bottoms, separated by elevated uplifts. The shelf area in the Atlantic Ocean is larger than in the Pacific.

Mineral resources. Oil and gas reserves have been discovered on the shelf of the North Sea, in the Gulfs of Mexico, Guinea and Biscay. Phosphorite deposits have been discovered in the area of ​​uplift of deep waters off the coast of North Africa in tropical latitudes. Placer deposits of tin near the shores of Great Britain and Florida, as well as diamonds off the coast of South-West Africa, have been identified on the shelf in the sediments of ancient and modern rivers. Ferromanganese nodules are found in depressions off the coast of Florida and Newfoundland.

Climate.The Atlantic Ocean is located in all climatic zones of the Earth... The main part of the ocean is between 40 ° N latitude. and 42 ° S. - is located in subtropical, tropical, subequatorial and equatorial climatic zones. There are high positive air temperatures all year round. The sub-Antarctic and Antarctic latitudes have the most severe climate, and to a lesser extent the sub-polar, northern latitudes.

Currents.In the Atlantic, as in the Pacific Ocean, two rings of surface currents are formed... In the northern hemisphere, the North Passat Current, the Gulf Stream, the North Atlantic and Canary currents form a clockwise movement of waters. In the southern hemisphere, the South Tradewinds, Brazilian, Western winds and Benguela form a counterclockwise movement of waters. Due to the considerable length of the Atlantic Ocean from north to south, meridional water flows are more developed in it than latitudinal ones.

Water properties. The zoning of water masses in the ocean is complicated by the influence of land and sea currents. This is manifested primarily in the distribution of surface water temperatures. In many areas of the ocean, the isotherms near the coast deviate sharply from the latitudinal direction.

The northern half of the ocean is warmer than the southern, the temperature difference reaches 6 ° C. The average surface water temperature (16.5 ° C) is slightly lower than in the Pacific Ocean. The cooling effect is provided by the waters and ice of the Arctic and Antarctic. Salinity of surface waters in the Atlantic Ocean is high... One of the reasons for the increased salinity is that a significant part of the moisture evaporating from the water area does not return back to the ocean, but is transferred to neighboring continents (due to the relative narrowness of the ocean).

Many large rivers flow into the Atlantic Ocean and its seas: the Amazon, Congo, Mississippi, Nile, Danube, La Plata, etc.
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Οʜᴎ Carry out huge masses of fresh water, suspended material and pollutants into the ocean. In freshened bays and seas of subpolar and temperate latitudes, ice forms near the western coast of the ocean in winter. Numerous icebergs and floating sea ice impede shipping in the North Atlantic Ocean.

Organic world... The Atlantic Ocean is poorer in flora and fauna than the Pacific Ocean. One of the reasons for this is its relative geological youth and a noticeable cooling in the Quaternary period during the glaciation of the northern hemisphere. At the same time, in quantitative terms, the ocean is rich in organisms - it is the most productive per unit area.... This is primarily due to the widespread development of shelves and shallow banks, which are home to many bottom and bottom fish (cod, flounder, perch, etc.). The biological resources of the Atlantic Ocean are depleted in many areas. The ocean's share of global fisheries has declined significantly in recent years.

Natural complexes.In the Atlantic Ocean, all zonal complexes are distinguished - natural belts, except for the northern polar... Water northern subpolar belt rich in life. It is especially developed on the shelves off the coasts of Iceland, Greenland and the Labrador Peninsula.
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Temperate zone characterized by an intense interaction of cold and warm waters, its waters are the most productive regions of the Atlantic. Vast spaces of warm waters of two subtropical, two tropical and equatorial zones less productive than the waters of the northern temperate zone.

In the northern subtropical belt, stands out special natural aquatic complex of the Sargasso Sea... It should be said that it is characterized by increased water salinity (up to 37.5 ppm) and low bioproductivity. In clear water, pure blue colors grow brown algae - sargassum, which gave the name of the water area.

In the temperate zone of the southern hemisphere As in the north, natural complexes are rich in life in areas where waters with different temperatures and density of waters mix. In the subantarctic and antarctic belts Characterized by the manifestation of seasonal and permanent ice phenomena that affect the composition of the fauna (krill, cetaceans, notothenium fishes).

Household use. All types of human economic activities in marine areas are represented in the Atlantic Ocean. Among them, sea transport is of the greatest importance, followed by subsea oil and gas production, and only then is the catch and use of biological resources.

More than 70 coastal countries with a population of over 1.3 billion are located on the shores of the Atlantic. Many transoceanic routes with large volumes of freight and passenger traffic pass through the ocean. The most significant ports in the world in terms of cargo turnover are located on the coasts of the ocean and its seas.

The already explored mineral resources of the ocean are significant (examples are given above). At the same time, oil and gas fields are currently being intensively developed on the shelf of the North and Caribbean Seas, in the Bay of Biscay. Many countries that previously did not have significant reserves of these types of mineral raw materials are now experiencing economic growth due to their extraction (England, Norway, the Netherlands, Mexico, etc.).

Biological resources oceans have long been used intensively. At the same time, due to overfishing of a number of valuable commercial fish species, in recent years the Atlantic has been inferior to the Pacific Ocean in terms of fish and seafood production.

Intensive human economic activity in the Atlantic Ocean and its seas causes a noticeable deterioration of the natural environment - both in the ocean (water and air pollution, a decrease in the stocks of commercial fish species) and on the coasts. In particular, recreational conditions on the shores of the ocean are deteriorating. In order to prevent further and reduce the existing pollution of the natural environment of the Atlantic Ocean, scientific recommendations are being developed and international agreements are being concluded on the rational use of ocean resources.

Atlantic Ocean - concept and views. Classification and features of the category "Atlantic Ocean" 2017, 2018.

The Atlantic Ocean provides 2/5 of the world's catch, and its share decreases over the years. In subantarctic and Antarctic waters, notothenia, blue whiting and others are of commercial importance, in the tropical zone - mackerel, tuna, sardine, in areas of cold currents - anchovies, in the temperate latitudes of the northern hemisphere - herring, cod, haddock, halibut, sea bass. In the 1970s, due to overfishing of some fish species, the volume of fishery fell sharply, but after the introduction of strict limits, fish stocks are gradually recovering. In the Atlantic Ocean basin, several international conventions on fisheries are in force, aiming at the efficient and rational use of biological resources, based on the application of scientifically based measures to regulate fishing. The shelves of the Atlantic Ocean are rich in oil and other minerals. Thousands of wells have been drilled offshore the Gulf of Mexico and the North Sea. Phosphorite deposits have been discovered in the area of ​​uplift of deep waters off the coast of North Africa in tropical latitudes. Placer deposits of tin near the shores of Great Britain and Florida, as well as diamonds off the coast of South-West Africa, have been identified on the shelf in the sediments of ancient and modern rivers. Ferromanganese nodules are found in bottom basins off the coast of Florida and Newfoundland.
Due to the growth of cities, the development of shipping in many seas and in the ocean itself, a deterioration in natural conditions has recently been observed. Water and air are polluted, conditions for recreation on the shores of the ocean and its seas have deteriorated. For example, the North Sea is covered with many kilometers of oil spills. Off the coast of North America, the oil slick is hundreds of kilometers wide. The Mediterranean Sea is one of the most polluted on Earth. The Atlantic is no longer able to clean itself of waste on its own.

124. Physical and geographical regionalization of the Atlantic Ocean. At the level of physical and geographical zones, the following subdivisions are distinguished: 1. Northern subpolar belt (north-western part of the ocean, adjacent to Labrador and Greenland). In spite of low temperatures water and air, these areas are distinguished by high productivity, have always been of great commercial importance. 2. Northern temperate belt (extends far beyond the Arctic Circle into the Arctic Ocean). The coastal areas of this belt have a particularly rich organic world and have long been famous for the productivity of fishing regions. Northern subtropical belt (narrow). It is allocated, first of all, by the increased salinity and high water temperature. Life here is much poorer than in higher latitudes. The commercial value is not great, except for the Mediterranean (the pearl of the entire belt =) 4. Northern tropical belt. It is characterized by a rich organic world within the nerite zone of the Caribbean Sea and very rarefied within the open water area. Equatorial belt. It is distinguished by the constancy of temperature conditions, the abundance of atmospheric precipitation and the general richness of the organic world. 6. The southern tropical, subtropical and temperate zones, generally similar to those of the same name in the northern hemisphere, only the boundaries of the southern tropical and southern subtropical pass in the western part of approx. to the south (the influence of the Brazilian Current), and in the east - to the north (the influence of the cold Benguela Current) 7. Southern subpolar - important commercial value. 8. South polar! (in the north it is absent), are distinguished by the greatest severity of natural conditions, ice coverage and are much less populated.

125. Geographical position, size, boundaries, configuration of the Pacific Ocean. Pacific Ocean - greatest ocean of the earth. It accounts for about half (49%) of the area and more than half (53%) of the water volume of the World Ocean, and the surface area is equal to almost a third of the entire surface of the Earth as a whole. In terms of the number (about 10 thousand) and the total area (more than 3.5 million km 2) of islands, it ranks first among the rest of the Earth's oceans. Pacific Northwest and West limited the coast of Eurasia and Australia, in the northeast and east - the coast of North and South America. The border with the Arctic Ocean is drawn through the Bering Strait along the Arctic Circle. The southern border of the Pacific Ocean (as well as the Atlantic and Indian) is the northern coast of Antarctica. When the Southern (Antarctic) Ocean is distinguished, its northern boundary is drawn along the waters of the World Ocean, depending on the change in the regime of surface waters from temperate latitudes to Antarctic ones. Square The Pacific Ocean from the Bering Strait to the shores of Antarctica is 178 million km 2, the volume of water is 710 million km 3. Borders with other oceans south of Australia and South America are also conventionally drawn along the water surface: with the Indian Ocean - from Cape South East Point at about 147 ° E, with the Atlantic Ocean - from Cape Horn to the Antarctic Peninsula. In addition to a wide connection with other oceans in the south, there is a communication between the Pacific and the northern part of the Indian Ocean through the inter-island seas and straits of the Sunda Archipelago. North and western (Eurasian) shores of the Pacific Ocean dismembered seas (there are more than 20), bays and straits separating large peninsulas, islands and entire archipelagos of continental and volcanic origin. The shores of Eastern Australia, southern North America and especially South America are usually straight and difficult to access from the ocean. With a huge surface area and linear dimensions (more than 19 thousand km from west to east and about 16 thousand km from north to south), the Pacific Ocean is characterized by a weak development of the continental margins (only 10% of the bottom area) and a relatively small number of shelf seas. Within the intertropical space, the Pacific Ocean is characterized by clusters of volcanic and coral islands.

Oil and natural gas

The most important mineral resources of the Atlantic Ocean are oil and natural gas. Oil and gas shelves off the coast of North America include the shelf of the Labrador Sea, as well as the Georges Bank, Nova Scotia and St. Lawrence Bays.

On the eastern shelf of Canada, oil reserves are 2.5 billion tons, natural gas - 3.3 trillion. cub. m; on the continental slope and the eastern shelf of the United States - up to 0.54 billion tons of oil and gas - 0.39 trillion. cub. More than 280 deposits have been identified on the southern shelf of the United States, and more than 20 deposits off the coast of Mexico. More than 60% of Venezuela's oil is produced in the Maracaibo lagoon. Fields are actively exploited near Trinidad Island in the Gulf of Paria.

Oil and gas bearing areas are found on the shelves of the Gulf of São Jorge (Argentina) and the Gulf of Toduz-us-Santos (Brazil). The total reserves of the shelves of the Caribbean Sea are equal to 13 billion tons of oil and 8.5 trillion. cub. m. of natural gas. Oil fields have been discovered in the Irish and North (114 fields) seas, the Gulf of Guinea (50 on the Nigeria shelf, 37 in Gabon, 3 in the Congo, etc.). On the Mediterranean shelf, the forecasted oil reserves are 110-120 billion tons. There are deposits in the Adriatic, Aegean, Ionian seas, off the coasts of Egypt, Tunisia, Spain, etc.

Oil and gas basins

The largest oil and gas basins in the Atlantic Ocean include:

1. Gulf of Mexico oil and gas basin;
2. Maracaiba oil and gas basin.

The oil and gas basin of the Gulf of Mexico is located in the water area of ​​the Gulf and adjacent territories of Mexico, USA, Cuba, Belize, Guatemala. The total area of ​​the oil and gas basin is about 2.5 million square meters. km. The initial commercial reserves of oil and condensate (data for 1985) are 18.3 billion tons and natural gas - 14.6 trillion. cub. m.

In the mainland part of the basin, the first deposits were discovered in 1896 (USA), and on the shelf - in 1938 (USA). In the American part of the basin, the largest deposits were discovered in the 1930s. (Agua Dals Stratton, East Texas, Carthage, Cayu Island, Old Ocean), and in the Mexican part - in the 70s. (Iris Giraldas, Bermudez, Cantarell).

Remark 1

In total, more than 5 thousand oil and 4 thousand gas and gas condensate fields have been discovered in the oil and gas basin of the Gulf of Mexico. 95% of the deposits are in the United States.

Gulf of Mexico oil and gas basin confined to the southern regions of the Atlantic epigercyn platform, represented by the Gulf of Mexico depression and the Gulf Coast. The basin is formed by sedimentary rocks of the Mesozoic-Cenozoic period with the greatest thickness of 15 km. The entire section of the sedimentary cover is associated with oil and gas content.

The farthest offshore field has been identified at a distance of 240 km from the Louisiana coast. Some exploration wells are located at a distance of 260 km at a depth of 600 m. The oil in the outer zone is sweet and light. The sulfur content increases in deposits that are associated with the caps of the salt domes. In the inner regions of the basin, oils are of medium density, methane-naphthenic composition and high-sulfur.

Natural gases do not contain a large number of heavy homologues of methane and a lot of gas condensate. The main centers of natural gas production are Texas, Louisiana, Campeche Bay, Reform area.

On the territory of the Mexican oil and gas basin there is an extensive network of oil pipelines, gas pipelines, 75 oil refineries and 400 gas processing plants.

Maracaiba oil and gas basin is located in the north-east of Colombia, north-west of Venezuela, occupies the Venezuelan Gulf and the adjacent land area, Lake Maracaibo. The pool area is 86 thousand square meters. km, including about 30 thousand square meters. km. water area. The basin is surrounded by separate spurs of the Andes mountain system. The development of oil fields began in 1917. A total of 79 oil and 4 gas fields were discovered.

Initial oil reserves amounted to 6.6 billion tons, natural gas - 1.7 trillion. cub. m., on the shelf 5 billion tons and 1.2 trillion. cub. m respectively.

The coastal oil and gas accumulation zone Bolivar, which stretches for 3.5 thousand square meters, is distinguished separately. km. Bolivar unites 8 fields. Large oil field - Lama, containing 584 million tons. Potential oil resources are estimated at 9.3 billion tons, natural gas - 1.9 trillion. cub. m.

The Maracaibian oil and gas basin is formed mainly by terrigenous deposits of the Mesozoic and Cenozoic. The greatest thickness is 11 km. The reservoirs are sandstones and fractured limestones. A characteristic feature of the basin is the predominant oil-bearing capacity. Gas reserves represent 90% of the dissolved gas of oil fields. Oils are mostly viscous and heavy. Lighter oils are classified as Cretaceous deposits. The dissolved gas of the Bolivar zone contains heavy methane homologues and fatty.

The main centers for oil and gas processing are located in Punta Cardón and Amuay.

Minerals

Extraction of minerals is carried out on the continental shelves:

• sulfur (Gulf of Mexico);
• iron ore (near Newfoundland Island);
• diamonds (continental shelf of South America);
• phosphate sands and phosphorite formations (near Liberia, Morocco, Blake Plateau);
• hard coal (Canada, Great Britain).

The coastal areas are rich in zirconium, titanium, monazite, phosphorites, and amber. The largest deposits are located off the coast of the Florida Peninsula and near Brazil. In smaller quantities, these minerals are found off the coast of Uruguay, Argentina, Spain, Denmark, Portugal.

Ferruginous and tin-bearing sands are common on the Atlantic coast of Europe and North America, and deposits of gold, platinum and diamonds are found off the coast of southwestern Africa (Namibia, Angola, South Africa).

Remark 2

The extraction of phosphate rock and phosphate sand is unprofitable due to their lower quality compared to the fossils of the land.

In the northwestern regions of the ocean, on the Blake Plateau and in the North American Basin, there are vast fields of ferromanganese nodules. Their total reserves are estimated at 45 billion tons. They have a high level of concentration of non-ferrous metals.

Barite, pebbles, sand, limestone are mined from the seabed. The Atlantic countries extract magnesium, table salt, bromine, magnesium from sea water (Great Britain, France, Italy, Spain, Argentina, Canada).

ATLANTIC OCEAN(Latin name Mare Atlanticum, Greek 'Ατλαντίς - meant the space between the Strait of Gibraltar and the Canary Islands, the whole ocean was called Oceanus Occidentalis - Western approx.), the second largest ocean on Earth (after the Pacific), part World approx. Modern name first appeared in 1507 on the map of the Lorraine cartographer M. Waldseemüller.

Physico-geographical sketch

General information

In the north, the border of A. about. with the Arctic basin approx. runs east. the entrance of the Hudson Strait, then through the Davis Strait. and along the coast of about. Greenland to Cape Brewster, across the Danish Strait. to Cape Røydinupyur on the island. Iceland, along its coast to Cape Gerpir (Terpir), then to the Faroe Islands, then to the Shetland Islands and at 61 ° N. NS. to the coast of the Scandinavian Peninsula. In the east of A. about. limited by the shores of Europe and Africa, in the west - by the shores of the North. America and South. America. Border A. about. with Indian approx. is drawn along a line running from Cape Agulhas along the meridian 20 ° E. to the coast of Antarctica. Border with Tikhim approx. lead from Cape Horn along the meridian 68 ° 04 ′ W. d. or the shortest distance from the South. America to the Antarctic Peninsula across the Strait. Drake, from Fr. Oste to Cape Sternek. South part A. about. sometimes called the Atlantic sector of the South ok., drawing the border along the subantarctic zone. convergence (approximately 40 ° S lat.). In some works, the division of A. o is proposed. to the North. and Yuzh. Atlantic oceans, but it is more accepted to consider it as a single ocean. A. about. - the most biologically productive of the oceans. It contains the longest underwater ocean. ridge - Mid-atlantic ridge; the only sea that does not have solid shores, bounded by currents - Sargasso Sea; Hall. Fundy with the highest tidal wave; to the basin A. o. refers Black Sea with a unique hydrogen sulfide layer.

A. about. stretches from north to south for almost 15 thousand km, its smallest width is approx. 2830 km in the equatorial part, the largest - 6700 km (along the parallel of 30 ° N lat.). Area A. o. with seas, bays and straits 91.66 million km 2, without them - 76.97 million km 2. The volume of waters is 329.66 million km 3, without seas, bays and straits - 300.19 million km 3. Wed depth 3597 m, maximum - 8742 m (trough Puerto Rico). The most easily accessible ocean shelf zone (with depths up to 200 m) occupies approx. 5% of its area (or 8.6% if we take into account seas, bays and straits), its area is larger than in the Indian and Pacific Oceans, and much less than in the Arctic Ocean. Areas with depths from 200 m to 3000 m (continental slope zone) occupy 16.3% of the ocean area, or 20.7% taking into account the seas and bays, more than 70% - the ocean floor (abyssal zone). See map.

Seas

In the basin of A. o. - numerous. seas, which are divided: into internal - Baltic, Azov, Black, Marmara and Mediterranean (in the latter, in turn, the seas are distinguished: Adriatic, Alboran, Balearic, Ionian, Cypriot, Ligurian, Tyrrhenian, Aegean); inter-island - Irish and int. seas west. the coast of Scotland; marginal - Labrador, North, Sargassovo, Caribbean, Scotia (Scotia), Weddell, Lazarev, west. part of Riiser-Larsen (see separate articles on the seas). The largest bays of the ocean: Biscay, Bristol, Guinea, Mexican, Maine, St. Lawrence. The most important straits of the ocean: Great Belt, Bosphorus, Gibraltar, Dardanelles, Danish, Davisov, Drake, Øresund (Sound), Cabota, Kattegat, Kerch, English Channel (including Pas-de-Calais), Small Belt, Messinsky, Skagerrak , Florida, Yucatan.

Islands

In contrast to other oceans, in Africa the lake. there are few seamounts, guyots and coral reefs, and there are no coastal reefs. The total area of ​​the islands of the Atlantic Ocean. OK. 1070 thousand km 2. Main groups of islands are located on the outskirts of the continents: British (Great Britain, Ireland, etc.) - the largest in area, Greater Antilles (Cuba, Haiti, Jamaica, etc.), Newfoundland, Iceland, the Tierra del Fuego archipelago (Tierra del Fuego, Oste, Navarino) , Marajo, Sicily, Sardinia, Lesser Antilles, Falkland (Malvinas), Bahamas, etc. In the open ocean there are small islands: Azores, Sao Paulo, Ascension, Tristan da Cunha, Bouvet (on the Mid-Atlantic ridge), etc. ...

The shores

The coastline in the north. parts A. about. heavily indented (see also Coast ), almost all large inland seas and bays are located here, in the south. parts A. about. the banks are weakly indented. The shores of Greenland, Iceland and the coast of Norway preim. tectonic-glacial dissection of fjord and fiard types. Farther south, in Belgium, they give way to sandy shallow shores. Flanders coast ch. arr. arts. origin (coastal dams, polders, canals, etc.). Shore about. UK and Fr. Ireland abrasion-bay, high limestone cliffs alternate with sandy beaches and muddy drylands. On the Cotentin Peninsula there are rocky shores, sandy and gravel beaches. North. the coast of the Iberian Peninsula is composed of rock formations, to the south, off the coast of Portugal, sandy beaches prevail, often fencing off lagoons. Sandy beaches also border the shores of the West. Sahara and Mauritania. To the south of Cape Zelyoniy there are leveled abrasion-bay shores with mangrove thickets. Zap. the Cote d'Ivoire section has an accumulative coastline with rocky headlands. To the southeast, to the vast delta of the river. Niger is an accumulative coastline. the number of spits, lagoons. In the southwest. Africa - accumulative, less often abrasion-bay shores with extensive sandy beaches. The shores of southern Africa of the abrasion-bay type are composed of solid crystalline. breeds. The shores of the arctic. Canada is abrasive, with high cliffs, glacial deposits and limestones. In the east. Canada and sowing. parts of the hall. St. Lawrence, there are intensively eroded cliffs of limestone and sandstone. In the west and south, hall. St. Lawrence - wide beaches. On the shores of the Canadian provinces of Nova Scotia, Quebec, Newfoundland - outcrops of solid crystalline. rocks. From about 40 ° N. NS. to Cape Canaveral in the USA (Florida) - alternation of leveled accumulative and abrasion types of shores, composed of loose rocks. Coast of the Mexican Hall. low-lying, fringed with mangroves in Florida, sand barriers in Texas and delta shores in Louisiana. On the Yucatan Peninsula - cemented beach sediments, to the west of the peninsula - an alluvial-marine plain with coastal ramparts. On the coast of the Caribbean Sea, abrasion and accumulative areas with mangrove swamps, alongshore barriers and sandy beaches alternate. South of 10 ° N NS. accumulative banks are widespread, composed of material carried out from the mouth of the river. Amazon and other rivers. In the northeast of Brazil, there is a sandy coast with mangrove thickets, interrupted by river estuaries. From Cape Kalkanyar to 30 ° S NS. - high abrasion-type coastline. To the south (off the coast of Uruguay) there is an abrasion-type coast, composed of clays, loesses, and sand and gravel deposits. In Patagonia, the shores are represented by high (up to 200 m) cliffs with loose sediments. The shores of Antarctica are 90% composed of ice and belong to the ice and thermal abrasion type.

Bottom relief

At the bottom of A. o. distinguish the following major geomorphological. provinces: the underwater outskirts of the continents (shelf and continental slope), the ocean floor (deep-sea basins, abyssal plains, zones of abyssal hills, uplifts, mountains, deep-sea trenches), mid-ocean. ridges.

The boundary of the continental shoal (shelf) of the Atlantic Ocean. takes place on Wed. at depths of 100-200 m, its position can vary from 40-70 m (in the area of ​​Cape Hatteras and the Florida Peninsula) to 300-350 m (Weddell Cape). The shelf width ranges from 15–30 km (northeastern Brazil, Iberian Peninsula) to several hundred km (Severnoye m., Gulf of Mexico, Newfoundland Bank). In high latitudes, the relief of the shelf is complex and bears traces of glacial impact. Numerous. uplifts (banks) are separated by longitudinal and transverse valleys or trenches. Off the coast of Antarctica, ice shelves are located on the shelf. At low latitudes, the shelf surface is more leveled, especially in the zones of terrigenous material removal by rivers. It is crossed by transverse valleys, often turning into canyons of the continental slope.

The slope of the continental slope of the ocean is in Wed. 1-2 ° and varies from 1 ° (areas of Gibraltar, Shetland Islands, parts of the African coast, etc.) to 15-20 ° off the coast of France and the Bahamas. The height of the continental slope varies from 0.9–1.7 km near the Shetland Islands and Ireland to 7–8 km in the Bahamas and the Puerto Rico trench. The active margins are characterized by high seismicity. The surface of the slope is in places dissected by steps, scarps and terraces of tectonic and accumulative origin and longitudinal canyons. At the foot of the continental slope, gently sloping hills are often located. up to 300 m and shallow underwater valleys.

In the middle part of the bottom of the A. o. is the largest mountain range of the Mid-Atlantic Ridge. It extends from Fr. Iceland to about. Bouvet at 18,000 km. The width of the ridge ranges from several hundred to 1000 km. The ridge runs close to the midline of the ocean, dividing it to the east. and app. parts. On both sides of the ridge, there are deep-water basins separated by bottom uplifts. In zap. parts A. about. from north to south, there are depressions: Labrador (with depths of 3000–4000 m); Newfoundland (4200-5000 m); North American Basin(5000-7000 m), which includes the abyssal plains of Som, Hatteras and Nares; Guiana (4500-5000 m) with the plains of Demerara and Ceara; Brazilian Basin(5000–5500 m) from the abyssal plain of Pernambuco; Argentinian (5000-6000 m). In the east. parts A. about. the basins are located: Western European (up to 5000 m), Iberian (5200–5800 m), Canary (over 6000 m), Cape Verde (up to 6000 m), Sierra Leone (about 5000 m), Guinean (St. 5000 m), Angolan (up to 6000 m), Cape (over 5000 m) with the abyssal plains of the same name. In the south is the African-Antarctic Basin with the Weddell Abyssal Plain. The bottom of the deep-water basins at the foot of the Mid-Atlantic Ridge is occupied by a zone of abyssal hills. The basins are separated by the uplifts of Bermuda, Rio Grande, Rockall, Sierra Leone, and others, and by the Kitovy, Newfoundland, and other ridges.

Seamounts (isolated conical heights of 1000 m and more) at the bottom of the Atlantic Ocean. focused preim. in the area of ​​the Mid-Atlantic Ridge. In the deep-water part, large groups of seamounts are found north of Bermuda, in the Gibraltar sector, in the north-east. protrusion Yuzh. America, in the Guinean Hall. and west of the South. Africa.

Deep sea trenches of Puerto Rico, Caiman(7090 m), South Sandwich trough(8264 m) are located at the island arcs. Gutter Romanche(7856 m) is a large fault. The steepness of the slopes of the deep-water trenches is from 11 ° to 20 °. The bottom of the gutters is flat, leveled by accumulation processes.

Geological structure

A. about. arose as a result of the collapse of the Late Paleozoic supercontinent Pangea in Jurassic time. It is characterized by a sharp predominance of passive outskirts. A. about. borders adjacent continents on transform faults south of about. Newfoundland, along sowing. coast of the Gulf of Guinea., along the Falkland submarine plateau and the Agulhas plateau in the south. parts of the ocean. Active outskirts are observed at dep. areas (in the area of ​​the Lesser Antilles arc and the arc of the South Sandwich Islands), where the immersion takes place ( subduction) lithosphere A. o. The limited extent of the Gibraltar subduction zone has been identified in the Gulf of Cadiz.

In the Mid-Atlantic Ridge, the bottom is spreading ( spreading) and the formation of oceanic. bark at a rate of up to 2 cm per year. High seismicity is characteristic. and volcanic. activity. In the north of the Mid-Atlantic Ridge, paleospreading ridges branch off at Cape Labrador and into the Bay of Biscay. In the axial part of the ridge, there is a pronounced rift valley, which is absent in the extreme south and on the b. including the Reykjanes ridge. Within its limits is volcanic. uplifts, frozen lava lakes, basaltic lava flows in the form of pipes (pillow-basalts). To the Center. Fields of metal-bearing hydrotherm, many of which form hydrothermal structures at the outlet (composed of sulfides, sulfates and metal oxides); installed metalliferous sediments... At the foot of the slopes of the valley there are taluses and landslides, consisting of boulders and rubble of oceanic rocks. crust (basalt, gabbro, peridotite). The age of the crust within the Oligocene ridge is modern. The mid-Atlantic ridge divides the west. and east. abyssal plains, where oceanic. the basement is covered by a sedimentary cover, the thickness of which increases towards the continental foothills to 10–13 km due to the appearance of more ancient horizons in the section and the influx of clastic material from the land. In the same direction, the age of the oceanic. crust, reaching the Early Cretaceous (north of Florida - Middle Jurassic). The abyssal plains are practically aseismic. The mid-Atlantic ridge is crossed by numerous. transform faults extending to adjacent abyssal plains. The thickening of such faults is observed in the equatorial zone (up to 12 by 1700 km). The largest transform faults (Vima, Sao Paulo, Romansh, etc.) are accompanied by deep incisions (grooves) on the ocean floor. They reveal the entire oceanic section. crust and partly of the upper mantle; there are widespread protrusions (cold intrusions) of serpentinized peridotites, forming ridges elongated along the strike of the faults. Mn. transform faults are transoceanic, or main (demarcation) faults. In A. about. there are so-called. intraplate uplifts, represented by submarine plateaus, aseismic ridges and islands. They possess oceanic. bark of increased power and have hl. arr. volcanic origin. Many of them were formed as a result of the action mantle plumes; some arose at the intersection of the spreading ridge by large transform faults. To volcanic. uplifts include: o. Iceland, about. Bouvet, oh. Madeira, the Canary Islands, Cape Verde, Azores, the paired uplifts of the Sierra and Sierra Leone, the Rio Grande and the Whale Ridge, the Bermuda uplift, the Cameroon group of volcanoes, and others. there are intraplate uplifts of non-volcanic. nature, including the Rockall underwater plateau, separated from the British Isles of the same name. trog. The plateau is microcontinent, separated from Greenland in the Paleocene. Another microcontinent also split off from Greenland is the Hebrides Massif in northern Scotland. Submarine marginal plateaus off the coast of Newfoundland (Great Newfoundland, Flemish Cap) and off the coast of Portugal (Iberian) were cut off from the continents as a result of rifting in the late Jurassic - early Cretaceous.

A. about. divided by transoceanic transform faults into segments with different opening times. From north to south, the Labrador-British, Newfoundland-Iberian, Central, Equatorial, Southern and Antarctic segments are distinguished. The opening of the Atlantic began in the Early Jurassic (about 200 Ma ago) from the Central Segment. In the Triassic - Early Jurassic, oceanic spreading. the bottom was preceded by a continental rifting, traces of which are recorded in the form of semi-grabens filled with detrital deposits on Amer. and North - Afr. the outskirts of the ocean. In the late Jurassic - early Cretaceous, the Antarctic segment began to open. In the Early Cretaceous, spreading was tested by Yuzh. segment in the South. Atlantic and Newfoundland-Iberian segment in the North. Atlantic. Opening of the Labrador-British segment began in the late Early Cretaceous. At the end of the Late Cretaceous, the Labrador Sea basin arose here as a result of spreading on the side axis, which continued until the Late Eocene. North. and Yuzh. The Atlantic united in the middle Cretaceous - Eocene during the formation of the Equatorial segment.

Bottom sediments

The thickness of the stratum is present-day. bottom sediments range from several meters in the zone of the Mid-Atlantic Ridge to 5-10 km in the zones of transverse faults (eg, in the Romanche trench) and at the foot of the continental slope. In deep-water basins, their thickness is from several tens to 1000 m. St. 67% of the ocean floor area (from Iceland in the north to 57–58 ° S) is covered with calcareous deposits formed by the remains of shells of planktonic organisms (mainly foraminifera, coccolithophore). Their composition varies from coarse sands (at depths of up to 200 m) to silts. At depths of more than 4500–4700 m, calcareous silts are replaced by polygenic and siliceous planktonic sediments. The first ones take approx. 28.5% of the area of ​​the ocean floor, lining the bottoms of the basins, and represented red deep ocean clay(deep-sea clayey silts). These sediments contain mean. the amount of manganese (0.2–5%) and iron (5–10%) and a very small amount of carbonate material and silicon (up to 10%). Siliceous planktonic sediments occupy approx. 6.7% of the ocean floor area, of which the most widespread are diatom oozes (formed by the skeletons of diatoms). They are common off the coast of Antarctica and on the South-West shelf. Africa. Radiolarian oozes (formed by skeletons of radiolarians) are found in Ch. arr. in the Angola Basin. Terrigenous sediments of various compositions (gravel-pebble, sandy, clayey, etc.) are developed along the coast of the ocean, on the shelf and partly on the continental slopes. The composition and thickness of terrigenous sediments are determined by the bottom topography, the activity of the influx of solid material from the land and the mechanism of their transfer. Glacial precipitation carried out by icebergs is widespread along the coast of Antarctica, about. Greenland, about. Newfoundland, Labrador Peninsula; are composed of poorly sorted detrital material with the inclusion of boulders, to a greater extent in the south of the Atlantic Ocean. In the equatorial part, sediments (from coarse sand to silt) formed from pteropod shells are often found. Coral sediments (coral breccias, pebbles, sands and silts) are localized in the Gulf of Mexico, the Caribbean m. And at the northeast. the coast of Brazil; their maximum depth is 3500 m. Volcanic sediments are developed near the volcanic. islands (Iceland, Azores, Canary, Cape Verde, etc.) and are represented by fragments of volcanic. rocks, slag, pumice, volcanic. ashes. Modern chemogenic sediments are found on the Big Bahamas Bank, in the Florida-Bahamas, Antilles regions (chemogenic and chemogenic-biogenic carbonates). In the basins of the North American, Brazilian, Cape Verde, there are ferromanganese nodules; their composition in AO: manganese (12.0-21.5%), iron (9.1-25.9%), titanium (up to 2.5%), nickel, cobalt, and copper (tenths of a percent ). Phosphorite nodules appear at depths of 200–400 m in the east. coasts of the United States and north-west. coast of Africa. Phosphorites are distributed along the east. coast of A. about. - from the Iberian Peninsula to Cape Agulhas.

Climate

Due to the large extent of the A. about. its waters are located in almost all natural climates. zones - from the subarctic in the north to the Antarctic in the south. From the north and south, the ocean is wide open to the impact of the arctic. and antarctic. waters and ice. The lowest air temperature is observed in the polar regions. Over the coast of Greenland, the temperature can drop to -50 ° C, and in the south. part of Weddell Cape was recorded at -32.3 ° C. In the equatorial region, the air temperature is 24–29 ° C. The pressure field over the ocean is characterized by a successive change of stable large baric formations. Above the ice domes of Greenland and Antarctica - anticyclones, in the temperate latitudes of the North. and Yuzh. hemispheres (40-60 °) - cyclones, in lower latitudes - anticyclones, separated by a zone of low pressure at the equator. This baric structure supports the tropical. and equatorial latitudes steady east winds. directions (trade winds), in temperate latitudes - strong winds west. directions that have received the names of sailors. "Roaring forties". Strong winds are also characteristic of the Bay of Biscay. In the equatorial region, the interaction of sowing. and south. baric systems leads to frequent tropics. cyclones (tropical hurricanes), the highest activity of which is observed from July to November. The horizontal dimensions are tropical. cyclones up to several hundred km. The wind speed in them is 30–100 m / s. They move, as a rule, from east to west at a speed of 15–20 km / h and reach their greatest strength over the Caribbean Sea and the Gulf of Mexico. In areas of low pressure in temperate and equatorial latitudes, precipitation often falls and strong clouds are observed. So, at the equator falls St. 2000 mm of precipitation per year, in temperate latitudes - 1000–1500 mm. In areas of high pressure (subtropics and tropics), the amount of precipitation decreases to 500–250 mm per year, and in areas adjacent to the desert shores of Africa and in the South Atlantic maximum - to 100 mm or less per year. In areas where warm and cold currents meet, fogs are frequent, for example. in the Newfoundland Bank area and in the hall. La Plata.

Hydrological regime

Rivers and water balan with. In the basin of A. o. 19 860 km 3 of water are carried out by rivers every year, this is more than in any other ocean (about 45% of the total runoff into the World Ocean). The largest rivers (with an annual discharge of over 200 km 3): Amazon, Mississippi(flows into the Mexican Gulf.) St. Lawrence River, Congo, Niger, Danube(flows into the Black m.), Parana, Orinoco, Uruguay, Magdalena(flows into the Caribbean m.). However, the balance of fresh water in A. o. negative: evaporation from its surface (100–125 thousand km 3 / year) significantly exceeds atmospheric precipitation (74–93 thousand km 3 / year), river and underground runoff (21 thousand km 3 / year) and melting of ice and icebergs in the Arctic and Antarctic (about 3 thousand km 3 / year). The water balance deficit is replenished by the inflow of water, Ch. arr. 3470 thousand km 3 / year flows from the Pacific Ocean through the Drake Passage with the flow of the Western Winds, and from A. about. in Quiet approx. leaves only 210 thousand km 3 / year. From the Northern Arctic approx. through numerous. straits in A. about. receives 260 thousand km 3 / year and 225 thousand km 3 / year Atlantic. water flows back into the Arctic approx. Water balance with Indian approx. negative, in Indian approx. with the course of the Western Winds, 4976 thousand km 3 / year are carried out, and comes back from the Coastal Antarctic. current, deep and bottom waters only 1692 thousand km 3 / year.

Temperature mode m. Wed the temperature of ocean waters as a whole is 4.04 ° C, and surface waters are 15.45 ° C. The distribution of water temperature on the surface is asymmetric relative to the equator. Strong influence of the Antarctic. waters leads to the fact that the surface waters of the South. hemisphere is almost 6 ° C colder than the North, the warmest waters of the open part of the ocean (thermal equator) are between 5 and 10 ° C. sh., that is, shifted to the north of the geographic. equator. Features of large-scale circulation of waters lead to the fact that the temperature of water on the surface near the west. the coasts of the ocean are about 5 ° C higher than those of the east. The warmest water temperature (28–29 ° C) on the surface is in the Caribbean Sea and the Gulf of Mexico. in August, the lowest - off the coast of about. Greenland, about. Baffin's Land, Labrador Peninsula and Antarctica, south of 60 °, where even in summer the water temperature does not rise above 0 ° C. The temperature of the waters in the layer of Ch. thermocline (600–900 m) is approx. 8–9 ° C, deeper, in intermediate waters, drops to Wed. up to 5.5 ° C (1.5–2 ° C in Antarctic intermediate waters). In the deep waters, the water temperature in Wed. 2.3 ° C, in the bottom 1.6 ° C. At the very bottom, the water temperature increases slightly due to geothermal conditions. heat flow.

Salinity l. In the waters of A. o. contains approx. 1.1 × 10 16 tons of salts. Wed the salinity of the waters of the entire ocean is 34.6 ‰, of surface waters 35.3 ‰. The highest salinity (over 37.5 ‰) is observed on the surface in the subtropical. areas where evaporation of water from the surface exceeds its input with atmospheric precipitation, the smallest (6–20 ‰) is in the mouths of large rivers flowing into the ocean. From subtropics to high latitudes, salinity on the surface decreases to 32–33 ‰ under the influence of atmospheric precipitation, ice, river and surface runoff. In temperate and tropical. areas max. salinity values ​​- on the surface, an intermediate minimum salinity is observed at depths of 600–800 m. Water sowing. parts A. about. characterized by a deep maximum salinity (more than 34.9 ‰), which is formed by highly saline Mediterranean waters. Deep waters of A. o. have a salinity of 34.7–35.1 ‰ and a temperature of 2–4 ° C, bottom, occupying the deepest depressions of the ocean, 34.7–34.8 ‰ and 1.6 ° C, respectively.

Density. The density of water depends on temperature and salinity, and for A. o. temperature is of greater importance in the formation of the field of water density. The waters with the lowest density are located in the equatorial and tropical. zones with a high water temperature and a strong influence of the runoff of such rivers as the Amazon, Niger, Congo and others (1021.0-1022.5 kg / m 3). To the south. in parts of the ocean, the density of surface waters increases to 1025.0–1027.7 kg / m 3, in the northern - to 1027.0–1027.8 kg / m 3. Density of deep waters of the Atlantic Ocean. 1027.8-1027.9 kg / m 3.

Ice mode m. In sowing. parts A. about. annual ice is formed by hl. arr. in int. seas of temperate latitudes, perennial ice is carried out from the Arctic approx. The boundary of the distribution of the ice cover in the north. parts A. about. changes significantly, in winter, pack ice can reach decomp. years 50–55 ° N NS. There is no ice in the summer. The border of the Antarctic. perennial ice in winter it passes at a distance of 1600–1800 km from the coast (approximately 55 ° S lat.), in summer (in February – March) ice occurs only in the coastal strip of Antarctica and in Weddell Cape. Main iceberg suppliers - ice sheets and ice shelves of Greenland and Antarctica. The total mass of icebergs arriving from the Antarctic. glaciers, estimated at 1.6 × 10 12 tons per year, main. their source is the Filchner Ice Shelf at Cape Weddell. From the glaciers of the Arctic to A. about. icebergs with a total mass of 0.2–0.3 × 10 12 tons per year are received, in the main. from the Jacobshavn glacier (in the area of ​​Disko Island off the western coast of Greenland). Wed life expectancy arctic. icebergs approx. 4 years old, slightly more Antarctic. The boundary of the distribution of icebergs in the north. parts of the ocean 40 ° N sh., but in dep. cases they were observed up to 31 ° N. NS. To the south. part of the border runs at 40 ° S. sh., to the center. parts of the ocean and at 35 ° S. NS. on app. and east. periphery.

The currents are I. Water circulation A. o. subdivided into 8 quasi-stationary oceanic. gyres located almost symmetrically relative to the equator. From low to high latitudes in North. and Yuzh. hemispheres are tropical. anticyclonic, tropical cyclonic, subtropical anticyclonic, subpolar cyclonic oceanic gyres. Their boundaries, as a rule, are Ch. oceanic currents. A warm current begins near the Florida Peninsula Gulf Stream... Absorbing warm waters Antilles current and Florida current, The Gulf Stream heads northeast and splits into several branches at high latitudes; the most significant of them - Irminger's current, which transports warm waters to the Davis Strait, the North Atlantic Current, Norwegian current, going to the Norwegian m. and further to the northeast, along the coast of the Scandinavian Peninsula. To meet them from Davisov Strait. comes out cold Labrador current, the waters of which can be traced off the coast of America up to almost 30 ° C. NS. From the Danish Strait. the cold East Greenland current goes into the ocean. In the low latitudes of the Atlantic Ocean. warm Northern trade winds and Southern trade winds, between them, approximately 10 ° N. sh., from west to east there is an inter-trade countercurrent, which is active ch. arr. in the summer in North. hemisphere. Separates from the South trade winds Brazilian current, which runs from the equator and up to 40 ° S. NS. along the shores of America. North. a branch of the South trade wind currents forms Guiana current, which is directed from the south to the north-west before joining the waters of the North trade wind currents. Off the coast of Africa from 20 ° N. NS. the warm Guinean current passes up to the equator; in the summertime, the Inter-trade countercurrent is connected to it. To the south. parts A. about. crosses the cold West Winds current(Antarctic circumpolar current), which is part of the Atlantic Ocean. across the strait Drake, descends to 40 ° S. NS. and goes to the Indian approx. south of Africa. The Falkland Current is separated from it, reaching along the coast of America almost to the mouth of the river. Parana, Benguela Current, which runs along the coast of Africa almost to the equator. Cold Canary current runs from north to south - from the shores of the Iberian Peninsula to the Cape Verde Islands, where it passes into the North trade winds.

Deep circulation in Deep circulation and structure of the waters of the Atlantic Ocean. are formed as a result of changes in their density during cooling of waters or in zones of mixing of waters decomp. origin, where the density increases as a result of mixing waters with decomp. salinity and temperature. Subsurface waters are formed in the subtropical. latitudes and occupy a layer with a depth of 100–150 m to 400–500 m, with a temperature of 10 to 22 ° C and a salinity of 34.8–36.0 ‰. Intermediate waters are formed in subpolar regions and are located at depths from 400–500 m to 1000–1500 m, with a temperature of 3 to 7 ° C and a salinity of 34.0–34.9 ‰. The circulation of subsurface and intermediate waters is generally anticyclonic. character. Deep waters are formed in high latitudes of sowing. and south. parts of the ocean. The waters formed in the Antarctic. area, have the highest density and spread from south to north in the bottom layer, their temperature varies from negative (in high southern latitudes) to 2.5 ° C, salinity 34.64–34.89 ‰. The waters formed in high sowing. latitudes, move from north to south in a layer from 1500 to 3500 m, the temperature of these waters is from 2.5 to 3 ° C, salinity is 34.71–34.99 ‰. In the 1970s. VN Stepanov and, later, VS Broker substantiated the scheme of planetary interoceanic transfer of energy and matter, which received the name. “Global conveyor” or “global thermohaline circulation of the World Ocean”. According to this theory, the relatively salty North Atlantic. waters reach the coast of Antarctica, mix with supercooled shelf water and, passing through the Indian ok., finish their way to the north. parts of the Pacific Ocean.

Tides and waves e. Tides in A. o. preim. semi-daily. The height of the tidal wave: 0.2–0.6 m in the open part of the ocean, a few cm in the Black m., 18 m in the bay. Fundy (North of the Bay of Maine in North America) is the highest in the world. The height of wind waves depends on the speed, time of impact and acceleration of the wind; during strong storms it can reach 17–18 m. Rarely enough (once every 15–20 years), waves of high. 22-26 m.

Flora and fauna

The great extent of the Atlantic Ocean, the variety of climatic conditions. conditions, then. inflow of fresh water and large upwellings provide a variety of living conditions. In total, approx. 200 thousand species of plants and animals (of which about 15,000 species of fish, about 600 species of cephalopods, about 100 species of whales and pinnipeds). Life is very unevenly distributed in the ocean. There are three mains. the type of zoning of the distribution of life in the ocean: latitudinal, or climatic, vertical and circumcontinental. The density of life and its species diversity decrease with distance from the coast towards the open ocean and from the surface to deep waters. Species diversity decreases from tropical. latitudes to high.

Planktonic organisms (phytoplankton and zooplankton) are the backbone of the food chain in the ocean. their mass lives in the upper zone of the ocean, where light penetrates. The greatest biomass of plankton is in high and temperate latitudes during spring-summer flowering (1–4 g / m 3). During the year, the biomass can change by a factor of 10–100. Main phytoplankton species - diatoms, zooplankton - copepods and euphausids (up to 90%), as well as bristle-mandibular, hydromedusa, comb jellies (in the north) and salps (in the south). In low latitudes, the plankton biomass varies from 0.001 g / m 3 in the anticyclonic centers. gyres up to 0.3–0.5 g / m 3 in the Gulfs of Mexico and Guinea. Phytoplankton is represented by Ch. arr. coccolithins and peridineas, the latter can develop in coastal waters in huge quantities, causing catastrophic. the phenomenon of "red tide". Zooplankton at low latitudes is represented by copepods, chaetomaxillary, hyperids, hydromedusae, siphonophores, and other species. There are no clearly pronounced dominant species of zooplankton at low latitudes.

Benthos is represented by large algae (macrophytes), which b. h. grow at the bottom of the shelf zone to a depth of 100 m and cover approx. 2% of the total area of ​​the ocean floor. The development of phytobenthos is observed in those places where there are suitable conditions — soils suitable for anchoring to the bottom, the absence or moderate velocities of bottom currents, etc. In the high latitudes of the Atlantic Ocean. main part of the phytobenthos are kelp and red algae. In the temperate zone, sowing. parts of the Atlantic Ocean, along the American and European coasts, are brown algae (fucus and ascophyllum), kelp, desmarestia, and red algae (furcellaria, anfeltia, etc.). Zostera is common on soft soils. In the temperate and cold zones of the south. parts A. about. brown algae prevail. To the tropical. In the littoral zone, due to strong heating and intense insolation, vegetation on the ground is practically absent. A special place is occupied by the ecosystem of Sargassov m., Where floating macrophytes (mainly three species of algae of the genus Sargassum) form clusters on the surface in the form of ribbons from 100 m to several. kilometers.

The biomass of nekton (actively swimming animals — fish, cephalopods, and mammals) are fish. The largest number of species (75%) lives in the shelf zone, with depth and distance from the coast, the number of species decreases. For cold and temperate zones are characteristic: from fish - decomp. species of cod, haddock, pollock, herring, flounder, catfish, conger eel, etc., herring and polar sharks; mammals - pinnipeds (harp seal, hooded seal, etc.), decomp. species of cetaceans (whales, sperm whales, killer whales, grinds, bottlenose, etc.).

There is a great deal of similarity between the faunas of the temperate and high latitudes of both hemispheres. At least 100 species of animals are bipolar, that is, they are characteristic of both temperate and high belts. For tropical. zone A. o. typical: fish - decomp. sharks, flying fish, sailboats, decomp. types of tuna and glowing anchovies; from animals - sea turtles, sperm whales, river dolphin inia; cephalopods are also numerous - decomp. species of squid, octopus, etc.

Deep-sea fauna (zoobenthos) represented by sponges, corals, echinoderms, crustaceans, molluscs, decomp. worms.

Research history

There are three stages in the study of A. o. The first is characterized by the establishment of the boundaries of the ocean and the discovery of its individual objects. AT 12- 5th c. BC NS. Phoenicians, Carthaginians, Greeks and Romans left descriptions of sea voyages and the first nautical charts. Their voyages reached the Iberian Peninsula, England and the mouth of the Elbe. In the 4th century. BC NS.Piteas(Pytheas) while sailing in the North. Atlantic determined the coordinates of a number of points and described the tidal phenomena in the Atlantic Ocean. By the 1st century. n. NS. mentions of the Canary Islands belong. In the 9-10th centuries. Normans (RaudiEirik and his son Leif Eirikson) crossed the ocean, visited Iceland, Greenland, Newfoundland and explored the shores of the North. America under 40° N NS. In the eraGreat geographical discoveries(mid-15th - mid-17th centuries) navigators (mainly Portuguese and Spaniards) are mastering the way to India and China along the coast of Africa. The most outstanding voyages during this period were made by the Portuguese B.Diashem(1487), by the Genoese H.Columbus(1492-1503), by the Englishman J.Cabot(1497) and the Portuguese Vasco daGama(1498); for the first time trying to measure the depths of the open parts of the ocean and the speed of surface currents. First bathymetric map (depth map) A. o. was compiled in Spain in 1523. In 1520 F.Magellanfirst passed from A. about. in Quiet approx. the strait, later named after him. In the 16-17 centuries. the Atlantic is being intensively researched. coast of the North. America (British J.Davis, 1576–78, G. Hudson, 1610, W. Buffin, 1616, and other navigators, whose names can be found on the map of the ocean). In 1591–92 the Falkland Islands were discovered. South shores of A. o. - the mainland Antarctica - were discovered and described for the first time Rus. antarctic expedition F.F.Bellingshausen and M.P. Lazarevain 1819-21. This completed the study of the boundaries of the ocean.

The second stage is characterized by the study of physical. properties of ocean waters, temperature, salinity, currents, etc. In 1749, the Englishman G. Ellis carried out the first measurements of temperature at various depths, repeated by the Englishman J. Cook(1772), Swiss O. Saussure(1780), Russian. I. F. Kruzenshtern(1803) and others. A. about. becomes a testing ground for developing new methods of studying depths, new technology and new approaches to the organization of work. For the first time, bathometers, deep-sea thermometers, thermo-depth meters, deep-water trawls and dredges are used. Of the most significant expeditions, Rus. navigation on ships "Rurik" (1815-18) and "Enterprise" (1823–26) under the leadership of O. E.Kotzebue(1815-18); English on "Erebus" and "Terror" under the leadership of J.K.Ross(1840–43); amer. on the "Arctic" under the leadership of M.F.Morey(1856). Real integrated oceanographic ocean exploration began with an expedition in English. corvette« Challenger ”directed by W. Thomson (1872–76). Significant expeditions that followed her were carried out on the ships Gazelle (1874–76), Vityaz (1886–89), Valdivia (1898–99), Gauss (1901–03). From 1885 to 1922 he made a great contribution to the study of A. o. introduces Prince Albert I of Monaco, who organized and headed the expeditionary research on the yachts "Irendel", "Princess Alice", "Irendel II", "Princess Alice II" in the north. parts of the ocean. In the same years, he organized the Oceanographic Museum in Monaco. In 1903, work began on the "standard" sections in the North Atlantic under the leadership of the International Council for the Study of the Sea (ICES) - the first international oceanographic. scientific organization that existed before the 1st World War.

The most significant expeditions in the period between the world wars were carried out on the ships Meteor, Discovery II, Atlantis. In 1931, the International Council of Scientific Unions (ICSU) was formed, operating to the present day, organizing and coordinating ocean research.

After World War II, an echo sounder was widely used to study the ocean floor. This allowed us to get a real picture of the topography of the ocean floor. In the 1950s and 70s. comprehensive geophysical studies were carried out. and geological research A. about. and the features of the relief of its bottom and tectonics, the structure of the sedimentary strata were established. Many large forms of bottom topography (underwater ridges, mountains, troughs, fault zones, vast basins and uplifts) have been identified, and geomorphological studies have been compiled. and tectonic. cards. Unique results were obtained under the IODP international deep-sea drilling program (1961–2015, ongoing).

The third stage of ocean research is mainly aimed at studying its role in the global processes of the transfer of matter and energy, and its influence on the formation of the climate. The complexity and wide range of research work required extensive international cooperation. An important role in the coordination and organization of international research is played by the Scientific Committee for Oceanic Research (SCOR), formed in 1957, the Intergovernmental Oceanographic Commission of UNESCO (IOC), operating since 1960, and other international organizations. In 1957–58, extensive work was carried out within the framework of the first International Geophysical Year (IGY). Subsequently, large international projects were aimed at studying individual parts of the archaeological community, for example, EQUALANT I – III (1963–64), Polygon-70 (1970), CICAR (1970–75), POLYMODE (1977–78 ) and A. o. as part of the World Ocean, for example TOGA (1985–89), GEOSECS (1973–74), WOCE (1990–96), etc. In the course of these projects, the features of water circulation of various scales, distribution and composition of suspended matter were investigated; the role of the ocean in the global carbon cycle, and more. other questions. In the end. 1980s owls. deep-sea vehicles"Peace» studied the unique ecosystems of the geothermal regions of the rift zone of the ocean. If at the beginning. 80s it was ok. 20 international ocean research projects, then by the 21st century. St. 100. The largest programs:« International Geosphere-Biosphere Program» (since 1986, 77 countries participate), it includes projects« Dynamics of global oceanic ecosystems» (GLOBES, 1995–2010), "Global Fluxes of Matter in the Ocean» (JGOFS, 1988-2003), " Land-ocean interaction in the coastal zone» (LOICZ), Integrated Research on Marine Biogeochemistry and Ecosystems (IMBER), Land-Ocean Interaction in the Coastal Zone (LOICZ, 1993–2015), Investigation of Ocean Surface-Lower Atmosphere Interaction (SOLAS, 2004–15, ongoing),« World Climate Research Program» (WCRP, since 1980, 50 countries participate), International study of biogeochemical cycles and large-scale distribution of trace elements and their isotopes in the marine environment (GEOTRACES, 2006–15, ongoing) and many others. etc. The Global Ocean Observing System (GOOS) is being developed. One of the main projects of the WCRP was the Climate and Ocean Program: Instability, Predictability and Variability (CLIVAR, since 1995), based on the results of TOGA and WOCE. Grew up. For many years, scientists have been conducting expeditionary studies of exchange processes on the frontier of the Atlantic Ocean. and the Arctic c., circulation in the Drake Passage, the spread of cold Antarctic waters along deep-sea faults. Since 2005, the international program "ARGO" has been in operation, in which observations are carried out by autonomous sounding instruments throughout the entire World Ocean (including the oceanic ocean), and the results are transmitted via artificial earth satellites to data centers.

In November 2015 from Kronstadt to the shores of Antarctica, for the first time in the past 30 years, a growing was made. research vessel of the Baltic Fleet "Admiral Vladimirsky". It made a transition over 34 thousand nautical miles. miles. On the route, hydrographic, hydrological, hydrometeorological and radio navigation studies were carried out, information was collected for updating nautical navigational charts, manuals and aids for navigation. Having rounded the southern tip of the African continent, the ship entered the marginal seas of Antarctica. He moored near the dew. station "Progress", scientists exchanged data with the staff of the station on the observation of ice conditions, melting of Arctic ice, weather. The expedition ended on 15.4.2016. In addition to the crew, the expedition was attended by hydrographic specialists of the 6th Atlantic Oceanographic. expedition hydrographic. services of the Baltic Fleet, employees of Ros. state hydrometeorological University, Institute of the Arctic and Antarctic, and others. Completed work on the creation of the third part of the Oceanographic Atlas WOCE (The World Ocean Circulation Experiment), dedicated to the Atlantic Ocean, the presentation of which took place in February 2015 at the IO RAS. P.P. Shirshova.

Economic use

A. about. occupies the most important place in the world economy among other oceans of our planet. Human use of A. o., Like other seas and oceans, is based on several principles. directions: transport and communications, fishing, mining miner. resources, energy, recreation.

Transport

Already for 5 centuries A. about. takes a leading role in shipping. With the opening of the Suez (1869) and Panama (1914) canals, short sea routes appeared between the Atlantic, Indian and Pacific oceans. To the share of A. about. accounted for approx. 3/5 of the world's shipping turnover, in con. 20th century up to 3.5 billion tons of cargo was transported across its water area (according to IOC data). OK. 1/2 of the traffic volume is oil, gas and oil products, followed by general cargo, then iron ore, grain, coal, bauxite and alumina. Ch. the direction of traffic is North Atlantic, which runs between 35-40 ° N. NS. and 55-60 ° N. NS. Main shipping routes connect port cities in Europe, the USA (New York, Philadelphia) and Canada (Montreal). This direction is adjacent to the sea routes of the Norwegian, North and internal. seas of Europe (Baltic, Mediterranean and Black). Are transported in the main. raw materials (coal, ores, cotton, timber, etc.) and general cargo. Dr. important directions of transportation - South Atlantic: Europe - Central (Panama, etc.) and South America (Rio de Janeiro, Buenos Aires); east-atlantic: Europe - southern Africa (Cape Town); West-Atlantic: North. America, South America is the south of Africa. Before the reconstruction of the Suez Canal (1981) b. including oil tankers from the Indian basin approx. was forced to walk around Africa.

The carriage of passengers occupies an important place in A. about. from the 19th century, when mass emigration from the Old World to America began. The first steam-sailing vessel "Savannah" crossed the Atlantic Ocean. for 29 days in 1819. At the beginning. 19th century established the Blue Ribbon prize for passenger ships that cross the ocean the fastest. This prize was awarded, for example, to such famous liners as "Lusitania" (4 days and 11 hours), "Normandy" (4 days and 3 hours), "Queen Mary" (4 days without 3 minutes). The last time the "Blue Ribbon" was assigned to Amer. liner "United States" in 1952 (3 days and 10 hours). In the beginning. 21 c. the duration of a passenger liner flight between London and New York is 5–6 days. Max. passenger transportation through A. about. fell on 1956–57, when more than 1 million people were transported a year, in 1958 the volume of passenger traffic by air was equal to sea transport, and then everything b. of passengers gives preference to air transport (record time of flight of the supersonic liner "Concorde" on the route New York - London - 2 hours 54 minutes). The first non-stop flight across the Atlantic Ocean. committed 14-15.6.1919 English. pilots J. Alcock and A. W. Brown (Newfoundland Island - Ireland Island), the first non-stop flight across the Atlantic Ocean. alone (from continent to continent) 20-21 May 1927 - Amer. pilot C. Lindbergh (New York - Paris). In the beginning. 21 c. practically the entire flow of passengers through A. about. serviced by aviation.

Connection

In 1858, when there was no radio communication between the continents, through the Atlantic Ocean. the first telegraph cable was laid. To the end. 19th century 14 telegraph cables connected Europe with America and 1 with Cuba. In 1956, the first telephone cable was laid between the continents, by the mid-1990s. at the bottom of the ocean St. 10 telephone lines. In 1988, the first transatlantic fiber-optic communication line was laid, at the beginning of the 21st century. there are 8 lines.

Fishing

A. about. is considered the most productive ocean, its biological. resources are exploited most intensively by man. In A. about. fishing and seafood production account for 40–45% of the total world catch (area approx. 25% of the world approx.). The main part of the catch (up to 70%) is made up of herring fish (herring, sardines, etc.), cod fish (cod, haddock, hake, whiting, pollock, navaga, etc.), flounder, halibut, and sea bass. Mining of molluscs (oysters, mussels, squid, etc.) and crustaceans (lobsters, crabs) approx. eight%. According to FAO estimates, the annual catch of fish products in A. o. is 85–90 million tons, but for most of the fishery areas of the Atlantic, the fish catch reached mid. 1990s its maximum and its increase is undesirable. The traditional and most productive fishing area is northeast. part of the Atlantic Ocean, including the North and Baltic Seas (mainly herring, cod, flounder, sprats, and mackerel). In the north-west. In the ocean area, on the Newfoundland banks, cod, herring, flounder, squid, etc. have been caught for many centuries. To the center. parts A. about. there is a catch of sardines, horse mackerel, mackerel, tuna, etc. , notothenia, toothfish, etc.). Off the coast of the west. and southwest. African catch of sardines, anchovy and hake. In Antarctic in the ocean region, planktonic crustaceans (krill), marine mammals, and from fish - notothenia, toothfish, silverfish, etc. are of commercial importance. 20th century in high latitude sowing. and south. areas of the ocean were actively fished for decomp. species of pinnipeds and cetaceans, but in recent decades it has sharply decreased due to depletion of biological. resources and thanks to environmental protection measures, including intergovernmental ones. agreements on limiting their production.

Mineral resources

The miner is being developed more and more actively. wealth of the ocean floor. The deposits of oil and combustible gas have been studied more fully; the first mention of their exploitation in the basin of the Atlantic Ocean. refer to 1917, when oil production began in the industrial. scales in east. parts of the Maracaibo lagoon (Venezuela). The largest centers of offshore production: Gulf of Venezuela, Maracaibo lagoon ( Maracaiba oil and gas basin), Mexican Hall. ( Gulf of Mexico oil and gas basin), Hall. Pariah ( Orinoksky oil and gas basin), Brazilian shelf (Sergipe-Alagoas oil and gas basin), Gulf of Guinea. ( Gulf of Guinea oil and gas basin), North m. ( North Sea oil and gas region) and others. Placer deposits of heavy minerals are widespread near many coasts. The largest development of placer deposits of ilmenite, monocyte, zircon, rutile is carried out off the coast of Florida. Similar deposits are located in the Gulf of Mexico, at the east. coasts of the United States, as well as Brazil, Uruguay, Argentina and the Falkland Islands. On the shelf south-west. In Africa, offshore diamond deposits are being developed. Gold-bearing placers were discovered off the coast of Nova Scotia at depths of 25–45 m. In A. about. explored one of the world's largest iron ore deposits - Wabana (in Conception Bay off the coast of Newfoundland), iron ore is also mined off the coast of Finland, Norway and France. In the coastal waters of Great Britain and Canada, coal deposits are being developed, it is mined in mines located on land, the horizontal workings of which go under the seabed. On the shelf of the Mexican Hall. large sulfur deposits are being developed Gulf of Mexico sulfur province... In the coastal zone of the ocean, sand is mined for construction and the production of glass, gravel. On the shelf east. the coast of the United States and west. phosphorite-bearing sediments have been explored on the coast of Africa, but their development is still unprofitable. The total mass of phosphorites on the continental shelf is estimated at 300 billion tons. Large fields of ferromanganese nodules have been found at the bottom of the North American Basin and on the Blake Plateau. are estimated at 45 billion tons.

Recreational resources

From the 2nd floor. 20th century of great importance for the economies of coastal countries is the use of the recreational resources of the ocean. Old resorts are developing and new ones are being built. Since the 1970s. ocean liners intended only for carrying out cruises are being laid, they are distinguished by their large size (displacement of 70 thousand tons and more), an increased level of comfort and relative slowness. Main cruise liner routes A. o. - Mediterranean and Caribbean Seas and the Mexican Hall. From the end. 20 - early. 21 centuries scientific-tourist and extreme cruise routes are being developed, mainly in the high latitudes of the North. and Yuzh. hemispheres. In addition to the Mediterranean and Black Sea basins, the main resort centers are located in the Canary, Azores, Bermuda Islands, in the Caribbean and the Mexican Hall.

Energy

The energy of sea tides of A. o. is estimated at about 250 million kW. In the Middle Ages, tidal wave mills and sawmills were built in England and France. At the mouth of the river. Rance (France) operates a tidal power plant. The use of hydrothermal energy of the ocean (the difference in temperature in surface and deep waters) is also considered promising; a hydrothermal station operates on the coast of Cote d'Ivoire.

Port cities

On the shores of A. about. most of the major ports in the world are located: in Western Europe - Rotterdam, Marseille, Antwerp, London, Liverpool, Genoa, Le Havre, Hamburg, Augusta, Southampton, Wilhelmshaven, Trieste, Dunkirk, Bremen, Venice, Gothenburg, Amsterdam, Naples, Nantes-Saint- Nazer, Copenhagen; all in. America - New York, Houston, Philadelphia, Baltimore, Norfolk - Newport, Montreal, Boston, New Orleans; in Yuzh. America - Maracaibo, Rio de Janeiro, Santos, Buenos Aires; in Africa - Dakar, Abidjan, Cape Town. Grew up. port cities do not have direct access to the Atlantic Ocean. and are located on the banks of the ext. seas related to its basin: St. Petersburg, Kaliningrad, Baltiysk (Baltic Sea), Novorossiysk, Tuapse (Black Sea).

Some areas of the Atlantic shelf are rich in coal. The largest undersea coal mining is carried out by Great Britain. The largest exploited North Tumbberland-Derham field with reserves of about 550 million tons is located on the north-east coast of England. Explored coal deposits in the shelf zone northeast of Cape Breton Island. However, in the economy, underwater coal is of less importance than offshore oil and gas fields. The main supplier of monazite to the world market is Brazil. The USA is also the leading producer of ilmenite, rutile and zircon concentrates (placers of these metals are almost ubiquitous on the shelf of North America - from California to Alaska). Placers of cassiterite off the coast of Australia, off the Cornwall Peninsula (Great Britain), and Brittany (France) are of considerable interest. The largest accumulations of ferruginous sands in terms of reserves are located in Canada. Ferruginous sands are also mined in New Zealand. Placer gold in coastal marine sediments has been found on the western shores of the United States and Canada.

The main deposits of coastal-marine diamond-bearing sands are concentrated on the southwestern coast of Africa, where they are confined to the deposits of terraces, beaches and shelf to depths of 120 m. Significant marine terraced diamond deposits are located in Namibia. African coastal-sea placers are promising.

Underwater deposits of iron ore are located in the coastal shelf zone. The most significant development of offshore iron ore deposits is in Canada, on the east coast of Newfoundland (Wabana deposit). In addition, Canada mines iron ore in the Hudson Bay.

Copper and nickel are mined in small quantities from underwater mines (Canada - in the Hudson Bay). Tin is mined on the Cornwall Peninsula (England). In Turkey, on the coast of the Aegean Sea, mercury ores are being mined. Sweden extracts iron, copper, zinc, lead, gold and silver in the bowels of the Gulf of Bothnia.

Large salt sedimentary basins in the form of salt domes or stratal deposits are often found on the shelf, slope, foot of continents and in deep-water basins (Gulf of Mexico, shelves and slopes of western Africa, Europe). Mineral resources of these basins are represented by sodium, potassium and magnesite salts, gypsum. Calculation of these reserves is difficult: the volume of potash salts alone is estimated to range from hundreds of millions of tons to 2 billion tons. There are two salt domes in operation in the Gulf of Mexico off the coast of Louisiana.

More than 2 million tons of sulfur are extracted from underwater deposits. The largest sulfur accumulation, Grand Isle, is in operation, located 10 miles off the coast of Louisiana. Commercial reserves of phosphorites have been found near the Californian and Mexican coasts, along the coastal zones of South Africa, Argentina, and off the coast of New Zealand. Phosphorites are mined in the California region from depths of 80-330 m, where the average concentration is 75 kg / m3.

A large number of offshore oil and gas fields have been identified in the Atlantic Ocean and its seas, including those with one of the highest production levels for these fuels in the world. They are located in different areas of the ocean shelf zone. In its western part, the bowels of the Maracaibo lagoon are distinguished by very large reserves and production volumes. Oil is extracted here from more than 4500 wells, from which 93 million tons of "black gold" were obtained in 2006. The Gulf of Mexico is considered to be one of the richest offshore oil and gas regions in the world, believing that at present only a small part of the potential oil and gas reserves has been discovered in it. 14,500 wells have been drilled at the bottom of the bay. In 2011, 60 million tons of oil and 120 billion cubic meters of gas were produced from 270 offshore fields, and in total, 590 million tons of oil and 679 billion cubic meters of gas were extracted here. The most significant of them are located off the coast of the Paraguano Peninsula, in the Gulf of Paria and the island of Trinidad. Oil reserves here are estimated at tens of millions of tons.

In addition to these areas, three large oil and gas provinces are traced in the western Atlantic. One of them stretches from the Davis Strait to the latitude of New York. Within its limits, commercial oil reserves have been discovered so far near Labrador and south of Newfoundland. The second oil and gas province stretches along the coast of Brazil from Cape Kalkanyar in the north to Rio de Janeiro in the south. 25 deposits have already been discovered here. The third province occupies the coastal areas of Argentina from the Gulf of São Jorge to the Strait of Magellan. Only small deposits have been discovered in it, which are not yet profitable for offshore development.

In the shelf zone of the east coast of the Atlantic, oil shows were found south of Scotland and Ireland, off the coast of Portugal, in the Bay of Biscay. A large oil and gas region is located near the African continent. About 8 million tons are produced by the oil fields concentrated near Angola.

Very significant resources of oil and gas are concentrated in the bowels of some seas of the Atlantic Ocean. Among them, the most important place is occupied by the North Sea, which is unmatched in terms of the rate of development of subsea oil and gas fields. Significant subsea deposits of oil and gas have been explored in the Mediterranean Sea, where 10 oil and 17 offshore gas fields are currently operating. Significant volumes of oil are extracted from fields located off the coasts of Greece and Tunisia. The gas is being developed in the Gulf of Sidra (Bol. Sirte, Libya), off the Italian coast of the Adriatic Sea. In the future, the subsoil of the Mediterranean should yield at least 20 million tons of oil per year.