ATLANTIC OCEAN (Latin name Mare Atlanticum, Greek? τλαντ?ς - denoted the space between the Strait of Gibraltar and the Canary Islands, the whole ocean was called Oceanus Occidental is - Western Ocean), the second largest ocean on Earth (after the Pacific Ocean), part of the World Ocean. The modern name first appeared in 1507 on the map of the Lorraine cartographer M. Waldseemüller.

Physico-geographical essay. General information. In the north, the border of the Atlantic Ocean with the Arctic Ocean basin runs along the eastern entrance of the Hudson Strait, then through the Davis Strait and along the coast of Greenland Island to Cape Brewster, through the Denmark Strait to Cape Reidinupur on the island of Iceland, along its coast to Cape Gerpir (Terpire), then to the Faroe Islands, then to the Shetland Islands and along 61 ° north latitude to the coast of the Scandinavian Peninsula. In the east, the Atlantic Ocean is bounded by the shores of Europe and Africa, in the west by the shores of North America and South America. The border of the Atlantic Ocean with the Indian Ocean is drawn along the line passing from Cape Agulhas along the meridian of 20 ° east longitude to the coast of Antarctica. The border with the Pacific Ocean is drawn from Cape Horn along the meridian of 68°04' west longitude or along the shortest distance from South America to the Antarctic Peninsula through the Drake Passage, from Oste Island to Cape Sternek. The southern part of the Atlantic Ocean is sometimes called the Atlantic sector of the Southern Ocean, drawing the boundary along the subantarctic convergence zone (approximately 40 ° south latitude). Some papers propose the division of the Atlantic Ocean into the North and South Atlantic Oceans, but it is more common to consider it as a single ocean. The Atlantic Ocean is the most biologically productive of the oceans. It contains the longest underwater oceanic ridge - the Mid-Atlantic Ridge, the only sea that does not have solid shores, limited by currents - the Sargasso Sea; the Bay of Fundy with the highest tidal wave; The Black Sea with a unique hydrogen sulfide layer belongs to the Atlantic Ocean basin.

The Atlantic Ocean stretches from north to south for almost 15 thousand km, its smallest width is about 2830 km in the equatorial part, the largest is 6700 km (along the parallel of 30 ° north latitude). The area of ​​the Atlantic Ocean with seas, bays and straits is 91.66 million km 2, without them - 76.97 million km 2. The volume of water is 329.66 million km 3, without seas, bays and straits - 300.19 million km 3. The average depth is 3597 m, the greatest is 8742 m (Puerto Rico Trench). The most easily accessible for development shelf zone of the ocean (with depths up to 200 m) occupies about 5% of its area (or 8.6%, if we take into account the 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 the Atlantic Ocean there are 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) ; interisland - Irish and inland seas of the western coast of Scotland; marginal - Labrador, Northern, Sargasso, Caribbean, Scotia (Scotia), Weddell, Lazareva, the western part of Riiser-Larsen (see separate articles about the seas). The largest bays of the ocean: Biscay, Bristol, Guinean, Mexican, Maine, St. Lawrence.

Islands. Unlike other oceans, there are few seamounts, guyots and coral reefs in the Atlantic Ocean, and there are no coastal reefs. The total area of ​​the islands of the Atlantic Ocean is about 1070 thousand km2. The 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 (Land of Fire, Oste, Navarino ), Marajo, Sicily, Sardinia, Lesser Antilles, Falkland (Malvinas), Bahamas, etc. Small islands are found in the open ocean: Azores, Sao Paulo, Ascension, Tristan da Cunha, Bouvet (on the Mid-Atlantic Ridge) and others

coast. The coastline in the northern part of the Atlantic Ocean is strongly indented (see also the article Coast), almost all major inland seas and bays are located here, in the southern part of the Atlantic Ocean the coasts are slightly indented. The coasts of Greenland, Iceland and the coast of Norway are predominantly tectonic-glacial dissection of the fjord and fiard types. To the south, in Belgium, they give way to sandy shallow shores. The coast of Flanders is mainly of artificial origin (coastal dams, polders, canals, etc.). The shores of the island of Great Britain and the island of Ireland are abrasion-bay, high limestone cliffs alternate with sandy beaches and muddy lands. The Cherbourg Peninsula has rocky shores, sandy and gravel beaches. The northern coast of the Iberian Peninsula is composed of rocks, to the south, off the coast of Portugal, sandy beaches predominate, often fencing off lagoons. Sandy beaches also border the shores of Western Sahara and Mauritania. To the south of Cape Zeleny there are leveled abrasion-bay shores with mangrove thickets. The western section of Côte d'Ivoire has an accumulative

coast with rocky capes. To the southeast, to the vast delta of the Niger River, there is an accumulative coast with a significant number of spits and lagoons. In southwestern Africa - accumulative, less often abrasion-bay shores with extensive sandy beaches. The coasts of southern Africa of the abrasion-bay type are composed of solid crystalline rocks. The coasts of Arctic Canada are abrasive, with high cliffs, glacial deposits and limestones. In eastern Canada and the northern part of the Gulf of St. Lawrence, there are intensely eroded limestone and sandstone cliffs. In the west and south of the Gulf of St. Lawrence - wide beaches. On the shores of the Canadian provinces of Nova Scotia, Quebec, Newfoundland, there are outcrops of solid crystalline rocks. Approximately from 40 ° north latitude to Cape Canaveral in the USA (Florida) - alternation of leveled accumulative and abrasion types of coasts, composed of loose rocks. The Gulf Coast is low-lying, bordered by 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 ridges. On the coast of the Caribbean Sea, abrasion and accumulative areas alternate with mangrove swamps, alongshore barriers and sandy beaches. To the south of 10° north latitude, accumulative banks are widespread, composed of material carried from the mouth of the Amazon River and other rivers. In the northeast of Brazil - a sandy coast with mangroves, interrupted by river estuaries. From Cape Kalkanyar to 30 ° south latitude - a high, deep coast of an abrasion type. To the south (off the coast of Uruguay) there is an abrasion-type coast composed of clays, loess and sand and gravel deposits. In Patagonia, the coasts are represented by high (up to 200 m) cliffs with loose deposits. The shores of Antarctica are 90% composed of ice and belong to the ice and thermal abrasion type.

Bottom relief. At the bottom of the Atlantic Ocean, the following major geomorphological provinces are distinguished: the underwater margin of the continents (shelf and continental slope), the ocean floor (deep-water basins, abyssal plains, zones of abyssal hills, uplifts, mountains, deep-sea trenches), mid-ocean ridges.

The boundary of the continental shelf (shelf) of the Atlantic Ocean passes on average at depths of 100-200 m, its position can vary from 40-70 m (near Cape Hatteras and the Florida Peninsula) to 300-350 m (Weddell Cape). Shelf width from 15-30 km (northeast of Brazil, Iberian Peninsula) to several hundred km (North Sea, Gulf of Mexico, Newfoundland Bank). In high latitudes, the shelf relief is complex and bears traces of glacial influence. Numerous uplifts (banks) are separated by longitudinal and transverse valleys or trenches. Off the coast of Antarctica on the shelf are ice shelves. At low latitudes, the shelf surface is more even, especially in the areas where terrigenous material is carried out 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 averages 1-2° and varies from 1° (regions of Gibraltar, the Shetland Islands, parts of the coast of Africa, 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 area of ​​the Bahamas and the Puerto Rico Trench. Active margins are characterized by high seismicity. The surface of the slope is dissected in places by steps, ledges and terraces of tectonic and accumulative origin and longitudinal canyons. At the foot of the continental slope, gently sloping hills up to 300 m high and shallow underwater valleys are often located.

In the middle part of the bottom of the Atlantic Ocean is the largest mountain system of the Mid-Atlantic Ridge. It extends from the island of Iceland to the island of Bouvet for 18,000 km. The width of the ridge is from several hundred to 1000 km. The crest of the ridge runs close to the midline of the ocean, dividing it into eastern and western parts. On both sides of the ridge there are deep-sea basins separated by bottom uplifts. In the western part of the Atlantic Ocean, basins are distinguished from north to south: Labrador (with depths of 3000-4000 m); Newfoundland (4200-5000 m); the 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) with the abyssal plain of Pernambuco; Argentine (5000-6000 m). In the eastern part of the Atlantic Ocean there are basins: Western European (up to 5000 m), Iberian (5200-5800 m), Canary (over 6000 m), Zeleniy Cape (up to 6000 m), Sierra Leone (about 5000 m), Guinean (over 5000 m ), Angolan (up to 6000 m), Cape (over 5000 m) with the abyssal plains of the same name. To the south is the African-Antarctic Basin with the abyssal Weddell Plain. The bottoms of deep-water basins at the foot of the Mid-Atlantic Ridge are occupied by the zone of abyssal hills. The basins are separated by the Bermuda, Rio Grande, Rockall, Sierra Leone, and other uplifts, and by the Kitovy, Newfoundland, and other ridges.

Seamounts (isolated conical elevations 1000 m or more high) on the bottom of the Atlantic Ocean are concentrated mainly in the zone of the Mid-Atlantic Ridge. In the deep waters, large groups of seamounts occur north of Bermuda, in the Gibraltar sector, off the northeast salient of South America, in the Gulf of Guinea, and west of South Africa.

The Puerto Rico deep-sea trenches, Cayman (7090 m), South Sandwich Trench (8264 m) are located near the island arcs. The Romansh Trench (7856 m) is a large fault. The steepness of the slopes of deep-sea trenches is from 11° to 20°. The bottom of the troughs is flat, leveled by accumulation processes.

Geological structure. The Atlantic Ocean arose as a result of the breakup of the Late Paleozoic supercontinent Pangea during the Jurassic. It is characterized by a sharp predominance of passive margins. The Atlantic Ocean borders the adjacent continents along transform faults south of Newfoundland, along the northern coast of the Gulf of Guinea, along the Falkland Submarine Plateau and the Agulhas Plateau in the southern part of the ocean. Active margins are observed in separate areas (in the region of the Lesser Antilles arc and the arc of the South Sandwich Islands), where subduction with underthrust (subduction) of the Atlantic Ocean crust occurs. The Gibraltar subduction zone, limited in length, has been identified in the Gulf of Cadiz.

In the Mid-Atlantic Ridge, the bottom is being pushed apart (spreading) and oceanic crust is forming at a rate of up to 2 cm per year. High seismic and volcanic activity is characteristic. To the north, paleospreading ridges branch off from the Mid-Atlantic Ridge into the Labrador Sea and the Bay of Biscay. In the axial part of the ridge, a rift valley is pronounced, which is absent in the extreme south and in most of the Reykjanes ridge. Within its limits - volcanic uplifts, frozen lava lakes, basaltic lava flows in the form of pipes (pillow-basalts). In the Central Atlantic, fields of metal-bearing hydrotherms have been found, many of which form hydrothermal structures at the outlet (composed of sulfides, sulfates, and metal oxides); metal-bearing sediments have been established. At the foot of the slopes of the valley there are scree and landslides, consisting of blocks and crushed stone of oceanic crust rocks (basalts, gabbro, peridotites). The age of the crust within the Oligocene ridge is modern. The Mid-Atlantic Ridge separates the zones of the western and eastern abyssal plains, where the oceanic basement is covered by a sedimentary cover, the thickness of which increases towards the continental foothills up to 10-13 km due to the appearance of more ancient horizons in the section and the supply of detrital material from land. In the same direction, the age of the oceanic crust increases, reaching the Early Cretaceous (Middle Jurassic north of Florida). Abyssal plains are practically aseismic. The Mid-Atlantic Ridge is crossed by numerous transform faults extending to the adjacent abyssal plains. The thickening of such faults is observed in the equatorial zone (up to 12 per 1700 km). The largest transform faults (Vima, São Paulo, Romansh, etc.) are accompanied by deep incisions (troughs) on the ocean floor. They expose the entire section of the oceanic crust and partially the upper mantle; protrusions (cold intrusions) of serpentinized peridotites are widely developed, forming ridges elongated along the strike of the faults. Many transform faults are transoceanic or main (demarcation) faults. In the Atlantic Ocean, there are so-called intraplate uplifts, represented by underwater plateaus, aseismic ridges and islands. They have oceanic crust of increased thickness and are mainly of volcanic origin. Many of them were formed as a result of the action of mantle jets (plumes); some originated at the intersection of the spreading ridge by large transform faults. Volcanic uplifts include: Iceland Island, Bouvet Island, Madeira Island, Canary Islands, Cape Verde, Azores, Sierra and Sierra Leone Twin Uplifts, Rio Grande and Whale Range, Bermuda Uplift, Cameroon group of volcanoes, etc. In the Atlantic Ocean there are intra-plate uplifts of non-volcanic nature, among which is the underwater Rockall Plateau, separated from the British Isles by the trough of the same name. The plateau is a microcontinent that separated from Greenland in the Paleocene. Another micro-continent that also broke away from Greenland is the Hebrides in northern Scotland. The underwater marginal plateaus off the coast of Newfoundland (Great Newfoundland, Flemish Cap) and off the coast of Portugal (Iberian) separated from the continents as a result of rifting in the late Jurassic - early Cretaceous.

The Atlantic Ocean is 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 million years ago) from the Central Segment. In the Triassic - Early Jurassic, the spreading of the ocean floor was preceded by continental rifting, traces of which are recorded in the form of semi-grabens (see Graben) filled with clastic deposits on the American and North African margins of the ocean. At the end of the Jurassic - the beginning of the Cretaceous, the Antarctic segment began to open up. In the Early Cretaceous, spreading was experienced by the Southern segment in the South Atlantic and the Newfoundland-Iberian segment in the North Atlantic. The opening of the Labrador-British segment began at the end of the Early Cretaceous. At the end of the Late Cretaceous, the Labrador Basin Sea arose here as a result of spreading on the side axis, which continued until the late Eocene. The North and South Atlantics united in the middle of the Cretaceous - Eocene during the formation of the Equatorial segment.

Bottom sediments . The thickness of modern bottom sediments ranges from several meters in the zone of the crest of the Mid-Atlantic Ridge to 5-10 km in the zones of transverse faults (for example, in the Romansh trench) and at the foot of the continental slope. In deep-water basins, their thickness is from several tens to 1000 m. Over 67% of the ocean floor area (from Iceland in the north to 57-58 ° south latitude) is covered with calcareous deposits formed by the remains of shells of planktonic organisms (mainly foraminifera, coccolithophorids). Their composition varies from coarse sands (at depths up to 200 m) to silts. At depths greater than 4500-4700 m, calcareous oozes are replaced by polygenic and siliceous planktonic sediments. The former occupy about 28.5% of the area of ​​the ocean floor, lining the bottoms of the basins, and are represented by red deep-sea oceanic clay (deep-sea clayey silts). These sediments contain a significant 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 about 6.7% of the ocean floor area, of which diatom silts (formed by diatom skeletons) are the most common. They are common off the coast of Antarctica and on the shelf of Southwest Africa. Radiolarian muds (formed by radiolarian skeletons) are found mainly in the Angolan Basin. Along the coasts of the ocean, on the shelf and partly on the continental slopes, terrigenous sediments of various compositions (gravel-pebble, sandy, clayey, etc.) are developed. The composition and thickness of terrigenous sediments are determined by the bottom topography, the activity of solid material supply from land, and the mechanism of their transfer. Glacial precipitation carried by icebergs is distributed along the coast of Antarctica, Greenland, Newfoundland, and the Labrador Peninsula; composed of weakly sorted clastic material with boulders included, mostly in the south of the Atlantic Ocean. Sediments (from coarse sand to silt) formed from pteropod shells are often found in the equatorial part. Coral sediments (coral breccias, pebbles, sands and silts) are localized in the Gulf of Mexico, the Caribbean Sea and off the northeast coast of Brazil; their maximum depth is 3500 meters. Volcanic sediments are developed near the volcanic islands (Iceland, Azores, Canaries, Cape Verde, etc.) and are represented by fragments of volcanic rocks, slag, pumice, and volcanic ash. Modern chemogenic sediments are found on the Great Bahama Bank, in the Florida-Bahamas, Antilles regions (chemogenic and chemogenic-biogenic carbonates). In the basins of the North American, Brazilian, and Green Cape, ferromanganese nodules are found; their composition in the Atlantic Ocean: 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 off the east coast of the United States and the northwest coast of Africa. Phosphorites are distributed along the eastern coast of the Atlantic Ocean - from the Iberian Peninsula to Cape Agulhas.

Climate. Due to the great length of the Atlantic Ocean, its waters are located in almost all natural climatic zones - from the subarctic in the north to the Antarctic in the south. From the north and south, the ocean is widely open to the influence of arctic and antarctic waters and ice. The lowest air temperature is observed in the polar regions. Over the coast of Greenland, temperatures can drop to -50°C, while temperatures of -32.3°C have been recorded in the southern Weddell Sea. 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 Northern and Southern hemispheres (40-60 °) - cyclones, in lower latitudes - anticyclones, separated by a zone of low pressure at the equator. This baric structure maintains stable easterly winds (trade winds) in tropical and equatorial latitudes, and strong westerly winds in temperate latitudes, which have received the name "roaring forties" from navigators. Strong winds are also characteristic of the Bay of Biscay. In the equatorial region, the interaction of the northern and southern baric systems leads to frequent tropical cyclones (tropical hurricanes), which are most active from July to November. The horizontal dimensions of tropical cyclones are up to several hundred kilometers. 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 is frequent and heavy clouds are observed. Thus, at the equator over 2000 mm of precipitation falls annually, 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 coast of Africa, and in the South Atlantic High, to 100 mm or less per year. In areas where warm and cold currents meet, fogs are frequent, for example, in the area of ​​the Newfoundland bank and in La Plata Bay.

Hydrological regime. Rivers and water balance. In the Atlantic Ocean basin, 19,860 km 3 of water is annually carried out by rivers, which is more than in any other ocean (about 45% of the total flow into the World Ocean). The largest rivers (with an annual flow of over 200 km): Amazon, Mississippi (flows into the Gulf of Mexico), St. Lawrence River, Congo, Niger, Danube (flows into the Black Sea), Parana, Orinoco, Uruguay, Magdalena (flows into the Caribbean Sea ). However, the fresh water balance of the Atlantic Ocean is 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 deficit in the water balance is replenished by the inflow of water, mainly from the Pacific Ocean, through the Drake Strait with the course of the West Winds, 3470 thousand km 3 / year enters, and only 210 thousand km 3 / year goes from the Atlantic Ocean to the Pacific Ocean. From the Arctic Ocean, through numerous straits, 260 thousand km 3 / year enters the Atlantic Ocean and 225 thousand km 3 / year of Atlantic water flows back to the Arctic Ocean. The water balance with the Indian Ocean is negative, 4976 thousand km 3 / year is carried into the Indian Ocean with the course of the West Winds, and only 1692 thousand km 3 / year comes back with the Coastal Antarctic current, deep and bottom waters.

Temperature regime. The average temperature of the ocean waters as a whole is 4.04 °C, and that of surface waters is 15.45 °C. The distribution of water temperature on the surface is asymmetric with respect to the equator. The strong influence of Antarctic waters leads to the fact that the surface waters of the Southern Hemisphere are almost 6 ° C colder than the Northern Hemisphere, the warmest waters of the open part of the ocean (thermal equator) are between 5 and 10 ° north latitude, that is, they are shifted 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 western coasts of the ocean is approximately 5 ° C higher than that of the eastern ones. The warmest water temperature (28-29 ° C) on the surface in the Caribbean Sea and the Gulf of Mexico in August, the lowest - off the coast of Greenland, Baffin Island, the Labrador Peninsula and Antarctica, south of 60 °, where even in summer the water temperature does not rise above 0 °C. The water temperature in the layer of the main thermocline (600-900 m) is about 8-9 °C, deeper, in intermediate waters, it drops to an average of 5.5 °C (1.5-2 °C in Antarctic intermediate waters). In deep waters, the water temperature is on average 2.3 °C, in bottom waters - 1.6 °C. At the very bottom, the water temperature rises slightly due to the geothermal heat flow.

Salinity. The waters of the Atlantic Ocean contain about 1.1·10 16 tons of salts. The average salinity of the waters of the entire ocean is 34.6‰, and that of surface waters is 35.3‰. The highest salinity (over 37.5‰) is observed on the surface in subtropical regions, where the evaporation of water from the surface exceeds its inflow with precipitation, the lowest (6-20‰) in the estuarine sections of large rivers flowing into the ocean. From the subtropics to high latitudes, salinity on the surface decreases to 32-33‰ under the influence of precipitation, ice, river and surface runoff. In temperate and tropical regions, the maximum salinity values ​​are on the surface, an intermediate minimum of salinity is observed at depths of 600-800 m. The waters of the northern part of the Atlantic Ocean are characterized by a deep salinity maximum (more than 34.9‰), which is formed by highly saline Mediterranean waters. The deep waters of the Atlantic Ocean have a salinity of 34.7-35.1‰ and a temperature of 2-4 °C, bottom waters occupying the deepest depressions of the ocean, respectively, 34.7-34.8‰ and 1.6 °C.

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

Ice regime. In the northern part of the Atlantic Ocean, first-year ice forms mainly in the inland seas of temperate latitudes; multi-year ice is carried out of the Arctic Ocean. The boundary of the distribution of the ice cover in the northern part of the Atlantic Ocean varies significantly; in winter, pack ice can reach 50-55 ° north latitude in different years. There is no ice in summer. The boundary of Antarctic multi-year ice in winter runs at a distance of 1600-1800 km from the coast (approximately 55 ° south latitude), in summer (in February - March) ice is found only in the coastal strip of Antarctica and in the Weddell Sea. The main suppliers of icebergs are the ice sheets and ice shelves of Greenland and Antarctica. The total mass of icebergs coming from the Antarctic glaciers is estimated at 1.6·10 12 tons per year, their main source is the Filchner Ice Shelf in the Weddell Sea. Icebergs with a total mass of 0.2-0.3·10 12 tons per year enter the Atlantic Ocean from the glaciers of the Arctic, mainly from the Jakobshavn glacier (near Disko Island off the western coast of Greenland). The average life expectancy of Arctic icebergs is about 4 years, Antarctic icebergs are somewhat longer. The iceberg distribution limit in the northern part of the ocean is 40° north latitude, but in some cases they have been observed up to 31° north latitude. In the southern part, the boundary passes at 40° S latitude in the central part of the ocean and at 35° S latitude on the western and eastern periphery.

currents. The circulation of the waters of the Atlantic Ocean is subdivided into 8 quasi-stationary oceanic circulations, located almost symmetrically with respect to the equator. From low to high latitudes in the Northern and Southern Hemispheres there are tropical anticyclonic, tropical cyclonic, subtropical anticyclonic, subpolar cyclonic oceanic gyres. Their boundaries, as a rule, make up the main ocean currents. The Gulf Stream flows off the Florida peninsula. Absorbing the waters of the warm Antilles Current and the Florida Current, the Gulf Stream heads northeast and at high latitudes is divided into several branches; the most significant of them is the Irminger Current, which carries warm waters to the Davis Strait, the North Atlantic Current, the Norwegian Current, going to the Norwegian Sea and further to the northeast, along the coast of the Scandinavian Peninsula. To meet them, the cold Labrador Current emerges from the Davis Strait, the waters of which can be traced off the coast of America almost to 30 ° north latitude. From the Danish Strait, the cold East Greenland Current flows into the ocean. In the low latitudes of the Atlantic Ocean, warm Northern trade wind currents and Southern trade wind currents are directed from east to west, between them, at about 10 ° north latitude, from west to east, there is an Intertrade countercurrent, which is active mainly in the summer in the Northern Hemisphere. The Brazilian Current separates from the South Trade Wind Currents, which runs from the equator to 40 ° south latitude along the coast of America. The northern branch of the South Trade Winds forms the Guiana Current, which is directed from south to northwest until it joins the waters of the North Trade Winds. Off the coast of Africa, from 20 ° north latitude to the equator, the warm Guinea current passes, in the summer the Inter-trade countercurrent connects with it. In the southern part, the Atlantic Ocean is crossed by the cold West Wind Current (Antarctic Circumpolar Current), which enters the Atlantic Ocean through the Drake Passage, descends to 40 ° south latitude and exits into the Indian Ocean south of Africa. The Falkland Current, which runs along the coast of America almost to the mouth of the Parana River, and the Benguela Current, which runs along the coast of Africa almost to the equator, separate from it. The 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 Northern trade winds.

Deep water circulation. The deep circulation and structure of the waters of the Atlantic Ocean are formed as a result of a change in their density during cooling of waters or in zones of mixing of waters of different origin, where density increases as a result of mixing of waters with different salinities and temperatures. Subsurface waters are formed in 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 the 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. Deep waters are formed in the high latitudes of the northern and southern parts of the ocean. The waters formed in the Antarctic region have the highest density and spread from south to north in the bottom layer, their temperature is from negative (in high southern latitudes) to 2.5 ° C, salinity is 34.64-34.89‰. The waters formed in the high northern latitudes move from north to south in the 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, V.N. Stepanov and, later, V.S. The broker substantiated the scheme of planetary interoceanic transfer of energy and matter, which was called the "global conveyor" or "global thermohaline circulation of the World Ocean". According to this theory, relatively salty North Atlantic waters reach the coast of Antarctica, mix with supercooled shelf water and, passing through the Indian Ocean, end their journey in the North Pacific Ocean.

Tides and excitement. The tides in the Atlantic Ocean are predominantly semidiurnal. Tidal wave height: 0.2-0.6 m in the open part of the ocean, a few centimeters in the Black Sea, 18 meters in the Bay of Fundy (the northern part of the Gulf of Maine in North America) is the highest in the world. The height of wind waves depends on the speed, exposure time and wind acceleration, during strong storms it can reach 17-18 m. Quite rarely (once every 15-20 years) waves of 22-26 m were observed.

Flora and fauna. The great extent of the Atlantic Ocean, a variety of climatic conditions, a significant inflow of fresh water and large upwellings provide a variety of habitat conditions. In total, about 200 thousand species of plants and animals live in the ocean (of which about 15,000 species of fish, about 600 species of cephalopods, about 100 species of whales and pinnipeds). Life is distributed very unevenly in the ocean. There are three main types of zonality in the distribution of life in the ocean: latitudinal or climatic, vertical and circumcontinental zonality. 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 also decreases from tropical to high latitudes.

Planktonic organisms (phytoplankton and zooplankton) are the basis of the food chain in the ocean, most of them live in the upper zone of the ocean, where light penetrates. The highest plankton biomass is in high and temperate latitudes during the spring-summer bloom (1-4 g/m3). During the year, biomass can change by 10-100 times. The main types of phytoplankton are diatoms, zooplankton are copepods and euphausids (up to 90%), as well as chaetognaths, hydromedusae, ctenophores (in the north) and salps (in the south). At low latitudes, the plankton biomass varies from 0.001 g/m 3 in the centers of anticyclonic gyres to 0.3-0.5 g/m 3 in the Gulf of Mexico and Guinea. Phytoplankton is represented mainly by coccolithins and peridineans, the latter can develop in coastal waters in huge quantities, causing the catastrophic phenomenon of the "red tide". Low latitude zooplankton is represented by copepods, chaetognaths, hyperids, hydromedusae, siphonophores, and other species. There are no clearly pronounced dominant zooplankton species in low latitudes.

Benthos is represented by large algae (macrophytes), which mostly grow at the bottom of the shelf zone, down to a depth of 100 m and cover about 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 speeds of bottom currents, etc. In the high latitudes of the Atlantic Ocean, the main part of phytobenthos is kelp and red algae. In the temperate zone of the northern part of the Atlantic Ocean, along the American and European coasts, there are brown algae (fucus and ascophyllum), kelp, desmarestia and red algae (furcellaria, ahnfeltia, etc.). Zostera is common on soft soils. Brown algae predominate in the temperate and cold zones of the South Atlantic Ocean. In the tropical zone in the littoral, due to strong heating and intense insolation, vegetation on the ground is practically absent. A special place is occupied by the ecosystem of the Sargasso Sea, where floating macrophytes (mainly three species of Sargassum algae) form clusters on the surface in the form of ribbons from 100 m to several kilometers long.

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

There is a great similarity between the faunas of 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 zones. The tropical zone of the Atlantic Ocean is characterized by: fish - various sharks, flying fish, sailboats, various types of tuna and luminous anchovies; from animals - sea turtles, sperm whales, river dolphin inia; cephalopods are also numerous - various types of squids, octopuses, etc.

The deep-sea fauna (zoobenthos) of the Atlantic Ocean is represented by sponges, corals, echinoderms, crustaceans, molluscs, and various worms.

Research History

There are three stages in the study of the Atlantic Ocean. The first is characterized by the establishment of the boundaries of the ocean and the discovery of its individual objects. In the 12-5 centuries BC, the Phoenicians, Carthaginians, Greeks and Romans left descriptions of sea travels and the first sea charts. Their voyages reached the Iberian Peninsula, England and the mouth of the Elbe. In the 4th century BC, Pytheas (Pytheas), while sailing in the North Atlantic, determined the coordinates of a number of points and described the tidal phenomena in the Atlantic Ocean. Mentions of the Canary Islands date back to the 1st century AD. In the 9th-10th centuries, the Normans (Eirik Raudi and his son Leif Eirikson) crossed the ocean, visited Iceland, Greenland, Newfoundland and explored the coast of North America up to 40 ° north latitude. During the Age of Discovery (mid-15th - mid-17th century), navigators (mainly the Portuguese and Spaniards) mastered the route to India and China along the coast of Africa. The most outstanding voyages during this period were made by the Portuguese B. Dias (1487), the Genoese H. Columbus (1492-1504), the Englishman J. Cabot (1497) and the Portuguese Vasco da Gama (1498), who for the first time tried to measure the depths of the open parts of the ocean and speed of surface currents.

The first bathymetric map (depth map) of the Atlantic Ocean was compiled in Spain in 1529. In 1520, F. Magellan for the first time passed from the Atlantic Ocean to the Pacific Ocean through the strait, later named after him. In the 16th and 17th centuries, the Atlantic coast of North America was intensively explored (the British J. Davis, 1576-78, G. Hudson, 1610, W. Buffin, 1616, and other navigators whose names can be found on the ocean map). The Falkland Islands were discovered in 1591-92. The southern shores of the Atlantic Ocean (the continent of Antarctica) were discovered and first described by the Russian Antarctic expedition of F. F. Bellingshausen and M. P. Lazarev in 1819-21. This completed the study of the boundaries of the ocean.

The second stage is characterized by the study of the physical properties of ocean waters, temperature, salinity, currents, etc. In 1749, the Englishman G. Ellis carried out the first temperature measurements at various depths, repeated by the Englishman J. Cook (1772), the Swiss O. Saussure (1780), Russian I.F. Kruzenshtern (1803) and others. In the 19th century, the Atlantic Ocean became a testing ground for testing new methods for studying depths, new techniques and new approaches to organizing work. For the first time, bathometers, deep-sea thermometers, thermal depth gauges, deep-sea trawls and dredges are used. Of the most significant, Russian expeditions on the ships "Rurik" and "Enterprise" under the leadership of O.E. Kotzebue (1815-18 and 1823-26); English - on "Erebus" and "Terror" under the leadership of J. Ross (1840-43); American - on the "Seyklab" and "Arktika" under the leadership of M.F. Mori (1856-57). Real complex oceanographic research of the ocean began with an expedition on the English corvette "Challenger", led by C.W. Thomson (1872-76). The following significant expeditions were carried out on the ships Gazelle (1874-76), Vityaz (1886-89), Valdivia (1898-1899), Gauss (1901-03). A great contribution (1885-1922) to the study of the Atlantic Ocean was made by Prince Albert I of Monaco, who organized and led expeditionary research on the yachts Irendel, Princess Alice, Irendel II, Princess Alice II in the northern part of the ocean. In the same years he organized the Oceanographic Museum in Monaco. Since 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, which is still active today, organizing and coordinating ocean research.

After the 2nd World War, the echo sounder began to be widely used to study the ocean floor. This made it possible to obtain a real picture of the topography of the ocean floor. In the 1950-70s, complex geophysical and geological studies of the Atlantic Ocean were carried out and the features of the topography of its bottom and tectonics, and the structure of the sedimentary strata were established. Many large forms of bottom topography (submarine ridges, mountains, trenches, fault zones, vast basins and uplifts) have been identified, and geomorphological and tectonic maps have been compiled.

The third stage of ocean research is mainly aimed at studying its role in the global processes of matter and energy transfer and its influence on climate formation. The complexity and wide range of research work required extensive international cooperation. The Scientific Committee for Oceanographic Research (SCOR), formed in 1957, the Intergovernmental Oceanographic Commission of UNESCO (IOC), which has been operating since 1960, and other international organizations play an important role in coordinating and organizing international research. In 1957-58, a lot of work was carried out within the framework of the first International Geophysical Year (IGY). Subsequently, major international projects were aimed not only at studying individual parts of the Atlantic Ocean (for example, EQUALANT I-III; 1962-1964; Polygon, 1970; SICAR, 1970-75; POLIMODE, 1977; TOGA, 1985-89), but also at its study as part of the World Ocean (GEOSECS, 1973-74; WOCE, 1990-96, etc.). During the implementation of these projects, the features of the circulation of waters of various scales, the distribution and composition of suspended matter, the role of the ocean in the global carbon cycle, and many other issues were studied. In the late 1980s, the Soviet deep-sea submersibles Mir explored the unique ecosystems of the geothermal regions of the ocean's rift zone. If in the early 1980s there were about 20 international ocean research projects, then by the 21st century - over 100. The largest programs are: "International Geosphere-Biosphere Program" (since 1986, 77 countries participate), it includes projects "Interaction land - ocean in the coastal zone" (LOICZ), "Global flows of matter in the ocean" (JGOFS), "Dynamics of global ocean ecosystems" (GLOBES), "World Climate Research Program" (since 1980, 50 countries participate) and many others. The Global Ocean Observing System (GOOS) is being developed.

Economic use

The Atlantic Ocean occupies the most important place in the world economy among other oceans of our planet. Human use of the Atlantic Ocean, as well as other seas and oceans, goes in several main areas: transport and communications, fishing, mining, energy, recreation.

Transport. For 5 centuries, the Atlantic Ocean has played 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. The Atlantic Ocean accounts for about 3/5 of the world's shipping turnover; at the end of the 20th century, up to 3.5 billion tons of cargo per year were transported through its waters (according to IOC). About 1/2 of the volume of traffic is oil, gas and oil products, followed by general cargo, then iron ore, grain, coal, bauxite and alumina. The main direction of transportation is the North Atlantic, which runs between 35-40° north latitude and 55-60° north latitude. The main shipping routes connect the port cities of Europe, the USA (New York, Philadelphia) and Canada (Montreal). The sea routes of the Norwegian, Northern and inland seas of Europe (Baltic, Mediterranean and Black) adjoin this direction. Mainly raw materials (coal, ores, cotton, timber, etc.) and general cargo are transported. Other important directions of transportation are the South Atlantic: Europe - Central (Panama, etc.) and South America (Rio de Janeiro, Buenos Aires); East Atlantic: Europe - South Africa (Cape Town); West Atlantic: North America, South America - southern Africa. Prior to the reconstruction of the Suez Canal (1981), most of the oil tankers from the Indian Basin were forced to go around Africa.

Passenger transportation has been an important part of the Atlantic Ocean since the 19th century, when mass emigration from the Old World to America began. The first steam-sailing ship, the Savannah, crossed the Atlantic Ocean in 28 days in 1818. At the beginning of the 19th century, the Blue Ribbon Prize was established for passenger ships that would cross the ocean the fastest. This prize was awarded, for example, to such famous liners as Lusitania (4 days and 11 hours), Normandie (4 days and 3 hours), Queen Mary (4 days without 3 minutes). The last time the Blue Ribbon was awarded to the US liner United States was in 1952 (3 days and 10 hours). At the beginning of the 21st century, the duration of a passenger liner flight between London and New York is 5-6 days. The maximum passenger traffic across the Atlantic Ocean occurred in 1956-57, when more than 1 million people were transported per year, in 1958 the volume of passenger traffic by air caught up with sea traffic, and then an increasing part of passengers prefer air transport (the record time for a flight of a supersonic liner "Concord" on the route New York - London - 2 hours 54 minutes). The first non-stop flight across the Atlantic Ocean was made on June 14-15, 1919 by English pilots J. Alcock and A. W. Brown (Newfoundland - Ireland), the first non-stop flight across the Atlantic Ocean alone (from continent to continent) on May 20-21, 1927 - American pilot C. Lindbergh (New York - Paris). At the beginning of the 21st century, almost the entire flow of passengers across the Atlantic Ocean is served by aviation.

Connection. In 1858, when there was no radio communication between the continents, the first telegraph cable was laid across the Atlantic Ocean. By the end of the 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, over 10 telephone lines operated on the ocean floor. In 1988, the first transatlantic fiber-optic communication line was laid; in 2001, 8 lines were in operation.

Fishing. The Atlantic Ocean is considered the most productive ocean and its biological resources are most intensively exploited by man. In the Atlantic Ocean, fishing and seafood production account for 40-45% of the total world catch (an area of ​​about 25% of the World Ocean). Most of the catch (up to 70%) is made up of herring fish (herring, sardines, etc.), cod fish (cod, haddock, hake, whiting, saithe, saffron cod, etc.), flounder, halibut, sea bass. Production of shellfish (oysters, mussels, squids, etc.) and crustaceans (lobsters, crabs) is about 8%. According to FAO estimates, the annual catch of fish products in the Atlantic Ocean is 85-90 million tons, but for most of the fishing areas of the Atlantic, the fish catch reached its maximum in the mid-1990s and its increase is undesirable. The traditional and most productive fishing area is the northeastern part of the Atlantic Ocean, including the North and Baltic Seas (mainly herring, cod, flounder, sprats, mackerel). In the northwestern region of the ocean, on the Newfoundland banks, cod, herring, flounder, squid, etc. have been harvested for many centuries. Sardine, horse mackerel, mackerel, tuna, etc. are caught in the central part of the Atlantic Ocean. -Falkland shelf, fishing for both warm-water species (tuna, marlin, swordfish, sardines, etc.) and cold-water species (blue whiting, hake, notothenia, toothfish, etc.). Off the coast of western and southwestern Africa, catching sardines, anchovies and hake. In the Antarctic region of the ocean, planktonic crustaceans (krill), marine mammals, among fish - notothenia, toothfish, silverfish, etc., are of commercial importance. decades, it has declined sharply due to the depletion of biological resources and due to environmental measures, including intergovernmental agreements to limit their extraction.

Mineral resources. The mineral wealth of the ocean floor is being developed more and more actively. Oil and combustible gas fields have been studied more fully, the first mention of their exploitation in the Atlantic Ocean basin dates back to 1917, when oil production began on an industrial scale in the eastern part of the Maracaibo lagoon (Venezuela). Major offshore production centers: Gulf of Venezuela, Maracaibo lagoon (Maracaiba oil and gas basin), Gulf of Mexico (Gulf of Mexico oil and gas basin), Gulf of Paria (Orinok oil and gas basin), Brazilian shelf (Sergipe-Alagoas oil and gas basin), Gulf of Guinea (Gulf of Guinea oil and gas basin) ), the North Sea (North Sea oil and gas region), etc. Placer deposits of heavy minerals are common along many coasts. The largest development of alluvial deposits of ilmenite, monocyte, zircon, rutile are carried out off the coast of Florida. Similar deposits are located in the Gulf of Mexico, off the east coast of the United States, as well as Brazil, Uruguay, Argentina and the Falkland Islands. On the shelf of southwestern Africa, the development of coastal marine diamond placers is underway. Gold-bearing placers were found off the coast of Nova Scotia at depths of 25-45 m. In the Atlantic Ocean, one of the world's largest iron ore deposits, Wabana, has been explored (in Conception Bay off the coast of Newfoundland), iron ore is also being 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. Large sulfur deposits are being developed on the shelf of the Gulf of Mexico. In the coastal zone of the ocean, sand is mined for construction and glass production, gravel. Phosphorite-bearing sediments have been explored on the shelf of the east coast of the United States and the west 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; their total reserves in the Atlantic Ocean are estimated at 45 billion tons.

Recreational resources. Since the 2nd half of the 20th century, the use of ocean recreational resources has been of great importance for the economies of coastal countries. Old resorts are being developed and new ones are being built. Since the 1970s, ocean liners have been laid down, intended only for cruises, they are distinguished by their large size (displacement of 70 thousand tons or more), an increased level of comfort and relative slowness. The main routes of cruise liners are the Atlantic Ocean - the Mediterranean and Caribbean Seas and the Gulf of Mexico. Since the end of the 20th - the beginning of the 21st century, scientific tourism and extreme cruise routes have been developing, mainly in the high latitudes of the Northern and Southern hemispheres. In addition to the Mediterranean and Black Sea basins, the main resort centers are located in the Canaries, Azores, Bermuda, the Caribbean Sea and the Gulf of Mexico.

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

Port cities. Most of the world's major ports are located on the shores of the Atlantic Ocean: in Western Europe - Rotterdam, Marseille, Antwerp, London, Liverpool, Genoa, Le Havre, Hamburg, Augusta, Southampton, Wilhelmshaven, Trieste, Dunkirk, Bremen, Venice, Gothenburg, Amsterdam, Naples, Nantes St. Nazaire, Copenhagen; in North America - New York, Houston, Philadelphia, Baltimore, Norfolk-Newport, Montreal, Boston, New Orleans; in South America - Maracaibo, Rio de Janeiro, Santos, Buenos Aires; in Africa - Dakar, Abijan, Cape Town. Russian port cities do not have direct access to the Atlantic Ocean and are located on the shores of inland seas belonging to its basin: St. Petersburg, Kaliningrad, Baltiysk (Baltic Sea), Novorossiysk, Tuapse (Black Sea).

Lit.: Atlantic Ocean. M., 1977; Safyanov G. A. Coastal zone of the ocean in the XX century. M., 1978; Terms. Concepts, reference tables / Edited by S. G. Gorshkov. M., 1980; Atlantic Ocean. L., 1984; Biological resources of the Atlantic Ocean / Ed. editor D. E. Gershanovich. M., 1986; Broeker W.S. The great ocean conveyor // Oceanograpy. 1991 Vol. 4. No. 2; Pushcharovsky Yu. M. Tectonics of the Atlantic with elements of nonlinear geodynamics. M., 1994; World ocean atlas 2001: In 6 vol. Silver Spring, 2002.

P. N. Makkaveev; A. F. Limonov (geological structure).

In the school course of studying the oceans, the Atlantic must be passed. This water area is quite interesting, which is why we will pay attention to it in our article. So, here is the characteristic of the Atlantic Ocean according to the plan:

1. Hydronym.
2. Basic moments.
3. Temperature regime.
4. Salinity of water.
5. Seas and islands of the Atlantic Ocean.
6. Flora and fauna.
7. Minerals.
8. Problems.

You will also find here a brief comparative description of the Pacific and Atlantic oceans.

hydronym

The Atlantic Ocean, whose characteristics are presented below, got its name thanks to the ancient Greeks, who believed that the hero of myths, Atlas, holds the sky at the edge of the Earth. The modern name was established in the 16th century, during the time of great navigators and discoveries.

Basic moments

The Atlantic Ocean stretches along the globe from north to south from Antarctica to Antarctica, washing 5 continents: Antarctica, North and South America, Eurasia and Africa. Its area is 91.6 million square kilometers. The deepest point of the Atlantic is the Puerto Rican Trench (8742 m), and the average depth is about 3.7 thousand m.

A characteristic feature of the second largest ocean is its elongated shape. The Mid-Atlantic Ridge runs along the Atlantic, which separates South American, Caribbean and North American in the west; in the east - African and Eurasian. The length of the ridge is 16 thousand km, and the width is about 1 km. Lava eruptions and earthquakes often occur here. The discovery of the Mid-Atlantic Ridge is associated with the laying of a telegraph cable that connected America and Northern Europe in the middle of the 19th century.

Temperature regime

The North Trade Wind, Gulf Stream, North Atlantic, Labrador, Canary and others are currents that shape not only the climate, but the entire Atlantic Ocean. The characteristic of the temperature regime shows the following dynamics: the average water temperature is about 16.9 °C. Conventionally, the ocean can be divided along the equator into 2 parts: northern and southern, each of which has its own climatic features, thanks to the Gulf Stream. The width of the water area near the equator is the smallest, so the influence of the continents is most noticeable here.

Despite the fact that the Atlantic Ocean is considered warm, its extreme southern and northern sections can reach temperatures of 0 ° C and below. Therefore, drifting icebergs can often be found here. Today, their movement is tracked by artificial Earth satellites.

Atlantic Ocean: water feature

The Atlantic Ocean is the most salty. The average salt content is 34.5 ppm. Salinity largely depends on precipitation, fresh water inflow from rivers. The most salty is in tropical latitudes, because there is almost no precipitation here, strong evaporation of moisture due to high temperatures, and almost no fresh water.

Seas and islands of the Atlantic Ocean

Most of the islands are located near the mainland, which determines their continental origin: Great Britain, Ireland and others. There are also volcanic ones here: Canaries, Iceland. But Bermuda is of coral origin.

The indentation of the coastline, bays, seas fully describe the Atlantic Ocean. The characteristics of these reservoirs are very interesting. First of all, let's start with the seas. They are divided into 2 types: internal - Azov, Black, Mediterranean, Baltic, and external - Caribbean and Northern, etc. Also here you can observe bays that are not inferior in size to the seas, for example, Mexican or Biscay. In the Atlantic Ocean there is an unusual sea that has no shores - Sargasso. It got its name because of which its bottom is covered. These algae are covered with air bubbles, which is why they are also called

Flora and fauna

The organic world of the Atlantic is characterized by a variety of living organisms. Here grow red, brown, green algae, a large number of species of phytoplankton (more than 200). Thousands of species of animals live in cold zones, and tens of thousands in warm tropical zones. Whales, seals, fur seals, a lot of fish swim in the Atlantic Ocean: cod, herring, flounder, sardine, etc. Penguins and frigatebirds live in the northern latitudes. Large aquatic animals manatees live off the coast of Africa. They eat plants, which is why they are also called
It so happened historically that the Atlantic Ocean has become a source of fish for the food industry (2/5 of the world catch). Whales, walruses, seals and other animals are also hunted here. It satisfies our needs for lobster, oysters, lobsters, crabs.

Minerals

The ocean floor is very rich in various things and Canada mines coal here. The Gulf of Mexico and Guinea have large reserves of oil and natural gas.

Problems

The increase in anthropogenic influence on the Atlantic Ocean has a negative impact on its inhabitants, and it is no longer able to restore its biological resources on its own. A dangerous situation is observed in the Black and Mediterranean Seas, and the Baltic Sea is considered one of the dirtiest in the world.

Comparative characteristics of the Atlantic Ocean and the Pacific (briefly)

In order to make a brief description of the two oceans, you need to use a clear plan:

• The size of the water areas. Atlantic covers an area of ​​more than 91 million square meters. km, Quiet - 178.684 million square meters. km. Based on this, certain conclusions can be drawn. The Pacific Ocean is the largest, the Atlantic - in second place in terms of area.
• Depth. If we compare the depth indicator, then in the Pacific Ocean the average level stops at 3976 m, in the Atlantic - 3736 m. As for the maximum depth, in the first case - 11022 m, in the second - 8742 m.
• Water volume. According to this criterion, the Atlantic Ocean also remains in second place. His figure is 329.66 million cubic meters. km, when in the Pacific - 710.36 million cubic meters. m.
• Location. Atlantic Ocean coordinates - 0° N. sh. 30°W D., washes the following continents and islands: Greenland, Iceland (north), Eurasia, Africa (east), America (west), Antarctica (South). Pacific Ocean coordinates - 009 ° s. sh. 157°W e, located between Antarctica (south), North and South America (east), Australia and Eurasia (west).

Summing up

This article presents a brief description of the Atlantic Ocean, after reading which, you can already have a sufficient idea of ​​​​this area.

The Atlantic Ocean is considered one of the largest and most voluminous in size, namely the second largest after the Pacific Ocean. This ocean, the most studied and developed, when compared with other areas. Its location is as follows: from the east it is framed by the shores of North and South America, and in the west its borders end with Europe and Africa. In the South, it passes into the Southern Ocean. And on the north side it borders on Greenland. The ocean is distinguished by the fact that there are very few islands in it, and the topography of its bottom is all dotted and has a complex structure. The coastline is broken.

Characteristics of the Atlantic Ocean

If we talk about the area of ​​\u200b\u200bthe ocean, then it occupies 91.66 million square meters. km. We can say that part of its territory is not the ocean itself, but the existing seas, bays. The volume of the ocean is 329.66 million square meters. km, and its average depth is 3736 m. Where the Puerto Rico trench is located, it is considered the greatest depth of the ocean, which is 8742 m. There are two currents - North and South.

Atlantic Ocean from the north side

The border of the ocean from the north is marked in some places by ridges located under water. In this hemisphere, the Atlantic is framed by a rugged coastline. Its small northern part is connected to the Arctic Ocean by several narrow straits. Davis Strait is located in the northeast and connects the ocean with the Baffin Sea, which is also considered to belong to the Arctic Ocean. Closer to the center is the Danish Strait, which is less wide than Davis. Between Norway and Iceland towards the northeast lies the Norwegian Sea.

The Gulf of Mexico is located in the southwest of the North Ocean, which is connected by the Strait of Florida. Also the Caribbean. Many bays can be noted here, such as Barnegat, Delaware, Hudson Bay and others. It is in the northern side of the ocean that you can see the largest and largest islands, which are famous for their fame. These are Puerto Rico, the world famous Cuba and Haiti, as well as the British Isles and Newfoundland. Closer to the east you can find small groups of islands. These are the Canary Islands, Azores and Cape Verde. Closer to the west - the Bahamas, Lesser Antilles.

South Atlantic Ocean

Some of the geographers believe that the southern part is the entire space to the Antarctic. Someone defines the border at Cape Horn and the Cape of Good Hope of the two continents. The coast in the south of the Atlantic Ocean is not as indented as in the north, and there are no seas here. There is one large gulf near Africa - Guinea. The farthest point in the south is Tierra del Fuego, which is framed by small islands in large numbers. Also, you cannot find large islands here, but there are separate islands, like about. Ascension, St. Helena, Tristan da Cunha. In the extreme south you can find the South Islands, Bouvet, Falkland and others.

As for the current in the south of the ocean, here all systems flow counterclockwise. Near the east of Brazil, the South Equatorial Current forks. One branch goes north, flows near the northern coast of South America, filling the Caribbean. And the second is considered southern, very warm, moves near Brazil and soon connects with the Antarctic current, then heads to the east. Partially separates and turns into the Benguela Current, which is distinguished by its cold waters.

Landmarks of the Atlantic Ocean

There is a special underwater cave in the Belize Barrier Reef. They called it the Blue Hole. It is very deep, and inside it there is a whole series of caves, which are interconnected by tunnels. Deep into the cave reaches 120 m and is considered unique in its kind.

There is no person who does not know about the Bermuda Triangle. But it is located in the Atlantic Ocean and excites the imagination of many superstitious travelers. Bermudas beckon with their mystery, but at the same time they frighten with the unknown.

It is in the Atlantic that you can see an unusual sea that has no shores. And all because it is located in the middle of the body of water, and its boundaries cannot be framed by land, only currents show the boundaries of this sea. This is the only sea in the world that has such unique data and is called the Sargasso Sea.

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It occupies an area of ​​92 million km. It collects fresh water from the most significant part of the land and stands out among other oceans in that it connects both polar regions of the Earth in the form of a wide strait. The Mid-Atlantic Ridge runs through the center of the Atlantic. This is the belt of instability. Individual peaks of this ridge rise above the water in the form. Among them, the largest -.

The southern tropical part of the ocean is under the influence of the southeast trade wind. The sky above this part is slightly clouded with cumulus clouds that look like cotton wool. This is the only place in the Atlantic where there is no. The color of the water in this part of the ocean ranges from dark blue to bright green (near). The waters turn green when approaching, as well as near the southern shores. The tropical part of the South Atlantic is very rich in life: the density of plankton there is 16 thousand individuals per liter; there is an abundance of flying fish, sharks and other predatory fish. There are no builder corals in the southern part of the Atlantic: they have been pushed out of here. Many researchers notice that cold currents in this part of the ocean are richer in life than warm ones.

: 34-37.3‰.

Additional Information: the Atlantic Ocean got its name from the Atlas Mountains located in northwest Africa, according to another version - from the mythical continent Atlantis, according to thirds - on behalf of the titan Atlas (Atlanta); The Atlantic Ocean is conditionally divided into the Northern and Southern regions, the boundary between which runs along the equator line.

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

Physical-geographical sketch

General information

In the north, the border of A. o. with the Arctic basin approx. runs along the east. Hudson Strait entrance, then through Davis Strait. and along the coast. Greenland to Cape Brewster, through the Danish Strait. to Cape Rydinupyur on about. Iceland, along its coast to Cape Gerpir (Terpire), then to the Faroe Islands, then to the Shetland Islands and along 61 ° N. sh. to the coast of the Scandinavian Peninsula. In the east of A. about. bounded by the shores of Europe and Africa, in the west - by the shores of the North. America and South. America. The border of A. o. with Indian ca. carried out along the line passing from Cape Igolny along the meridian 20 ° E. to the coast of Antarctica. The border with the Pacific carried out from Cape Horn along the meridian 68 ° 04′ W. or the shortest distance from Yuzh. America to the Antarctic Peninsula through the strait. Drake, from Fr. Oste to Cape Sternek. South part A. o. sometimes called the Atlantic sector of the Southern Ocean, drawing the border along the subantarctic zone. convergence (approximately 40° S). In some works division A. about is offered. to Sev. and Yuzh. The Atlantic Oceans, but it is more common to consider it as a single ocean. A. o. - 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, limited by currents - Sargasso Sea; Hall. fandi with the highest tidal wave; to the basin of A. o. applies Black Sea with a unique hydrogen sulfide layer.

A. o. 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). Area A. o. with seas, bays and straits 91.66 million km 2, without them - 76.97 million km 2. The volume of water is 329.66 million km 3, without seas, bays and straits - 300.19 million km 3. Wed depth 3597 m, maximum - 8742 m (chute Puerto Rico). The most easily accessible for development shelf zone of the ocean (with depths up to 200 m) occupies approx. 5% of its area (or 8.6%, if we take into account the seas, bays and straits), its area is larger than in the Indian and Pacific Oceans, and significantly 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); interisland - Irish and int. sea ​​west. the coast of Scotland; marginal - Labrador, Northern, Sargasso, Caribbean, Scotia (Scotia), Weddell, Lazarev, zap. part of Riiser-Larsen (see separate articles on the seas). The largest bays of the ocean: Biscay, Bristol, Guinean, Mexican, Maine, St. Lawrence. The most important straits of the ocean: Great Belt, Bosphorus, Gibraltar, Dardanelles, Danish, Davis, Drake, Øresund (Sund), Cabota, Kattegat, Kerch, English Channel (including Pas de Calais), Lesser Belt, Messinian, Skagerrak , Florida, Yucatan.

Islands

Unlike other oceans, in A. o. there are few seamounts, guyots and coral reefs, and there are no coastal reefs. The total area of ​​\u200b\u200bthe islands of A. o. 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 (Land of Fire, Oste, Navarino) , Marajo, Sicily, Sardinia, Lesser Antilles, Falkland (Malvinas), Bahamas, etc. Small islands are found in the open ocean: Azores, Sao Paulo, Ascension, Tristan da Cunha, Bouvet (on the Mid-Atlantic Ridge), etc. .

coast

Coastline in the north. parts of A. o. heavily indented (see also Coast ), almost all major inland seas and bays are located here, in the south. parts of A. o. the banks are slightly indented. The coast of Greenland, Iceland and the coast of Norway preim. tectonic-glacial division of fjord and fiard types. To the south, in Belgium, they give way to sandy shallow shores. Coast of Flanders arr. arts. origin (coastal dams, polders, canals, etc.). The coast of UK and about. Ireland abrasion-bay, high limestone cliffs alternate with sandy beaches and muddy lands. The Cotentin Peninsula has rocky shores, sandy and gravel beaches. Sev. the coast of the Iberian Peninsula is composed of rocks, to the south, off the coast of Portugal, sandy beaches predominate, often fencing off lagoons. Sandy beaches also border the shores of the West. Sahara and Mauritania. To the south of Cape Zeleny there are leveled abrasion-bay shores with mangrove thickets. Zap. the Ivory Coast section has an accumulative coast with rocky headlands. To the southeast, to the vast delta of the river. Niger, - accumulative coast with means. 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. Coasts of the Arctic. Canadas are abrasive, with high cliffs, glacial deposits and limestones. In east. Canada and sowing. parts of the hall. St. Lawrence are intensively eroded limestone and sandstone cliffs. To the west and south of the hall. St. Lawrence - wide beaches. On the shores of the Canadian provinces of Nova Scotia, Quebec, Newfoundland - outcrops of solid crystalline. breeds. From about 40 ° N. sh. to Cape Canaveral in the USA (Florida) - alternation of leveled accumulative and abrasion types of coasts, composed of loose rocks. Coast of the Gulf of Mexico. low-lying, bordered by mangroves in Florida, sand barriers in Texas, and deltaic shores in Louisiana. On the Yucatan Peninsula - cemented beach sediments, to the west of the peninsula - an alluvial-marine plain with coastal ridges. On the coast of the Caribbean Sea, abrasion and accumulative areas alternate with mangrove swamps, alongshore barriers, and sandy beaches. South of 10° N. sh. accumulative banks are common, composed of material carried out from the mouth of the river. Amazon and other rivers. In the northeast of Brazil - a sandy coast with mangroves, interrupted by river estuaries. From Cape Kalkanyar to 30°S sh. - high deep coast of abrasion type. To the south (off the coast of Uruguay) there is an abrasion-type coast composed of clays, loess and sand and gravel deposits. In Patagonia, the coasts are represented by high (up to 200 m) cliffs with loose deposits. 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 margin of the continents (shelf and continental slope), the ocean floor (deep basins, abyssal plains, zones of abyssal hills, uplifts, mountains, deep-sea trenches), mid-oceanic. ridges.

The boundary of the continental shelf (shelf) A. o. takes place on Wed. at depths of 100–200 m, its position can vary from 40–70 m (near Cape Hatteras and the Florida Peninsula) to 300–350 m (Cape Weddell). The shelf width varies from 15–30 km (Northeast Brazil, Iberian Peninsula) to several hundred km (Northern Sea, Gulf of Mexico, Newfoundland Bank). In high latitudes, the shelf relief is complex and bears traces of glacial influence. Numerous uplifts (banks) are separated by longitudinal and transverse valleys or trenches. Off the coast of Antarctica on the shelf are ice shelves. At low latitudes, the shelf surface is more even, especially in the areas where terrigenous material is carried out 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 cf. 1–2° and varies from 1° (areas of Gibraltar, the Shetland Islands, parts of the coast of Africa, 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 area of ​​the Bahamas and the Puerto Rico Trench. Active margins are characterized by high seismicity. The surface of the slope is dissected in places by steps, ledges 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 A. o. is the largest mountain system of the Mid-Atlantic Ridge. It extends from about. Iceland to about. Bouvet at 18,000 km. The width of the ridge is from several hundred to 1000 km. The crest of 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-sea basins separated by bottom uplifts. In zap. parts of A. o. Basins are distinguished from north to south: Labradorskaya (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 Demerara and Ceara plains; brazilian basin(5000–5500 m) with the abyssal plain of Pernambuco; Argentinean (5000–6000 m). In east. parts of A. o. basins are located: Western European (up to 5000 m), Iberian (5200–5800 m), Canary (over 6000 m), Zeleniy Cape (up to 6000 m), Sierra Leone (about 5000 m), Guinea (over 6000 m). 5000 m), Angolan (up to 6000 m), Cape (over 5000 m) with the abyssal plains of the same name. To the south is the African-Antarctic Basin with the abyssal Weddell Plain. The bottoms of deep-water basins at the foot of the Mid-Atlantic Ridge are occupied by the zone of abyssal hills. The basins are separated by the Bermuda, Rio Grande, Rockall, Sierra Leone, and other uplifts, and by the Kitovy, Newfoundland, and other ridges.

Seamounts (isolated conical elevations 1,000 m or more high) at the bottom of the sea. concentrated preim. in the Mid-Atlantic Ridge. In the deep-water part, large groups of seamounts are found north of Bermuda, in the Gibraltar sector, near the northeast. ledge South. America, in the Guinea Hall. and west of South. Africa.

Deep sea trenches of Puerto Rico, Caiman(7090 m), South Sandwich Trench(8264 m) are located near the island arcs. gutter Romansh(7856 m) is a major fault. The steepness of the slopes of deep-sea trenches is from 11° to 20°. The bottom of the troughs is flat, leveled by accumulation processes.

Geological structure

A. o. arose as a result of the collapse of the Late Paleozoic supercontinent Pangea during the Jurassic. It is characterized by a sharp predominance of passive margins. A. o. borders on adjacent continents transform faults south of about. Newfoundland, along the north. coast of the Gulf of Guinea., along the Falkland underwater plateau and the Agulhas plateau in the south. parts of the ocean. Active margins are observed at areas (in the region of the Lesser Antilles arc and the arc of the South Sandwich Islands), where the subsidence occurs ( subduction) lithosphere A. o. The Gibraltar subduction zone, limited in length, has been identified in the Gulf of Cadiz.

In the Mid-Atlantic Ridge, the bottom is moving apart ( spreading) and the formation of oceanic. bark at a rate of up to 2 cm per year. Characterized by high seismic and volcanic. activity. In the north, paleospreading ridges branch off from the Mid-Atlantic Ridge into Cape Labrador and into the Bay of Biscay. In the axial part of the ridge, a rift valley is pronounced, which is absent in the extreme south and on the b. including the Reykjanes Ridge. Within its limits - volcanic. uplifts, solidified lava lakes, basaltic lava flows in the form of pipes (pillow-basalts). To the Center. The Atlantic found fields of metal-bearing hydrotherm, many of which form hydrothermal structures at the outlet (composed of sulfides, sulfates and metal oxides); installed metaliferous sediments. At the foot of the slopes of the valley there are screes and landslides, consisting of blocks and crushed stone of oceanic rocks. bark (basalts, gabbro, peridotites). The age of the crust within the Oligocene ridge is modern. The Mid-Atlantic Ridge separates the zones west. and east. abyssal plains, where oceanich. The basement is covered by a sedimentary cover, the thickness of which increases in the direction of the continental foothills up to 10–13 km due to the appearance of older horizons in the section and the influx of clastic material from land. In the same direction, the age of the oceans is increasing. crust, reaching the Early Cretaceous (north of Middle Jurassic Florida). Abyssal plains are practically aseismic. The Mid-Atlantic Ridge is crossed by numerous transform faults leading to adjacent abyssal plains. The thickening of such faults is observed in the equatorial zone (up to 12 per 1700 km). The largest transform faults (Vima, São Paulo, Romansh, etc.) are accompanied by deep incisions (troughs) on the ocean floor. The entire section of the oceanic is opened in them. crust and partially upper mantle; protrusions (cold intrusions) of serpentinized peridotites are widely developed, forming ridges elongated along the strike of the faults. Mn. transform faults are transoceanic, or main (demarcation). In A. o. there are so-called. intraplate uplifts represented by underwater plateaus, aseismic ridges and islands. They have an oceanic a bark of the increased power also have hl. arr. volcanic origin. Many of them were formed as a result of the action mantle plumes; some originated at the intersection of the spreading ridge by large transform faults. To the volcanic uplifts include: about. Iceland, about Bouvet, oh Madeira, the Canary Islands, the Cape Verde, the Azores, the paired uplifts of Sierra and Sierra Leone, the Rio Grande and the Whale Range, the Bermuda Uplift, the Cameroon group of volcanoes, and others. there are intraplate uplifts of non-volcanic. nature, which includes the underwater plateau of Rockall, separated from the British Isles by the same name. trog. The plateau represents microcontinent, detached from Greenland in the Paleocene. Another micro-continent that also broke away from Greenland is the Hebrides in northern Scotland. The underwater marginal plateaus off the coast of Newfoundland (Great Newfoundland, Flemish Cap) and off the coast of Portugal (Iberian) separated from the continents as a result of rifting at the end of the Jurassic - the beginning of the Cretaceous.

A. o. is 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 million years ago) from the Central Segment. In the Triassic-Early Jurassic, oceanic spreading. the bottom was preceded by the continental rifting, traces of which are recorded in the form of semigrabens filled with clastic deposits on the Amer. and north - afri. the outskirts of the ocean. At the end of the Jurassic - the beginning of the Cretaceous, the Antarctic segment began to open up. In the early Cretaceous, spreading was experienced by Yuzh. segment in South. Atlantic and Newfoundland-Iberian segment in the North. Atlantic. The opening of the Labrador-British segment began at the end of the Early Cretaceous. At the end of the Late Cretaceous, the basin of the Labrador Sea arose here as a result of spreading on the side axis, which continued until the late Eocene. Sev. and Yuzh. The Atlantic united in the middle of the Cretaceous - Eocene during the formation of the Equatorial segment.

Bottom sediments

The thickness of the modern bottom sediments varies from a few m in the zone of the crest of the Mid-Atlantic Ridge to 5–10 km in the zones of transverse faults (for example, in the Romansh trench) and at the foot of the continental slope. In deep-water basins, their thickness varies 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 (main sample foraminifera, coccolithophorid). Their composition varies from coarse sands (at depths up to 200 m) to silts. At depths greater than 4500–4700 m, calcareous muds are replaced by polygenic and siliceous planktonic sediments. The first take approx. 28.5% of the ocean floor area, lining the bottom of the basins, and represented red deep ocean clay(deep-sea clay silts). These sediments contain 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 diatom silts (formed by the skeletons of diatoms) are the most common. They are common off the coast of Antarctica and on the shelf of the Southwest. Africa. Radiolarian oozes (formed by skeletons of radiolarians) meet hl. arr. in the Angolan Basin. Along the coasts of the ocean, on the shelf and partly on the continental slopes, terrigenous sediments of various compositions (gravel-pebble, sandy, clayey, etc.) are developed. The composition and thickness of terrigenous sediments are determined by the bottom topography, the activity of solid material supply from land, and the mechanism of their transfer. Glacial precipitation carried by icebergs is distributed along the coast of Antarctica, about. Greenland, about. Newfoundland, Labrador Peninsula; composed of weakly sorted detrital material with the inclusion of boulders, mostly in the south of the A. o. Sediments (from coarse sand to silt) formed from pteropod shells are often found in the equatorial part. Coral sediments (coral breccias, pebbles, sands and silts) are localized in the Gulf of Mexico, the Caribbean Sea and near the northeast. the coasts of Brazil; their ultimate depth is 3500 m. Volcanic sediments are developed near the volcanic. islands (Iceland, Azores, Canaries, Cape Verde, etc.) and are represented by fragments of volcanic. rocks, slag, pumice, volcanic. ashes. Modern chemogenic sediments are found on the Great Bahama Bank, in the Florida-Bahamas, Antilles regions (chemogenic and chemogenic-biogenic carbonates). In the basins of the North American, Brazilian, Green Cape 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 concretions appear at depths of 200–400 m near the east. US coast and north-west. coast of Africa. Phosphorites are distributed along the east. coast of A. o. - from the Iberian Peninsula to Cape Agulhas.

Climate

Due to the large length of A. o. 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 widely open to the influence 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 Cape Weddell recorded a temperature of –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 temperate latitudes North. and Yuzh. hemispheres (40–60°) - cyclones, at lower latitudes - anticyclones, separated by a zone of low pressure near the equator. This baric structure supports tropical. and equatorial latitudes steady winds east. directions (trade winds), in temperate latitudes - strong winds west. directions, which received the names of the sailors. "roaring forties". Strong winds are also characteristic of the Bay of Biscay. In the equatorial region, the interaction of the sowing. and south. baric systems leads to frequent tropical. cyclones (tropical hurricanes), the greatest activity of which is observed from July to November. Tropical horizontal dimensions. 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 is frequent and heavy clouds are observed. So, at the equator, 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 coasts of Africa and in the South Atlantic High, 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 balance from. In the basin of A. o. 19,860 km 3 of water are annually carried out by rivers, this is more than in any other ocean (about 45% of the total flow into the World Ocean). The largest rivers (with an annual flow of over 200 km 3): Amazon, Mississippi(flows into the Gulf of Mexico.), Saint Lawrence river, Congo, Niger, Danube(flows into the Black Sea) Paraná, Orinoco, Uruguay, Magdalena(flows into the Caribbean). However, the fresh water balance of 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 ice melting and icebergs in the Arctic and Antarctic (about 3 thousand km 3 / year). The deficit of the water balance is compensated by the inflow of waters, Ch. arr. from the Pacific Ocean, through the Drake Strait with the course of the West Winds, 3,470 thousand km 3 / year enter in Pacific ok. only 210 thousand km 3 / year go. From the Arctic ca. through numerous straits in A. about. 260 thousand km 3 / year and 225 thousand km 3 / year are supplied by the Atlantic. water flows back into the Arctic Ocean. Water balance with Indian c. negative, in the Indian apprx. with the course of the West Winds, 4976 thousand km 3 / year are taken out, and come back with the Coastal Antarctic. current, deep and bottom waters, only 1692 thousand km 3 / year.

Temperature regime m. Wed. the temperature of the ocean waters as a whole is 4.04 ° C, and that of surface waters is 15.45 ° C. The distribution of water temperature on the surface is asymmetric with respect to the equator. The 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 ° N. sh., i.e., shifted north of the geographic. equator. Features of large-scale water circulation lead to the fact that the water temperature on the surface near the west. 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 and the Gulf of Mexico. in August, the lowest - off the coast of about. Greenland, about. Baffin Island, 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 Ch. thermocline (600–900 m) is approx. 8–9 °C, deeper, in intermediate waters, descends at cf. up to 5.5 °C (1.5–2 °C in Antarctic intermediate waters). In deep waters, the water temperature in cf. 2.3 °C, in the bottom 1.6 °C. At the very bottom, the temperature of the water increases slightly due to geothermal. heat flow.

Salinity 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‰, and that of surface waters is 35.3‰. The highest salinity (over 37.5‰) is observed on the surface in the subtropical. areas where the evaporation of water from the surface exceeds its inflow with atmospheric precipitation, the smallest (6–20‰) in the estuarine sections of large rivers flowing into the ocean. From the subtropics to high latitudes, salinity on the surface decreases to 32–33‰ under the influence of precipitation, ice, river and surface runoff. In temperate and tropical areas max. salinity values ​​are on the surface, an intermediate salinity minimum is observed at depths of 600–800 m. parts of A. o. are characterized by a deep salinity maximum (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, near-bottom, occupying the deepest depressions of the ocean, respectively 34.7–34.8‰ and 1.6 °C.

Density The density of water depends on temperature and salinity; temperature is of greater importance in the formation of the water density field. Waters with the lowest density are located in the equatorial and tropical regions. zones with a high water temperature and a strong influence of the flow of such rivers as the Amazon, Niger, Congo, etc. (1021.0–1022.5 kg / m 3). In the south part of the ocean, the density of surface waters increases to 1025.0–1027.7 kg/m 3 , in the northern part – up to 1027.0–1027.8 kg/m 3 . Density of deep waters A. o. 1027.8–1027.9 kg / m 3.

Ice regime m. In the north. parts of A. o. first-year ice is formed Ch. arr. in the inner seas of temperate latitudes, multi-year ice is carried out from the Arctic approx. The boundary of the distribution of the ice cover in the sowing. parts of A. o. varies considerably, in winter, pack ice can reach decomp. years 50–55°N sh. There is no ice in summer. Antarctic border. In winter, multi-year ice passes at a distance of 1600-1800 km from the coast (approximately 55 ° S), in summer (February - March) ice is found only in the coastal strip of Antarctica and in Cape Weddell. Main icebergs are supplied by the ice sheets and ice shelves of Greenland and Antarctica. The total mass of icebergs coming from the Antarctic. glaciers, estimated at 1.6 × 10 12 tons per year, main. their source is the Filchner Ice Shelf in Cape Weddell. From the glaciers of the Arctic to the A. O. icebergs with a total mass of 0.2–0.3 × 10 12 tons arrive per year, in the main. from the Jacobshavn glacier (near Disko Island off the western coast of Greenland). Wed arctic lifespan. icebergs approx. 4 years, Antarctic a little more. The border of distribution of icebergs in sowing. parts of the ocean 40 ° N. sh., but in otd. cases they were observed up to 31 ° C. sh. In the south part of the boundary passes at 40 ° S. sh., in the center. parts of the ocean and at 35 ° S. sh. on the app. and east. periphery.

I flow. Water circulation A. o. subdivided into 8 quasi-stationary oceanic. gyres located almost symmetrically about the equator. From low to high latitudes in the North. and Yuzh. hemispheres are tropical. anticyclonic, tropical cyclonic, subtropical anticyclonic, subpolar cyclonic. oceanic cycles. Their boundaries, as a rule, are Ch. oceanic currents. A warm current begins off the Florida Peninsula Gulfstream. Taking in the 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 are Irminger Current, which carries warm water into Davis Strait, the North Atlantic Current, norwegian current, going to the Norwegian Sea and further to the northeast, along the coast of the Scandinavian Peninsula. To meet them from Devisova Prospekt. comes out cold Labrador Current, whose waters can be traced off the coast of America to almost 30 ° N. sh. From Danish Strait. the cold East Greenland current flows into the ocean. In low latitudes A. about. warm temperatures move from east to west northern trade winds And South trade winds, between them, approximately 10 ° N. sh., from west to east there is an Intertrade countercurrent, which is active Ch. arr. summer in Sev. hemisphere. separates from the southern trade winds brazilian current, which runs from the equator to 40 ° S. sh. along the coast of America. Sev. branch of the South trade wind currents forms Guiana current, which is directed from south to northwest to the connection with the waters of the Northern trade winds. Off the coast of Africa from 20 ° N. sh. the warm Guinea current passes to the equator, in the summer the Intertrade countercurrent connects with it. In the south parts of A. o. crosses the cold West winds flow(Antarctic circumpolar current), which is included in the A. about. through the strait Drake, descends to 40 ° S. sh. and goes to the Indian ca. south of Africa. The Falkland current separates from it, reaching along the coast of America almost to the mouth of the river. Parana, the Benguela Current, running 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 Northern trade winds.

Deep circulation during e. Deep circulation and structure of waters A. o. are formed as a result of a change in their density during cooling of waters or in zones of mixing of waters decomp. origin, where the density increases as a result of the mixing of waters with decomp. salinity and temp. 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 10–22 °C and a salinity of 34.8–36.0‰. Intermediate waters are formed in the 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. and south. parts of the ocean. 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‰. 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 V. N. Stepanov and, later, V. S. 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 Ocean, end their journey in the sowing. parts of the Pacific Ocean.

Tides and waves e. Tides in A. o. preim. semi-diurnal. Tidal wave height: 0.2–0.6 m in the open part of the ocean, a few cm in the Black Sea, 18 m in the bay. Fundy (the northern part of the Gulf of Maine in North America) is the highest in the world. The height of wind waves depends on the speed, exposure time and wind acceleration; during strong storms it can reach 17–18 m. 22–26 m.

Flora and fauna

The large length of the A. O., the variety of climatic. conditions, that is. inflow of fresh water and large upwellings provide a variety of living conditions. In total, approx. 200,000 species of plants and animals (including about 15,000 fish species, about 600 species of cephalopods, about 100 species of whales and pinnipeds). Life is distributed very unevenly in the ocean. There are three main the type of zonality 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 also decreases from tropical. latitudes to high.

Planktonic organisms (phytoplankton and zooplankton) are the basis of the food chain in the ocean, osn. their mass lives in the upper zone of the ocean, where light penetrates. The highest plankton biomass is in high and temperate latitudes during spring and summer blooms (1–4 g/m3). During the year, biomass can change by 10–100 times. Main phytoplankton species - diatoms, zooplankton - copepods and euphausids (up to 90%), as well as chaetognaths, hydromedusae, ctenophores (in the north) and salps (in the south). At low latitudes, the plankton biomass varies from 0.001 g/m 3 in the centers of anticyclonics. gyres up to 0.3–0.5 g/m 3 in the Gulf of Mexico and Guinea. Phytoplankton is represented by Ch. arr. coccolithins and peridineas, the latter can develop in coastal waters in large quantities, causing catastrophic. red tide phenomenon. Low-latitude zooplankton is represented by copepods, chaetognaths, hyperids, hydromedusae, siphonophores, and other species. There are no clearly pronounced dominant zooplankton species in low latitudes.

Benthos is represented by large algae (macrophytes), which b. hours 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 fastening to the bottom, the absence or moderate speeds of near-bottom currents, and so on. main part of the phytobenthos is made up of kelp and red algae. In the temperate zone, parts of the sea, along the American and European coasts, are brown algae (fucus and ascophyllum), kelp, desmarestia, and red algae (furcellaria, ahnfeltia, and others). Zostera is common on soft soils. In the temperate and cold zones of the south. parts of A. o. brown algae predominate. In 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 Sargasso Cape ecosystem, where floating macrophytes (mainly three species of algae of the genus Sargassum) form clusters on the surface in the form of ribbons ranging in length from 100 m to several. kilometers.

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

There is a great similarity between the faunas of 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 zones. For the tropical A.'s zones about. characteristic: from fish - dec. sharks, flying fish, sailboats, decomp. species of tuna and glowing anchovies; from animals - sea turtles, sperm whales, river dolphin inia; numerous and cephalopods - diff. species of squid, octopus, etc.

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

Research History

Allocate three stages of research And. The first is characterized by the establishment of the boundaries of the ocean and the discovery of its individual objects. AT 12- 5th century BC e. Phoenicians, Carthaginians, Greeks and Romans left descriptions of maritime wanderings and the first sea charts. Their voyages reached the Iberian Peninsula, England and the mouth of the Elbe. In the 4th c. BC e.Piteas(Pytheas) while sailing to the North. Atlantic, he determined the coordinates of a number of points and described the tidal phenomena in the A. O. By the 1st century n. e. include references to the Canary Islands. In the 9th-10th centuries. Normans (RowdyEirik and his son Leif Eirikson) crossed the ocean, visited Iceland, Greenland, Newfoundland and explored the shores of the North. America under 40° c. sh. In the eraGreat geographical discoveries(mid. 15th - mid. 17th centuries) navigators (mainly the Portuguese and Spaniards) mastered 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), Genoese H.Columbus(1492–1503), 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. The first bathymetric map (depth map) was compiled in Spain in 1523. In 1520 F.Magellanfirst passed from A. o. in Pacific ok. strait, later named after him. In the 16th and 17th centuries Atlantic is intensively studied. coast of the North. America (English J.Davis, 1576–78, G. Hudson, 1610, W. Baffin, 1616, and other sailors whose names can be found on the map of the ocean). The Falkland Islands were discovered in 1591–92. South shores of A. o. - the mainland Antarctica - were discovered and first described by 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 made the first temperature measurements at various depths, repeated by the Englishman J. cook(1772), Swiss O. Saussure(1780), Russian. I.F. Kruzenshtern(1803) and others. In the 19th century. A. o. becomes a testing ground for testing new methods of depth research, new equipment and new approaches to the organization of work. For the first time, bathometers, deep-sea thermometers, thermal depth gauges, deep-sea trawls and dredges are used. Of the most significant expeditions can be noted Rus. sailing on the ships "Rurik" (1815-18) and "Enterprise" (1823–26) under the direction 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.Maury(1856). True complex oceanographic ocean exploration began with an expedition in English. corvette« Challenger "led by W. Thomson (1872-76). The following significant expeditions were carried out on the ships Gazelle (1874-76), Vityaz (1886-89), Valdivia (1898-99), Gauss (1901-03). From 1885 to 1922, a great contribution to the study of A. o. introduces Prince Albert I of Monaco, who organized and led 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. Since 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 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, which is still active today and organizes and coordinates ocean research.

After the 2nd World War, the echo sounder began to be widely used to study the ocean floor. This made it possible to obtain a real picture of the topography of the ocean floor. In the 1950s–70s. carried out complex geophysical. and geological. A.'s research about. and established the features of the relief of its bottom and tectonics, the structure of the sedimentary strata. Many large forms of bottom topography (submarine ridges, mountains, trenches, fault zones, vast basins and uplifts) have been identified, and geomorphological data have been compiled. and tectonic. cards. Unique results were obtained under the IODP International Deep Sea Ocean Drilling Program (1961–2015, ongoing).

The third stage of ocean research is aimed mainly at studying its role in the global processes of matter and energy transfer and its influence on climate formation. The complexity and wide range of research work required extensive international cooperation. The Scientific Committee for Oceanic Research (SCOR), formed in 1957, the Intergovernmental Oceanographic Commission of UNESCO (IOC), which has been operating since 1960, and other international organizations play an important role in coordinating and organizing international research. In 1957-58, a lot of work was carried out within the framework of the first International Geophysical Year (IGY). Subsequently, major international projects were aimed both at the study of individual parts of the AO, for example, EQUALANT I–III (1963–64), Polygon-70 (1970), SICAR (1970–75), POLIMODE (1977–78 ), and A. o. as parts of the World Ocean, for example, TOGA (1985–89), GEOSECS (1973–74), WOCE (1990–96), and others. the role of the ocean in the global carbon cycle and more. other questions. In con. 1980s owls. deep-sea submersibles"Peace» unique ecosystems of geothermal regions of the ocean rift zone were studied. If in 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 ocean ecosystems» (GLOBES, 1995–2010), "Global flows of matter in the ocean» (JGOFS, 1988–2003), " Land-ocean interaction in the coastal zone» (LOICZ), Integral Marine Biogeochemistry and Ecosystem Research (IMBER), Coastal Land-Ocean Interaction (LOICZ, 1993–2015), Ocean Surface-Lower Atmosphere Interaction Study (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 more. etc. The Global Ocean Observing System (GOOS) is being developed. One of the main projects of the WCRP was the program "Climate and Ocean: Unsteadiness, Predictability and Variability" (CLIVAR, since 1995), which was based on the results of TOGA and WOCE. Ros. For many years, scientists have been conducting expeditionary studies of exchange processes at the border of the A. O. and the Arctic Ocean, circulation in the Drake Passage, distribution of cold Antarctic waters along deep-sea faults. Since 2005, the international ARGO program has been operating, in which observations are carried out by autonomous sounding instruments throughout the World Ocean (including AO), and the results are transmitted via artificial Earth satellites to data centers.

In November 2015, for the first time in the last 30 years, Ross made a voyage from Kronstadt to the shores of Antarctica. research vessel of the Baltic Fleet "Admiral Vladimirsky". It made a transition with a length of over 34 thousand sea. miles. Along the route, hydrographic, hydrological, hydrometeorological and radio navigation studies were carried out, information was collected to correct marine navigation charts, navigation manuals and manuals. Having rounded the southern tip of the African continent, the ship entered the marginal seas of Antarctica. He moored near the station "Progress", scientists exchanged with the staff of the station data on monitoring the ice conditions, the melting of the Arctic ice, the weather. The expedition ended on 15.4.2016. In addition to the crew, hydrographers of the 6th Atlantic oceanographic department took part in the expedition. hydrographic expeditions. services of the Baltic Fleet, employees of Ros. state hydrometeorological University, the Institute of the Arctic and Antarctic, etc. The work on the creation of the third part of the Oceanographic Atlas WOCE (The World Ocean Circulation Experiment), dedicated to the Atlantic Ocean, was completed, the presentation of which took place in February 2015 at the IO RAS named after A.I. P. P. Shirshova.

Economic use

A. o. occupies an important place in the world economy among other oceans of our planet. Man's use of the sea, as well as other seas and oceans, follows several basic principles. directions: transport and communications, fishing, mining. resources, energy, recreation.

Transport

Already within 5 centuries A. about. occupies a leading role in maritime transport. 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. o. accounts for approx. 3/5 of the cargo turnover of world shipping, in con. 20th century up to 3.5 billion tons of cargo per year was transported through its waters (according to IOC). OK. 1/2 of the volume of traffic is oil, gas and oil products, followed by general cargo, then iron ore, grain, coal, bauxite and alumina. Ch. the direction of transportation is the North Atlantic, which runs between 35–40 ° N. sh. and 55–60° N. sh. Main shipping routes connect the port cities of Europe, the USA (New York, Philadelphia) and Canada (Montreal). This direction adjoins the sea routes of the Norwegian, Northern and int. seas of Europe (Baltic, Mediterranean and Black). Transported to 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 - South Africa (Cape Town); west-Atlantic: Sev. America, South America is southern Africa. Before the reconstruction of the Suez Canal (1981) b. hours of oil tankers from the Indian basin approx. was forced to go around Africa.

The transportation of passengers occupies an important place in the A. about. since the 19th century, when mass emigration from the Old World to America began. The first steam-sailing vessel, the Savannah, crossed the A. O. for 29 days in 1819. At the beginning. 19th century The Blue Ribbon Prize was established for passenger ships that will cross the ocean the fastest. This prize was awarded, for example, to such famous liners as Lusitania (4 days and 11 hours), Normandie (4 days and 3 hours), Queen Mary (4 days without 3 minutes). The last time the "Blue Ribbon" was awarded to the Amer. liner "United States" in 1952 (3 days and 10 hours). In the beginning. 21st century the duration of a passenger liner flight between London and New York is 5–6 days. Max. passenger transportation through A. o. fell on 1956–57, when more than 1 million people were transported a year; The majority of passengers prefer air transport (the record flight time for the Concorde supersonic airliner on the New York-London route is 2 hours 54 minutes). The first non-stop flight through A. about. committed 14-15.6.1919 English. pilots J. Alcock and A. W. Brown (Newfoundland - Ireland), the first non-stop flight through the A. about. alone (from continent to continent) 20–21.5.1927 – Amer. pilot C. Lindberg (New York - Paris). In the beginning. 21st century practically the entire flow of passengers through A. o. served by aviation.

Connection

In 1858, when there was no radio communication between the continents, through A. o. The first telegraph cable was laid. To con. 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. o. considered the most productive ocean, its biological. resources are exploited by man most intensively. In A. o. fishing and seafood production account for 40–45% of the total world catch (area approx. 25% of the world approx.). The majority of the catch (up to 70%) consists of herring fish (herring, sardines, etc.), cod fish (cod, haddock, hake, whiting, saithe, saffron cod, etc.), flounder, halibut, and sea bass. Production of shellfish (oysters, mussels, squids, etc.) and crustaceans (lobsters, crabs) approx. 8%. According to FAO estimates, the annual catch of fish products in the A. about. is 85–90 million tons, but for most of the fishing areas of the Atlantic, the fish catch reached in the middle. 1990s its maximum and its increase is undesirable. The traditional and most productive fishing area is the north-east. part of the Arctic Ocean, including the North and Baltic Seas (mainly herring, cod, flounder, sprats, and mackerel). In the north-west. area of ​​the ocean, on the Newfoundland banks, cod, herring, flounder, squid, etc. have been harvested for many centuries. In the center. parts of A. o. there is a catch of sardine, horse mackerel, mackerel, tuna, etc. In the south, on the Patagono-Falkland shelf elongated along the latitude, fishing for both warm-water species (tuna, marlin, swordfish, sardines, etc.) and cold-water species (blue whiting, hake , notothenia, toothfish, etc.). Off the coast of and southwest. African catch of sardine, anchovy and hake. In the Antarctic area of ​​the ocean, planktonic crustaceans (krill), marine mammals, fish - notothenia, toothfish, silverfish, etc. are of commercial importance. 20th century in high-latitude sowing. and south. areas of the ocean were active fishing decomp. species of pinnipeds and cetaceans, but in recent decades it has declined sharply due to the depletion of biological. resources and thanks to environmental activities, including intergovernmental ones. agreements to limit their production.

Mineral resources

Miner is being developed more and more actively. wealth of the ocean floor. Deposits of oil and combustible gas have been studied more fully; belong to 1917, when oil production began in the industrial. scales in east. parts of the Maracaibo lagoon (Venezuela). The largest centers of marine production: the Venezuelan Gulf, the Maracaibo lagoon ( Maracaiba oil and gas basin), Mexican Hall. ( Gulf of Mexico oil and gas basin), Hall. Pariah ( Orinok oil and gas basin), Brazilian shelf (Sergipe-Alagoas oil and gas basin), Gulf of Guinea. ( Gulf of Guinea oil and gas basin), Northern m. ( North Sea oil and gas region), etc. Alluvial deposits of heavy minerals are widespread along many coasts. The largest development of alluvial deposits of ilmenite, monocyte, zircon, rutile are carried out off the coast of Florida. Similar deposits are located in the Gulf of Mexico, off the east. US coasts, as well as Brazil, Uruguay, Argentina and the Falkland Islands. On the shelf southwest. Africa is developing coastal marine diamond placers. Gold-bearing placers were found off the coast of Nova Scotia at depths of 25–45 m. In A. o. one of the world's largest iron ore deposits, Wabana, has been explored (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 Gulf of Mexico. large sulfur deposits are being developed Gulf of Mexico sulfur-bearing province. In the coastal zone of the ocean, sand is mined for construction and production of glass, gravel. On the shelf east. US coasts and west. coasts of Africa, phosphorite-bearing sediments have been explored, 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 The use of recreational resources of the ocean is of great importance for the economies of coastal countries. Old resorts are being developed and new ones are being built. Since the 1970s ocean liners are laid down, intended only for cruises, they are distinguished by their large size (displacement of 70 thousand tons or more), an increased level of comfort and relative slowness. Main cruise ship routes A. o. – The Mediterranean and Caribbean Seas and the Mexican Hall. From con. 20 - early. 21st century scientific-tourist and extreme cruise routes are developing, 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 Gulf of Mexico.

Energy

The energy of sea tides 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 the hydrothermal energy of the ocean (temperature difference in surface and deep waters) is also considered promising; the hydrothermal station operates on the coast of Côte d'Ivoire.

Port cities

On the banks of A. o. most of the world's major ports 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 - St. Naser, 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. Ros. port cities do not have direct access to the sea. and are located on the banks int. the seas belonging to its basin: St. Petersburg, Kaliningrad, Baltiysk (Baltic Sea), Novorossiysk, Tuapse (Black Sea).