The Atlantic Ocean is cold. The organic world of the Atlantic Ocean: features and description

The organic world of the Atlantic Ocean depends on temperature, salinity and other indicators characterizing the water area of this part of the Moscow Region. Living conditions for organisms vary significantly from north to south. Therefore, in the Atlantic there are areas rich in natural resources and relatively poor areas, where the number of animal species is in the tens, not hundreds.

The role of living organisms in the natural complex of MO

The organic world of the Atlantic Ocean is significantly influenced by the large extent of the water area from north to south. The diversity of animals and plants is influenced by vast areas of land runoff and other natural factors. The sea, the seabed and the surf are home to thousands of organisms that belong to the different kingdoms of the Earth's nature. Plants and animals are the most important components of the natural complex. They are influenced by climate, composition and properties of water, rocks that make up the bottom. In turn, the organic world of the Atlantic Ocean affects other components of nature:

algae enrich water with oxygen;
respiration of plants and animals leads to an increase in the content of carbon dioxide;
the skeletons of coelenterates form the basis of coral reefs and atolls;
living organisms absorb mineral salts from water, reducing their amount.

The organic world of the Atlantic Ocean (briefly)

Temperature and salinity values are critical for microscopic living things that make up plankton, as well as algae. These indicators are important for nekton - animals that swim freely in the water column. The features of the relief of the shelf and ocean floor determine the vital activity of benthic organisms - benthos. This group includes many coelenterates and crustaceans. There is whole line features of the species composition that characterize the organic world of the Atlantic Ocean. The photo of the seabed, presented below, makes it possible to verify the diversity of benthos in subtropical and tropical latitudes. Fish-rich waters are confined to areas of intensive plankton reproduction in temperate and hot zones. A variety of seabirds and mammals are also observed in these regions. High latitudes in the north and south are characterized by the predominance of birds that feed on the surface of the ice-free water, and nest colonies are built on the coast.

Phytoplankton

They constitute an important part of plankton. This group includes diatoms, blue-green, flagellates and other tiny living organisms capable of photosynthesis. They inhabit the water column up to 100 m deep, but the highest density is observed in the first 50 m from its surface. Intensive solar radiation in the warm season leads to the rapid development of phytoplankton - "bloom" of water in the temperate and polar latitudes of the Atlantic Ocean.

Large plants

Photosynthetic green, red, brown algae and other representatives of the MO flora are an important part of the natural complex. Thanks to plants, the entire organic world of the Atlantic Ocean receives oxygen for respiration and nutrients. The list of benthic vegetation or phytobenthos includes not only algae, but also representatives of angiosperms that have adapted to living in salt water, for example, the genera Zoster, Posidonia. These "sea grasses" prefer the soft soils of the sublittoral, and form underwater meadows at depths of 30 to 50 m.

Typical representatives of the flora of the continental shelf in the cold and temperate zones on both sides of the equator are kelp. They attach to bottom rocks, single stones. Marine vegetation in the hot zone is poorer due to high temperatures and significant insolation.
The economic value of algae:

brown (kelp) - eaten, used to obtain iodine, potassium and algin;
red algae - raw material for the food and pharmaceutical industries;
brown sargassum algae is a source of algin production.

Zooplankton

Phytoplankton and bacteria are food for herbivorous microscopic animals. Floating freely in the water column, they make up zooplankton. It is based on the smallest representatives of crustaceans. The larger ones are combined into meso- and macroplankton (comb jellies, siphonophores, jellyfish, shrimps and small fish).

Necton and benthos

There is a large group of living organisms in the ocean that are able to withstand the pressure of water and move freely in its thickness. Such abilities are possessed by marine animals of medium and large sizes.

Crustaceans. Shrimp, crabs and lobsters belong to this subtype.
Shellfish. Typical representatives of the group are scallops, mussels, oysters, squid and octopuses.
Fishes. The genera and families of this superclass are the most numerous - anchovies, sharks, flounder, sprat, salmon, sea bass, capelin, pollock, haddock, halibut, sardines, herring, mackerel, cod, tuna, hake.
Reptiles. A few representatives are sea turtles.
Birds. Penguins, albatrosses, petrels forage for food in the water.
Marine mammals. Highly organized animals - dolphins, whales, seals, seals.

The basis of benthos is made up of animals that lead an attached lifestyle at the bottom, for example, coelenterates (coral polyps).

Features of plants and animals of the Atlantic

In the northern and southern parts of the basin, the presence of different species and genera is noted in the fauna.
There are few plankton species, but the total mass reaches impressive values, especially in the temperate climatic zone. Foraminifera, pteropods and (krill) predominate.
High biological productivity is a feature that characterizes the features of the organic world of the Atlantic Ocean. It is distinguished by a significant density of life in shallow waters near Newfoundland Island, waters to the southwest and northwest of the African coast, marginal seas and the eastern shelf of the USA and South America.
The tropical zone, as noted above, is an unfavorable area for phytoplankton.
The productivity of the Atlantic Ocean nekton on the shelf and part of the continental slope is higher than in similar areas of neighboring oceans. Fish that feed on phyto- and zooplankton (anchovies, herring, mackerel, horse mackerel and others) predominate. In open waters, tuna are of commercial importance.
The species richness of mammals is one of the features of the fauna of the Atlantic Ocean. In the past century, they have undergone significant extermination, the number has decreased.
Coral polyps are not as diverse as in the Pacific Basin. There are few sea snakes and turtles.

There are various factors that explain many of the listed features that characterize the organic world of the Atlantic Ocean. The conclusion from all that has been said above suggests the following: the reasons for the differences are associated with the small width of the Atlantic in the hot zone, expansion in the temperate and circumpolar regions. On the contrary, the Pacific and Indian oceans have the greatest extent in the tropical zone. Another factor that influenced the relative poverty of the Atlantic in thermophilic animals is the influence of the last glaciation, which caused a significant cooling in the Northern Hemisphere.

The organic world of the Atlantic Ocean: fishing objects

The temperate and tropical latitudes in the Northern and Southern Hemispheres are rich in life. Among the fish species of commercial importance are anchovies, pollock, tuna, cod, hake and others. Mammals are being hunted: whales and fur seals. Other types of biological resources are represented by molluscs, crustaceans, brown and red algae. Ocean plants are used for pet food and industrial processing. Most shellfish are delicacies, prized in the cuisine of many countries (oysters, squid, octopus. The same characteristic can be given to crustaceans, including lobster, shrimp and crabs.

Fishing and seafood production is more intensive on the shelf and in the area of the continental slopes. But in recent decades, areas of the water area that previously experienced not such a strong anthropogenic influence have been involved in economic circulation. Therefore, environmental problems are aggravated not only in coastal areas, but also in the entire ocean.

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

Physico-geographical sketch

General information

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

A. about. stretches from north to south for almost 15 thousand km, its smallest width is approx. 2830 km in the equatorial part, the largest - 6700 km (along the parallel of 30 ° N). Area A. o. with seas, bays and straits 91.66 million km 2, without them - 76.97 million km 2. The volume of waters is 329.66 million km 3, without seas, bays and straits - 300.19 million km 3. Wed depth 3597 m, maximum - 8742 m (trough Puerto Rico). The most easily accessible for development the 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 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 (the zone of the continental slope) 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 inland - Baltic, Azov, Black, Marmara and Mediterranean (in the latter, in turn, the seas are distinguished: Adriatic, Alboran, Balearic, Ionian, Cypriot, Ligurian, Tyrrhenian, Aegean); inter-island - Irish and domestic seas west. the coast of Scotland; marginal - Labrador, North, Sargassovo, Caribbean, Scotia (Scotia), Weddell, Lazarev, west. part of Riiser-Larsen (see separate articles on the seas). The largest bays of the ocean: Biscay, Bristol, Guinea, Mexican, Maine, St. Lawrence. The most important straits of the ocean: Great Belt, Bosphorus, Gibraltar, Dardanelles, Danish, Davisov, Drake, Øresund (Sound), Cabota, Kattegat, Kerch, English Channel (including Pas-de-Calais), Small Belt, Messinsky, Skagerrak , Florida, Yucatan.

Islands

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

The shores

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

Bottom relief

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

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

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

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

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

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

Geological structure

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

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

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

Bottom sediments

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

Climate

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

Hydrological regime

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

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

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

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

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

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

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

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

Flora and fauna

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

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

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

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

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

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

Research history

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

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

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

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

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

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

Economic use

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

Transport

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

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

Connection

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

Fishing

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

Mineral resources

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

Recreational resources

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

Energy

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

Port cities

On the shores of A. about. most of the 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-Saint Nazer, Copenhagen; all in. 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, Abidjan, Cape Town. Grew up. port cities do not have direct access to the Atlantic Ocean. and are located on the banks of the ext. seas related to its basin: St. Petersburg, Kaliningrad, Baltiysk (Baltic Sea), Novorossiysk, Tuapse (Black Sea).

ATLANTIC OCEAN (Latin name Mare Atlanticum, Greek? Τλαντ? Σ - meant the space between the Strait of Gibraltar and the Canary Islands, the entire 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 sketch. 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 to Cape Brewster, through the Danish Strait to Cape Reidinupur on Iceland, along its coast to Cape Gerpir (Terpir), then to the Faroe Islands, then to the Shetland Islands and 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 North America and South America. The border of the Atlantic Ocean with the Indian Ocean is drawn along a line running 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 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 South Atlantic Ocean is sometimes called the Atlantic Sector of the Southern Ocean, drawing the boundary along the subantarctic convergence zone (approximately 40 ° S latitude). In some works, the division of the Atlantic Ocean into the North and South Atlantic Oceans is proposed, but it is more customary 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; 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 waters 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 (trench in Puerto Rico). The most easily accessible ocean shelf zone (with depths of up to 200 m) occupies about 5% of its area (or 8.6% if we take into account seas, bays and straits), its area is larger than in the Indian and Pacific Oceans, and much less than in the Arctic Ocean. Areas with depths from 200 m to 3000 m (the zone of the continental slope) 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 the map.

Seas... In the basin of the Atlantic Ocean there are numerous seas, which are divided into: the internal ones - the Baltic, Azov, Black, Marmara and Mediterranean (in the latter, in turn, the seas are distinguished: Adriatic, Alboran, Balearic, Ionian, Cypriot, Ligurian, Tyrrhenian, Aegean) ; inter-island - the Irish and inland seas of the west coast of Scotland; marginal - Labrador, Severnoye, Sargassovo, Caribbean, Scotia (Scotia), Weddell, Lazarev, western part of Riiser-Larsen (see separate articles on the seas). The largest bays of the ocean: Biscay, Bristol, Guinea, Mexican, Maine, Saint Lawrence.

Islands... Unlike other oceans, the Atlantic Ocean has few seamounts, guyots and coral reefs, and there are no coastal reefs. The total area of the islands of the Atlantic Ocean is about 1070 thousand km 2. 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 (Tierra del Fuego, Oste, Navarino ), Marajo, Sicily, Sardinia, Lesser Antilles, Falkland (Malvinas), Bahamas, etc. In the open ocean there are small islands: Azores, Sao Paulo, Ascension, Tristan da Cunha, Bouvet (on the Mid-Atlantic ridge) and dr.

The shores... The coastline in the North Atlantic Ocean is heavily indented (see also the article Shore), almost all large inland seas and bays are located here, in the South Atlantic, the shores are weakly indented. The shores of Greenland, Iceland and the coast of Norway are predominantly of tectonic-glacial division of the fjord and fiard types. Further south, in Belgium, they give way to sandy shoals. The Flanders coast is mainly of artificial origin (coastal dams, polders, canals, etc.). The shores of the island of Great Britain and the islands of Ireland are abrasion-cove, high limestone cliffs alternate with sandy beaches and muddy drylands. On the Cherbourg peninsula there are rocky shores, sandy and gravel beaches. The northern coast of the Iberian Peninsula is composed of rocky rocks, to the south, off the coast of Portugal, sandy beaches prevail, often fencing off lagoons. Sandy beaches also border the shores of Western Sahara and Mauritania. To the south of Cape Zelyoniy 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 bank with a significant number of spits and lagoons. In southwestern Africa, there are accumulative, less often abrasion-bay shores with extensive sandy beaches. The shores of southern Africa of the abrasion-bay type are composed of hard crystalline rocks. The shores of Arctic Canada are abrasive, with high cliffs, glacial deposits and limestones. In eastern Canada and northern St Lawrence Bay, there are intensely eroded limestone and sandstone cliffs. In the west and south of the Gulf of St. Lawrence, there are wide beaches. On the shores of the Canadian provinces of Nova Scotia, Quebec, Newfoundland - outcrops of hard crystalline rocks. From about 40 ° north latitude to Cape Canaveral in the USA (Florida) there is an alternation of leveled accumulative and abrasion types of shores, composed of loose rocks. The Gulf Coast is low-lying, fringed by Florida mangroves, Texas sand barriers, and Louisiana delta shores. On the Yucatan Peninsula - cemented beach sediments, to the west of the peninsula - an alluvial-marine plain with coastal ramparts. On the Caribbean coast, abrasion and accumulation areas alternate with mangrove swamps, coastal barriers and sandy beaches. To the south of 10 ° north latitude, accumulative banks are widespread, composed of material carried out from the mouth of the Amazon River and other rivers. In the north-east of Brazil there is a sandy coast with mangrove thickets, interrupted by river estuaries. From Cape Kalkanyar to 30 ° S latitude, there is a high abrasion-type coastline. To the south (off the coast of Uruguay) there is an abrasion-type coast, composed of clays, loesses and sand and gravel deposits. In Patagonia, the shores are represented by high (up to 200 m) cliffs with loose sediments. The shores of Antarctica are 90% composed of ice and belong to the ice and thermal abrasion type.

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

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

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

In the middle part of the floor of the Atlantic Ocean is the largest mountain system of the Mid-Atlantic Ridge. It stretches from Iceland to Bouvet Island for 18,000 km. The width of the ridge is from several hundred to 1000 km. 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-water basins separated by bottom uplifts. In the western part of the Atlantic Ocean, the following 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 Som, Hatteras and Nares abyssal plains; Guiana (4500-5000 m) with the plains of Demerara and Ceara; Brazilian Basin (5000-5500 m) with the Abyssal Plain of Pernambuco; Argentinian (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), Cape Verde (up to 6000 m), Sierra Leone (about 5000 m), Guinea (over 5000 m) ), Angolan (up to 6000 m), Cape (over 5000 m) with the abyssal plains of the same name. In the south is the African-Antarctic Basin with the Weddell Abyssal Plain. The bottom of the deep-water basins at the foot of the Mid-Atlantic Ridge is occupied by a zone of abyssal hills. The hollows are separated by the uplifts Bermuda, Rio Grande, Rockall, Sierra Leone, and others, the Kitovy, Newfoundland, and other ridges.

Seamounts (isolated conical elevations with a height of 1000 m and more) on the floor of the Atlantic Ocean are concentrated mainly in the zone of the Mid-Atlantic Ridge. In the deep-water part, large groups of seamounts are found north of Bermuda, in the Gibraltar sector, at the northeastern bulge of South America, in the Gulf of Guinea and west of South Africa.

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

Geological structure. The Atlantic Ocean emerged as a result of the breakup of the late Paleozoic supercontinent Pangea during the Jurassic. It is characterized by a sharp predominance of passive outskirts. The Atlantic Ocean is bordered by adjacent continents along transform faults south of Newfoundland Island, along the northern coast of the Gulf of Guinea, along the Falklands Submarine Plateau and the Agulhas Plateau in the southern part of the ocean. Active margins are observed in some areas (in the area of the Lesser Antilles arc and the arc of the South Sandwich Islands), where subsidence occurs with subduction (subduction) of the Atlantic Ocean crust. The limited extent of the Gibraltar subduction zone has been identified in the Gulf of Cadiz.

In the Mid-Atlantic Ridge, the bottom is spreading (spreading) and the formation of the oceanic crust at a rate of up to 2 cm per year. High seismic and volcanic activity is characteristic. To the north of the Mid-Atlantic Ridge, paleospreading ridges branch off into the Labrador Sea and the Bay of Biscay. In the axial part of the ridge, there is a pronounced rift valley, which is absent in the extreme south and in most of the Reykjanes ridge. Within its limits there are volcanic uplifts, frozen lava lakes, basaltic lava flows in the form of pipes (pillubasalts). In the Central Atlantic, fields of metalliferous fluids have been discovered, many of which form hydrothermal edifices 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 taluses and landslides, consisting of boulders and rubble of rocks of the oceanic crust (basalts, gabbros, 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 influx of clastic material from the land. The age of the oceanic crust increases in the same direction, reaching the Early Cretaceous (north of Florida in the Middle Jurassic). The 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 by 1700 km). The largest transform faults (Vima, São Paulo, Romansh, etc.) are accompanied by deep incisions (grooves) on the ocean floor. They reveal the entire section of the oceanic crust and partly of the upper mantle; widely developed protrusions (cold intrusions) of serpentinized peridotites, forming ridges, elongated along the strike of the faults. Many transform faults are transoceanic, or main (demarcation) faults. The Atlantic Ocean contains the so-called intraplate uplifts, represented by submarine plateaus, aseismic ridges and islands. They have a thick oceanic crust and are mainly of volcanic origin. Many of them were formed as a result of the action of mantle jets (plumes); some arose 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, pair of Sierra and Sierra Leone uplifts, Rio Grande and Whale Ridge, Bermuda Uplift, Cameroon group of volcanoes, etc. In the Atlantic Ocean there are intraplate uplifts of non-volcanic nature, including the Rockall underwater plateau, separated from the British Isles by the trough of the same name. The plateau is a microcontinent that split off from Greenland in the Paleocene. Another microcontinent also split off from Greenland is the Hebrides Massif in northern Scotland. Submarine marginal plateaus off the coast of Newfoundland (Great Newfoundland, Flemish Cap) and off the coast of Portugal (Iberian) were cut off from the continents as a result of rifting in the late Jurassic - early Cretaceous.

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 sediments on the American and North African margins of the ocean. In the late Jurassic - early Cretaceous, the Antarctic segment began to open. In the Early Cretaceous, spreading was experienced by the Southern Segment in the South Atlantic and the Newfoundland-Iberian Segment in the North Atlantic. Opening of the Labrador-British segment began in the late Early Cretaceous. At the end of the Late Cretaceous, the Labrador Basin Sea arose here as a result of spreading on the side axis, which continued until the Late Eocene. The North and South Atlantic united in the middle Cretaceous - Eocene during the formation of the Equatorial segment.

Bottom sediments ... The thickness of the strata of modern bottom sediments ranges from several meters in the zone of the ridge of the Mid-Atlantic Ridge to 5-10 km in the zones of transverse faults (for example, in the Romanche trench) and at the foot of the continental slope. In deep-water basins, their thickness is from several tens to 1000 m. 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 of up to 200 m) to silts. At depths of more than 4500-4700 m, calcareous silts are replaced by polygenic and siliceous planktonic sediments. The former occupy about 28.5% of the ocean floor area, lining the bottoms of the basins, and are represented by deep-sea red 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, of which diatom oozes (formed by the skeletons of diatoms) are the most widespread. They are common off the coast of Antarctica and on the shelf of South-West Africa. Radiolarian oozes (formed by the skeletons of radiolarians) are found mainly in the Angola Basin. Terrigenous sediments of various compositions (gravel-pebble, sandy, clayey, etc.) are developed along the coast of the ocean, on the shelf and partly on the continental slopes. The composition and thickness of terrigenous sediments are determined by the bottom topography, the activity of the influx of solid material from the land and the mechanism of their transfer. Glacial precipitation carried by icebergs is widespread along the coast of Antarctica, Greenland, Newfoundland, and the Labrador Peninsula; composed of poorly sorted detrital material with the inclusion of boulders, mostly in the south of the Atlantic Ocean. In the equatorial part, sediments (from coarse sand to silt) formed from pteropod shells are often found. Coral sediments (coral breccias, pebbles, sands and silts) are found in the Gulf of Mexico, the Caribbean and off the northeastern coast of Brazil; their maximum depth is 3500 meters. Volcanic sediments are developed near volcanic islands (Iceland, Azores, Canary, Cape Verde, etc.) and are represented by fragments of volcanic rocks, slag, pumice, volcanic ash. Modern chemogenic sediments are found on the Big Bahamas Bank, in the Florida-Bahamas, Antilles regions (chemogenic and chemogenic-biogenic carbonates). Ferromanganese nodules are found in the depressions of the North American, Brazilian, and Cape Verde; 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 exposed 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, and in the southern part of the Weddell Sea, a temperature of -32.3 ° C was recorded. 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 there are 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 supports steady eastward winds (trade winds) in tropical and equatorial latitudes, and strong westerly winds in temperate latitudes, which have been called "roaring forties" by sailors. Strong winds are typical for the Bay of Biscay. In the equatorial region, the interaction of the northern and southern baric systems leads to frequent tropical cyclones (tropical hurricanes), the greatest activity of which is observed 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 often falls and strong clouds are observed. Thus, over 2000 mm of precipitation falls on the equator per year, in temperate latitudes - 1000-1500 mm. In areas of high pressure (subtropics and tropics), the amount of precipitation decreases to 500-250 mm per year, and in areas adjacent to the desert shores of Africa and in the South Atlantic maximum - to 100 mm or less per year. In areas where warm and cold currents meet, fogs are frequent, for example, in the 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 discharge 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 balance of fresh water in 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 groundwater runoff (21 thousand km 3 / year) and melting of ice and icebergs in the Arctic and Antarctic (about 3 thousand km 3 / year). The water balance deficit is compensated by the influx of water, mainly from the Pacific Ocean, 3470 thousand km 3 / year flows through the Drake Passage with the course of the Western Winds, and only 210 thousand km 3 / year leave the Atlantic Ocean to the Pacific Ocean. 260 thousand km 3 / year flows from the Arctic Ocean through numerous straits into the Atlantic Ocean and 225 thousand km 3 / year of Atlantic waters flows back into the Arctic Ocean. The water balance with the Indian Ocean is negative, 4976 thousand km 3 / year are carried out into the Indian Ocean with the course of the Western 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 ocean waters as a whole is 4.04 ° С, and of surface waters 15.45 ° С. The distribution of water temperature on the surface is asymmetric relative 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 North, the warmest waters of the open part of the ocean (thermal equator) are located between 5 and 10 ° N latitude, that is, they are displaced north of the geographic equator. The peculiarities of large-scale water circulation lead to the fact that the surface water temperature near the western coast of the ocean is approximately 5 ° C higher than that of the eastern one. The most warm temperature water (28-29 ° С) on the surface in the Caribbean Sea and the Gulf of Mexico in August, the lowest - off the coast of Greenland, Baffin Island, Labrador Peninsula and Antarctica, south of 60 °, where even in summer the water temperature does not rise above 0 ° WITH. The water temperature in the layer of the main thermocline (600-900 m) is about 8-9 ° C, deeper, in intermediate waters, it drops on average to 5.5 ° C (1.5-2 ° C in Antarctic intermediate waters). In deep waters, the average water temperature is 2.3 ° C, in bottom waters - 1.6 ° C. At the very bottom, the water temperature rises slightly due to the geothermal heat flux.

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 ‰, of surface waters 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 input with atmospheric precipitation, the lowest (6-20 ‰) in the estuaries of large rivers flowing into the ocean. From 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 salinity is observed at depths of 600-800 m. The waters of the North Atlantic Ocean are characterized by a deep maximum salinity (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, the bottom, occupying the deepest depressions of the ocean, 34.7-34.8 ‰ and 1.6 ° C, respectively.

Density... The density of water depends on temperature and salinity, and for the Atlantic Ocean, temperature is more important in the formation of the field of water density. The waters with the lowest density are located in the equatorial and tropical zones with high water temperatures and a strong influence of the runoff 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 - 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 North Atlantic Ocean, first-year ice forms mainly in the inland seas of temperate latitudes, perennial ice is carried out from the Arctic Ocean. The boundary of the distribution of the ice cover in the North Atlantic Ocean changes significantly; in winter, pack ice can reach 50-55 ° north latitude in different years. There is no ice in summer. The boundary of Antarctic perennial ice in winter runs at a distance of 1600-1800 km from the coast (approximately 55 ° South latitude), in summer (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 Antarctic glaciers is estimated at 1.6 · 10 12 tons per year, the main source of which is the Filchner Ice Shelf in the Weddell Sea. Icebergs with a total mass of 0.2-0.3 x 10 12 tons per year come from the glaciers of the Arctic into the Atlantic Ocean, mainly from the Jacobshavn Glacier (in the area of Disko Island off the western coast of Greenland). The average lifespan of Arctic icebergs is about 4 years, Antarctic icebergs are slightly longer. The boundary of the distribution of icebergs in the northern part of the ocean is 40 ° north latitude, but in some cases they were observed up to 31 ° north latitude. In the southern part, the boundary runs at 40 ° S, in the central part of the ocean and at 35 ° S on the western and eastern periphery.

Currents... The water circulation in the Atlantic Ocean is subdivided into 8 quasi-stationary oceanic gyres located almost symmetrically relative to the equator. Tropical anticyclonic, tropical cyclonic, subtropical anticyclonic, subpolar cyclonic oceanic gyres are located in the Northern and Southern Hemispheres from low to high latitudes. Their boundaries, as a rule, are the main oceanic currents. The warm current of the Gulf Stream begins at the Florida Peninsula. Taking in the waters of the warm Antilles Current and the Florida Current, the Gulf Stream is directed to the northeast and at high latitudes is divided into several branches; the most significant of them are the Irminger Current, which carries warm waters to the Strait of Davis, the North Atlantic Current, and the Norwegian Current, which flows into the Norwegian Sea and further to the northeast, along the coast of the Scandinavian Peninsula. A cold Labrador Current emerges from the Davis Strait towards them, the waters of which can be traced off the coast of America to almost 30 ° north latitude. The cold East Greenland Current flows from the Danish Strait into the ocean. In the low latitudes of the Atlantic Ocean, warm North trade currents and South trade winds are directed from east to west, between them, at about 10 ° north latitude, from west to east there is an inter-trade countercurrent, which is active mainly in summer in the northern hemisphere. From the South trade winds, the Brazilian current is separated, which runs from the equator and up to 40 ° south latitude along the coast of America. The northern branch of the South Tradewinds forms the Guiana Current, which is directed from south to northwest until it joins the waters of the North Tradewinds. Off the coast of Africa, from 20 ° north latitude to the equator, the warm Guinean Current passes; in the summertime, the Inter-trade countercurrent is connected to it. In the southern part, the Atlantic Ocean is crossed by the cold West Winds Current (Antarctic Circumpolar Current), which enters the Atlantic Ocean through the Drake Passage, descends to 40 ° S latitude and exits into the Indian Ocean south of Africa. From it are separated the Falkland Current, which reaches 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. 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 North Trade Winds.

Deep water circulation... The deep circulation and structure of the waters of the Atlantic Ocean are formed as a result of changes in their density during cooling of waters or in zones of mixing of waters of different origins, where the density increases as a result of mixing of waters with different salinity and temperature. 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 subpolar regions and are located at depths from 400-500 m to 1000-1500 m, with temperatures from 3 to 7 ° C and salinity of 34.0-34.9 ‰. The circulation of subsurface and intermediate waters is generally anticyclonic in nature. Deep waters form 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 ° С, salinity is 34.64-34.89 ‰. Waters formed in high northern 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. 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 up in the North Pacific Ocean.

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

Flora and fauna... The great length of the Atlantic Ocean, a variety of climatic conditions, a significant influx of fresh water and large upwellings provide a variety of living conditions. In total, about 200 thousand species of plants and animals live in the ocean (of which there are about 15,000 species of fish, about 600 species of cephalopods, about 100 species of whales and pinnipeds). Life is very unevenly distributed in the ocean. There are three main types of zoning in the distribution of life in the ocean: latitudinal, or climatic, vertical and circumcontinental zoning. 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 ones.

Planktonic organisms (phytoplankton and zooplankton) are the basis of the food chain in the ocean, the bulk of them live in the upper zone of the ocean, where light penetrates. The greatest biomass of plankton is in high and temperate latitudes during spring-summer flowering (1-4 g / m 3). During the year, the biomass can change by a factor of 10-100. The main types of phytoplankton are diatoms, zooplankton - copepods and euphausids (up to 90%), as well as bristle-mandibular, hydromedusa, comb jellies (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 Gulfs of Mexico and Guinea. Phytoplankton is represented mainly by coccolithins and peridineas, the latter can develop in coastal waters in huge quantities, causing the catastrophic phenomenon of the "red tide". Zooplankton of low latitudes is represented by copepods, chaetomaxillary, hyperids, hydromedusae, siphonophores and other species. There are no clearly pronounced dominant species of zooplankton at low latitudes.

Benthos is represented by large algae (macrophytes), which mostly grow on the bottom of the shelf zone, up 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 attachment to the bottom, the absence or moderate velocities of bottom currents, etc. In the high latitudes of the Atlantic Ocean, the main part of phytobenthos is made up of kelp and red algae. In the temperate zone of the North Atlantic Ocean, along the American and European coasts, there are brown algae (fucus and ascophyllum), kelp, desmarestia and red algae (furcellaria, anfeltia, etc.). Zostera is common on soft soils. The temperate and cold zones of the southern Atlantic Ocean are dominated by brown algae. In the tropical zone in the littoral zone, due to strong heating and intense insolation, vegetation on the ground is practically absent. A special place is occupied by the ecosystem of the Sargasso Sea, where floating macrophytes (mainly of three species of Sargassum algae) form clusters on the surface in the form of ribbons ranging 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 distance from the coast, the number of species decreases. The cold and temperate zones are characterized by: fish - various types of cod, haddock, pollock, herring, flounder, catfish, conger eel, etc., herring and polar sharks; among mammals - pinnipeds (harp seal, hooded seal, etc.), various species of cetaceans (whales, sperm whales, killer whales, grind, bottlenose, etc.).

There is a great deal of similarity between the faunas of the temperate and high latitudes of both hemispheres. At least 100 animal species are bipolar, that is, they are characteristic of both temperate and high belts. The tropical zone of the Atlantic Ocean is characterized by: fish - various sharks, flying fish, sailboats, various types of tuna and glowing anchovies; from animals - sea turtles, sperm whales, river dolphin inia; cephalopods are also numerous - various types of squid, octopus, 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 voyages and the first nautical charts. Their voyages reached the Iberian Peninsula, England and the mouth of the Elbe. In the 4th century BC Piteas (Pytheas), while sailing in the North Atlantic, determined the coordinates of a number of points and described the tidal phenomena in the Atlantic Ocean. The Canary Islands are mentioned in the 1st century AD. In the 9-10th centuries, the Normans (Eirik Raudie and his son Leif Erikson) crossed the ocean, visited Iceland, Greenland, Newfoundland and explored the shores of North America up to 40 ° north latitude. In the era of the Great geographical discoveries(mid-15th - mid-17th century) seafarers (mainly 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. Dias (1487), the Genoese J. 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 first passed from the Atlantic Ocean to the Pacific Ocean by the strait, later named after him. In the 16-17 centuries, the Atlantic coast of North America was intensively explored (the British J. Davis, 1576-78, G. Hudson, 1610, W. Baffin, 1616, and other navigators, whose names can be found on the map of the ocean). The Falkland Islands were discovered in 1591-92. The southern shores of the Atlantic Ocean (mainland 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 H. 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 developing new methods of exploring depths, new technology and new approaches to organizing work. For the first time, bathometers, deep-sea thermometers, thermo-depth meters, deep-water trawls and dredges are used. Among the most significant can be noted the 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 direction of J. Ross (1840-43); American - on "Seiklab" and "Arctic" under the leadership of MF Mori (1856-57). Real comprehensive oceanographic studies of the ocean began with an expedition on board the British corvette Challenger, led by C.W. Thomson (1872-76). Significant expeditions that followed her were carried out on the vessels 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 headed 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. In 1903, work began on the "standard" sections in the North Atlantic under the leadership of the International Council for the Study of the Sea (ICES) - the first international oceanographic scientific organization that existed before the 1st World War.

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

After World War II, an echo sounder was widely used to study the ocean floor. This allowed us to get a real picture of the topography of the ocean floor. In the 1950s-70s, comprehensive geophysical and geological studies of the Atlantic Ocean were carried out and the features of the topography of its bottom and tectonics, the structure of the sedimentary stratum, were established. Many large forms of bottom topography have been identified (underwater ridges, mountains, trenches, fault zones, vast basins and uplifts), 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 the transfer of matter and energy, the influence on the formation of the climate. 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 at UNESCO (IOC), operating since 1960, and other international organizations play an important role in the coordination and organization of international research. In 1957-58, extensive work was carried out within the framework of the first International Geophysical Year (IGY). Subsequently, large international projects are aimed not only at studying individual parts of the Atlantic Ocean (for example, EQUALANT I-III; 1962-1964; Polygon, 1970; CICAR, 1970-75; POLYMODE, 1977; TOGA, 1985-89), but also at its study as a part of the World Ocean (GEOSECS, 1973-74; WOCE, 1990-96, and others). 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, Soviet deep-sea vehicles Mir studied the unique ecosystems of the geothermal regions of the rift zone of the ocean. If at the beginning of the 1980s there were about 20 international ocean research projects, then by the 21st century there were more than 100. The largest programs: the International Geosphere-Biosphere Program (since 1986, 77 countries participate), it includes the projects Interaction land - ocean in the coastal zone ”(LOICZ),“ Global Fluxes of Matter in the Ocean ”(JGOFS),“ Dynamics of Global Oceanic 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, like other seas and oceans, goes in several main directions: transport and communications, fishing, mining of mineral resources, energy, and recreation.

Transport... For 5 centuries, the Atlantic Ocean has played 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. The Atlantic Ocean accounts for about 3/5 of the world's shipping traffic; at the end of the 20th century, up to 3.5 billion tons of cargo was transported across its waters per year (according to the IOC). Oil, gas and oil products account for about 1/2 of the traffic volume, 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). This direction is adjacent to the sea routes of the Norwegian, North and inland seas of Europe (Baltic, Mediterranean and Black). Mainly raw materials (coal, ores, cotton, timber, etc.) and general cargo are transported. Other important directions of transportation - South Atlantic: Europe - Central (Panama, etc.) and South America (Rio de Janeiro, Buenos Aires); East Atlantic: Europe - southern Africa (Cape Town); West Atlantic: North America, South America - southern Africa. Before the reconstruction of the Suez Canal (1981), most of the oil tankers from the Indian Basin were forced to sail around Africa.

Passenger transportation has been an important place in the Atlantic Ocean since the 19th century, when mass emigration from the Old World to America began. The first steam-sailing vessel "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 faster. This prize was awarded, for example, to such famous liners as "Lusitania" (4 days and 11 hours), "Normandy" (4 days and 3 hours), "Queen Mary" (4 days without 3 minutes). The last time the "Blue Ribbon" was assigned to the American 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 was 5-6 days. The maximum passenger traffic across the Atlantic Ocean occurred in 1956-57, when more than 1 million people were transported a year, in 1958 the volume of passenger traffic by air was equal to sea transport, and then an increasing number of passengers prefer air transport (the record flight time of a supersonic liner "Concorde" on the route New York - London - 2 hours 54 minutes). The first non-stop flight across the Atlantic Ocean was made on 14-15 June 1919 by the English pilots J. Alcock and A. W. Brown (Newfoundland Island - the island of Ireland), the first non-stop flight across the Atlantic Ocean alone (from continent to continent) 20-21 May 1927 - American pilot C. Lindbergh (New York - Paris). At the beginning of the 21st century, almost all the flow of passengers across the Atlantic Ocean is served by aviation.

Connection... In 1858, when there was no radio communication between 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 were operating 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 humans. 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 herring (herring, sardines, etc.), cod (cod, haddock, hake, whiting, pollock, navaga, etc.), flounder, halibut, sea bass. The catch of molluscs (oysters, mussels, squid, 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, fish catches reached their maximum in the mid-1990s and an 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). V northwest region ocean, on Newfoundland banks, cod, herring, flounder, squid, etc. have been caught for many centuries. In the central part of the Atlantic Ocean, there is a catch of sardine, horse mackerel, mackerel, tuna, etc. both warm-water species (tuna, marlins, swordfish, sardines, etc.) and cold-water species (blue whiting, hake, notothenia, toothfish, etc.). Off the coast of western and south-western Africa, catch of sardines, anchovy and hake. In the Antarctic region of the ocean, planktonic crustaceans (krill), marine mammals are of commercial importance, from fish - notothenia, toothfish, silverfish, etc. For decades, it has sharply decreased due to the depletion of biological resources and thanks to environmental protection measures, including intergovernmental agreements on limiting their production.

Mineral resources... The mineral wealth of the ocean floor is being exploited more and more actively. Oil and combustible gas deposits have been studied more fully; the first mentions of their exploitation in the Atlantic Ocean basin date back to 1917, when oil production began on an industrial scale in the eastern part of the Maracaibo lagoon (Venezuela). The largest centers of offshore production: the Gulf of Venezuela, the Maracaibo lagoon (Maracaibo oil and gas basin), the Gulf of Mexico (the Gulf of Mexico oil and gas basin), the Gulf of Paria (the Orinoco oil and gas basin), Brazilian shelf (Sergipe-Alagoas oil and gas basin) ), The North Sea (the North Sea is an oil and gas region), etc. Placer deposits of heavy minerals are widespread along many coasts. The largest development of placer deposits of ilmenite, monocyte, zircon, rutile is carried out off the coast of Florida. Such 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 southwest Africa, offshore diamond deposits are being developed. Gold-bearing placers were discovered off the coast of Nova Scotia at depths of 25-45 m. One of the world's largest iron ore deposits, Wabana (in the Conception Bay off the coast of Newfoundland), has been explored in the Atlantic Ocean; 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. 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 the production of glass, 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. At the bottom of the North American Basin and on the Blake Plate, large fields of ferromanganese nodules have been found; their total reserves in the Atlantic Ocean are estimated at 45 billion tons.

Recreational resources... Since the second half of the 20th century, the use of the recreational resources of the ocean has been of great importance for the economies of coastal countries. Old resorts are developing and new ones are being built. Since the 1970s, ocean liners designed only for cruises have been laid, 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 the Atlantic Ocean cruise ships are the Mediterranean and the Caribbean and the Gulf of Mexico. From the late 20th - early 21st centuries, 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 Canary Islands, Azores, Bermuda, the Caribbean Sea and the Gulf of Mexico.

Energy... The energy of the tides of the Atlantic Ocean is estimated at about 250 million kWh. In the Middle Ages, tidal 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 hydrothermal energy of the ocean (the difference in temperature in surface and deep waters) is also considered promising; a hydrothermal station operates on the coast of Cote d'Ivoire.

Port cities... 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 Saint 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, Abi-jan, Cape Town. Russian port cities do not have direct access to the Atlantic Ocean and are located on the shores of the 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 / Otv. editor D. E. Gershanovich. M., 1986; Broeker W. S. The great ocean conveyor // Oceanograpy. 1991. Vol. 4. No. 2; Pushcharovsky Yu. M. Atlantic tectonics with elements of nonlinear geodynamics. M., 1994; World ocean atlas 2001: In 6 vol. Silver Spring, 2002.

P. N. Makkaveev; AF Limonov (geological structure).

The Atlantic Ocean is the second largest and the youngest ocean on Earth, distinguished by its unique relief and natural features.

The best resorts are located on its shores, and the richest resources are hidden in its depths.

Research history

Long before the onset of our era, the Atlantic was an important trade, economic and military route. The ocean was named after the ancient Greek mythological hero - Atlanta. The first mention is found in the writings of Herodotus.

The voyages of Christopher Columbus

Over the centuries, more and more straits and islands were opened, disputes over the sea territory and ownership of the islands were fought. But he still discovered the Atlantic, led the expedition and discovered most geographic objects.

Antarctica, and at the same time southern border sea waters were discovered by the Russian explorers F.F.Bellingshausen and M.P. Lazarev.

Characteristics of the Atlantic Ocean

The ocean area is 91.6 million km². It, like the Pacific Ocean, washes 5 continents. The volume of water in it is slightly more than a quarter of the world's oceans. It has an interesting elongated shape.

The average depth is 3332 m, the maximum depth is found in the Puerto Rico trench area and is 8742 m.

The maximum salinity of water reaches 39% (Mediterranean Sea), in some areas 37%. There are also the most fresh regions with an indicator of 18%.

Geographical position

The Atlantic Ocean in the north washes the shores of Greenland. From the west, it touches the eastern shores of North and South America. In the south, there are established borders with the Indian and Pacific Oceans.

The waters of the Atlantic and Indian oceans meet here

They are determined by the meridian of Cape Igolny and Cape Horn, respectively, reaching up to the glaciers of Antarctica. In the east, the waters wash over Eurasia and Africa.

Currents

The temperature of the water is strongly influenced by cold currents coming from the Arctic Ocean.

Warm currents are trade winds that affect waters near the equator. This is where it starts warm current The Gulf Stream, which passes through the Caribbean Sea basin, makes the climate of the coastal countries of Europe much warmer.

The cold Labrador Current runs along the coast of North America.

Climate and climatic zones

The Atlantic Ocean extends to all climatic zones. The temperature regime is strongly influenced by westerly winds, trade winds and monsoons in the equatorial region.

In the tropics and subtropics, the average temperature is 20 ° С, in winter it drops to 10 ° С. In the tropics, abundant rainfall prevails throughout the year, in the subtropics, they fall to a much greater extent in summer. Temperatures drop significantly in the Arctic and Antarctic regions.

Inhabitants of the Atlantic Ocean

From the flora in the Atlantic Ocean, kelp, corals, red and brown algae are widespread.

It is also home to more than 240 species of phytoplankton and an uncountable number of fish species, the most prominent representatives of which are: tuna, sardines, cod, anchovies, herring, perch (sea), halibut, haddock.

Of the mammals, several types of whales can be found there, the most common is the blue whale. The waters of the ocean are also inhabited by octopuses, crustaceans, squids.

The flora and fauna of the ocean is much poorer than that of the Pacific. This is due to the relatively small age and less favorable temperature conditions.

Islands and peninsulas

Some islands were formed as a result of the rise of the Mid-Atlantic Ridge above sea level, such as the Azores and the Tristan da Cunha archipelago.

Tristan da Cunha island

The most famous and mysterious are Bermuda.

Bermuda

On the territory of the Atlantic Ocean are located: Caribbean, Antilles, Iceland, Malta (state on the island), about. St. Helena - there are 78 of them. Favorite places for visiting tourists are the Canary Islands, the Bahamas, Sicily, Cyprus, Crete and Barbados.

Straits and seas

The waters of the Atlantic include 16 seas, among which the most famous and largest are: Mediterranean, Caribbean, Sargasso.

The Caribbean Sea meets the Atlantic Ocean

The Strait of Gibraltar connects the ocean current with the Mediterranean Sea.

The Strait of Magellan (runs along Tierra del Fuego and is distinguished by a large number of sharp rocks) and the Drake Strait go out into the Pacific Ocean.

Features of nature

The Atlantic Ocean is the youngest on Earth.

A significant part of the waters extends in the tropics and temperate zones, therefore animal world presented in all its diversity both among mammals and among fish and other sea creatures.

The diversity of plankton species is not great, but only here its biomass per 1 m³ can be so great.

Bottom relief

The main feature of the relief is the Mid-Atlantic Ridge, which is more than 18,000 km long. For a long distance from both sides of the ridge, the bottom is covered with hollows with a flat bottom.

There are also small underwater volcanoes, some of which are active. The bottom is cut by deep gorges, the origin of which is still not known exactly. However, due to age, relief formations prevailing in other oceans are developed here to a much lesser extent.

Coastline

In some parts the coastline is poorly indented, but the coast is quite rocky there. There are several large water areas, for example, the Gulf of Mexico, the Gulf of Guinea.

Gulf of Mexico

In the region of North America and the eastern coasts of Europe, there are many natural bays, straits, archipelagos and peninsulas.

Minerals

The Atlantic Ocean produces oil and gas, which accounts for a large share of the world's total mineral production.

Also on the shelves of some seas, sulfur, ore, precious stones and metals important to the global industry.

Ecological problems

In the 19th century, whale hunting was widespread in these places among sailors to get their fat and bristles. As a result, their number was sharply reduced to critical; now there is a ban on whaling.

Waters are highly polluted due to use and disposal:

huge quantities of oil in the bay in 2010;
production waste;
urban waste;
radioactive substances from stations, poisons.

This not only pollutes the water, degrades the biosphere and kills all life in the water, but equally affects the pollution of the environment in cities, the consumption of products containing all these substances.

Economic activities

In the Atlantic Ocean, 4/10 of the volume of fishing is carried out. It is through it that a huge number of shipping routes pass (the main of which are directed from Europe to North America).

The routes passing through the Atlantic Ocean and the seas located in it lead to the largest ports, which are of great importance in the import and export trade. Oil, ore, coal, wood, products and raw materials of the metallurgical industry, food products are transported through them.

On the shores of the Atlantic Ocean, there are many world tourist cities that attract a large number of people every year.

Interesting facts about the Atlantic Ocean

The most curious of them:

Conclusion

The Atlantic Ocean is the second largest, but by no means less significant. It is an important source of minerals, the fishing industry; the most important transport routes pass through it. Briefly summing up, it is worth paying attention to the enormous damage to the ecological and organic component of ocean life, caused by humanity.

Atlantic Ocean- the second largest ocean after the Pacific Ocean. It contains 25% of all the water on the planet. The average depth is 3,600 m. The maximum depth is in the Puerto Rico trench - 8,742 m. The ocean area is 91 million square meters. km.

general information

The ocean emerged as a result of the split of the supercontinent " Pangea"Into two large parts, which later formed into the modern continents.

The Atlantic Ocean has been known to man since ancient times. Mentioning about the ocean, which “ referred to as the Atlantic“, Can be found in the records of the 3rd century. BC. The name probably originated from the legendary missing mainland “ Atlantis«.

True, it is not clear what territory he designated, because in ancient times people were limited in means of transportation by sea.

Relief and islands

A distinctive feature of the Atlantic Ocean is a very small number of islands, as well as a complex bottom topography, which forms many pits and troughs. The deepest among them are the Puerto Rico and South Sandwich troughs, which are more than 8 km deep.

Earthquakes and volcanoes have a great impact on the structure of the bottom; the greatest activity of tectonic processes is observed in the equatorial zone.

Volcanic activity in the ocean has been going on for 90 million years. The height of many underwater volcanoes exceeds 5 km. The largest and most famous are found in the trenches of Puerto Rico and Yuno Sandwich, as well as on the Mid-Atlantic Ridge.

Climate

The long meridional length of the ocean from north to south explains the variety of climatic conditions on the ocean surface. In the equatorial zone, slight fluctuations in temperature throughout the year and an average of +27 degrees. The exchange of water with the Arctic Ocean also has a huge impact on the temperature of the ocean. Tens of thousands of icebergs drift from the north into the Atlantic Ocean, reaching almost to tropical waters.

The Gulf Stream, the largest current on the planet, is emerging off the southeastern coast of North America. Water consumption per day is 82 million cubic meters, which is 60 times higher than that of all rivers. The width of the current reaches 75 km. in width, and a depth of 700 m. The speed of the current ranges from 6-30 km / h. The Gulf Stream carries warm waters, the temperature of the upper layer of the current is 26 degrees.

In the area of about. Newfoundland The Gulf Stream meets the "cold wall" of the Labrador Current. The mixing of waters is created ideal conditions for the reproduction of microorganisms in the upper layers. Best known for this Large Newfoundland barrel, which is a source of fishing for fish such as cod, herring and salmon.

Flora and fauna

The Atlantic Ocean is characterized by an abundance of biomass with a relatively poor species composition in the northern and southern margins. The greatest species diversity is observed in the equatorial zone.

Of the fish, the most common are the families of nanotenium and white-blooded pikes. Large mammals are most widely represented: cetaceans, seals, fur seals, etc. The amount of plankton is insignificant, which leads to the migration of whales to feeding fields to the north or to temperate latitudes, where there is more of it.

Many places in the Atlantic Ocean have been and continue to be intense fishing grounds. Earlier exploration of the ocean led to the fact that hunting for mammals is already widespread here. long time... This has reduced the number of some animal species compared to the Pacific and Indian Oceans.

Plants presented a wide range green, brown and red algae. The famous Sargassos form the Sargasso Sea, which is popular in books and interesting stories.

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