The Atlantic Ocean is considered one of the largest and most voluminous in size, namely the second in size after the Pacific Ocean. This ocean is the most studied and developed when compared with other water areas. Its location is as follows: in the east it is framed by the shores of North and South America, and in the west its borders end in Europe and Africa. In the South it turns into South ocean. And on the northern side it borders with Greenland. The ocean is distinguished by the fact that there are very few islands in it, and the topography of its bottom is all dotted and has a complex structure. The coastline is broken.
Characteristics of the Atlantic Ocean
If we talk about the area of the ocean, it occupies 91.66 million square meters. km. We can say that part of its territory is not the ocean itself, but existing seas and bays. The volume of the ocean is 329.66 million square meters. km, and its average depth is 3736 m. Where the Puerto Rico Trench is located, the ocean is considered to have the greatest depth, which is 8742 m. There are two currents - Northern and Southern.
Atlantic Ocean from the north
The ocean boundary from the north is marked in some places by ridges located under water. In this hemisphere, the Atlantic is framed by an indented coastline. Its small northern part is connected to the Northern Arctic Ocean several narrow straits. Davis Strait is located in the northeast and connects the ocean with the Baffin Sea, which is also considered to belong to the Arctic Ocean. Closer to the center, the Denmark Strait is less wide than the Davis Strait. Between Norway and Iceland, closer to the northeast, is the Norwegian Sea.
In the South-West Northern Current oceans are Gulf of Mexico, which is connected by the Strait of Florida. And also the Caribbean Sea. There are many bays to note here, such as Barnegat, Delaware, Hudson Bay and others. It is in the northern side of the ocean that you can see the largest and largest islands, which are famous for their fame. These are Puerto Rico, the world famous Cuba and Haiti, as well as the British Isles and Newfoundland. Closer to the east you can find small groups of islands. These are the Canary Islands, the Azores and Cape Verde. Closer to the west are the Bahamas and the Lesser Antilles.
South Atlantic Ocean
Some geographers believe that the southern part is the entire space up to Antarctica. Someone defines the border at Cape Horn and Cape Good Hope two continents. Coast in the south Atlantic Ocean not as rugged as in the north, and there are no seas. There is one large bay near Africa - Guinea. The farthest point in the south is Tierra del Fuego, which is framed by small islands in large numbers. Also, you cannot find large islands here, but there are separate islands, like. Ascension, St. Helena, Tristan da Cunha. In the far south you can find the Southern Islands, Bouvet, Falkland and others.
As for the current in the southern ocean, here all systems flow counterclockwise. Near eastern Brazil, the South Trade Wind Current branches. One branch goes north, flows near the northern coast of South America, filling the Caribbean. And the second is considered southern, very warm, moves near Brazil and soon connects with the Antarctic Current, then heads to east side. Partially separates and turns into the Benguela Current, which is distinguished by its cold waters.
Attractions of the Atlantic Ocean
There is a special underwater cave in the Belize Barrier Reef. It was called the Blue Hole. It is very deep, and inside it there is a whole series of caves that are connected to each other by tunnels. The depth of the cave reaches 120 m and is considered unique of its kind.
There is no person who does not know about the Bermuda Triangle. But it is located in the Atlantic Ocean and excites the imagination of many superstitious travelers. Bermuda attracts with its mystery, but at the same time frightens with the unknown.
It is in the Atlantic that you can see an unusual sea that has no shores. And all because it is located in the middle of a body of water, and its boundaries cannot be framed by land, only currents show the boundaries of this sea. This is the only sea in the whole world that has such unique data and is called Sargasso Sea.
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ATLANTIC OCEAN(Latin name Mare Atlanticum, Greek 'Ατλαντίς - denoted the space between the Strait of Gibraltar and the Canary Islands, the entire ocean was called Oceanus Occidentalis - Western ca.), the second largest ocean on Earth (after the Pacific ca.), part Worldwide approx. Modern name first appeared in 1507 on the map of the Lorraine cartographer M. Waldseemüller.
Physiographical sketch
General information
In the north, the border of A. o. with the Arctic basin approx. passes along the east. entrance to Hudson Strait, then through Davis Strait. and along the coast of. Greenland to Cape Brewster, through 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 along 61° N. w. to the coast of the Scandinavian Peninsula. In the east of A. o. limited by the shores of Europe and Africa, in the west by the shores of the North. America and South America. Border of A. o. with Indian approx. draw along a line running from Cape Agulhas along the meridian 20° east. to the coast of Antarctica. Border with the Pacific approx. carried out from Cape Horn along the meridian 68°04′ W. or at the shortest distance from South. America to the Antarctic Peninsula through the Strait. Drake, from Fr. Oste to Cape Sterneck. South part of A. o. sometimes called the Atlantic sector of the Southern region, drawing the border along the subantarctic zone. convergence (approximately 40° S). Some works propose the division of A. o. to the North and Yuzh. The Atlantic Oceans, but it is more common to view it as a single ocean. A. o. – the most biologically productive of the oceans. It contains the longest underwater ocean. ridge – Mid-Atlantic Ridge; the only sea that does not have solid shores, limited by currents - Sargasso Sea; hall. Fundy with the highest tidal wave; to the A. o. pool applies Black Sea with a unique hydrogen sulfide layer.
A. o. stretches from north to south for almost 15 thousand km, its smallest width is approx. 2830 km in the equatorial part, the largest – 6700 km (along the parallel of 30° N). Area of A. o. with seas, bays and straits 91.66 million km 2, without them - 76.97 million km 2. The volume of water is 329.66 million km 3, without seas, bays and straits - 300.19 million km 3. Wed. depth 3597 m, greatest – 8742 m (trench Puerto Rico). The most easily accessible shelf zone of the ocean (with depths up to 200 m) occupies approx. At 5% of its area (or 8.6% if seas, bays and straits are taken into account), its area is larger than that of the Indian and Pacific Oceans, and significantly smaller than that of the Arctic Ocean. Areas with depths from 200 m to 3000 m (continental slope zone) occupy 16.3% of the ocean area, or 20.7% taking into account seas and bays, more than 70% is the ocean bed (abyssal zone). See map.
Seas
In the basin of A. o. - numerous seas, which are divided into: internal - Baltic, Azov, Black, Marmara and Mediterranean (the latter, in turn, includes the following seas: Adriatic, Alboran, Balearic, Ionian, Cyprus, Ligurian, Tyrrhenian, Aegean); interisland – Irish and int. western seas coast of Scotland; marginal - Labrador, Northern, Sargasso, Caribbean, Scotia (Scotia), Weddell, Lazareva, west. part of the Riiser-Larsen (see separate article on the seas). The largest bays of the ocean: Biscay, Bristol, Guinea, Mexico, Maine, St. Lawrence. The most important straits of the ocean: Great Belt, Bosporus, Gibraltar, Dardanelles, Danish, Davis, Drake, Oresund (Sound), Cabot, Kattegat, Kerch, English Channel (including Pas de Calais), Little Belt, Messina, Skagerrak , Florida, Yucatan.
Islands
Unlike other oceans, in A. o. There are few seamounts, guyots and coral reefs, and there are no coastal reefs. The total area of the islands of A. o. OK. 1070 thousand km 2. Basic 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, Tierra del Fuego archipelago (Terra del Fuego, Oste, Navarino) , Marajo, Sicily, Sardinia, Lesser Antilles, Falklands (Malvinas), Bahamas, etc. In the open ocean there are small islands: Azores, Sao Paulo, Ascension, Tristan da Cunha, Bouvet (on the Mid-Atlantic Ridge), etc. .
Shores
Coastline in the north. parts of A. o. heavily indented (see also Shore), almost all large inland seas and bays are located here, in the south. parts of A. o. The banks are slightly indented. The coasts of Greenland, Iceland and the coast of Norway are predominant. tectonic-glacial dissection of fjord and fiard types. Further south, in Belgium, they give way to sandy, shallow shores. Coast of Flanders ch. arr. arts origin (coastal dams, polders, canals, etc.). Shores of the island Great Britain and about. Ireland has abrasion bays, high limestone cliffs alternating with sandy beaches and muddy drainage areas. The Cotentin Peninsula has rocky shores, sandy and gravel beaches. North The coast of the Iberian Peninsula is composed of rocks; to the south, off the coast of Portugal, sandy beaches predominate, often enclosing lagoons. Sandy beaches also border the shores of the West. Sahara and Mauritania. To the south of Cape Zeleny there are leveled abrasion-bay shores with mangroves. Zap. The Ivory Coast site has an accumulative coastline with rocky headlands. To the southeast, to the vast river delta. Niger is an accumulative coast, which means. number of spits, lagoons. In the southwest Africa - accumulative, less often abrasion-bay shores with extensive sandy beaches. The coast of southern Africa is of abrasion-bay type and is composed of solid crystalline rocks. breeds Arctic shores Canada abrasive, with high cliffs, glacial deposits and limestones. To the east Canada and northern parts of the hall St. Lawrence contains intensively eroded cliffs of limestone and sandstone. In the west and south there is a hall. St. Lawrence – wide beaches. On the shores of the Canadian provinces of Nova Scotia, Quebec, and Newfoundland there are outcrops of solid crystalline particles. breeds From approximately 40° N. w. to Cape Canaveral in the USA (Florida) - alternation of leveled accumulative and abrasive types of shores composed of loose rocks. Coast of the Gulf of Mexico. low-lying, bordered by mangroves in Florida, sand barriers in Texas and deltaic shores in Louisiana. On the Yucatan Peninsula there are cemented beach sediments, to the west of the peninsula there is an alluvial-marine plain with coastal levees. On the coast of the Caribbean Sea, abrasion and accumulative areas alternate with mangrove swamps, coastal barriers and sandy beaches. South of 10° N. w. Accumulative banks are common, composed of material carried out from the mouth of the river. Amazon and other rivers. In the northeast of Brazil there is a sandy coast with mangroves, interrupted by river estuaries. From Cape Kalkanyar to 30° S. w. – a high, deep shore of abrasion type. To the south (off the coast of Uruguay) there is an abrasion-type coast composed of clays, loess and sand and gravel deposits. In Patagonia, the shores are represented by high (up to 200 m) cliffs with loose sediments. The coasts of Antarctica are 90% composed of ice and belong to the ice and thermal abrasion type.
Bottom relief
At the bottom of A. o. The following major geomorphological structures are distinguished: provinces: underwater continental margins (shelf and continental slope), ocean floor (deep-sea basins, abyssal plains, abyssal hill zones, uplifts, mountains, deep-sea trenches), mid-ocean. ridges.
Boundary of the continental shelf (shelf) of the A. region. 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 (northeast Brazil, Iberian Peninsula) to several hundred km (Northern Sea, Gulf of Mexico, Newfoundland Bank). In high latitudes, the shelf topography is complex and bears traces of glacial influence. Numerous uplifts (banks) are separated by longitudinal and transverse valleys or trenches. Off the coast of Antarctica there are ice shelves on the shelf. At low latitudes, the shelf surface is more leveled, especially in zones where rivers carry terrigenous material. It is crossed by transverse valleys, often turning into canyons of the continental slope.
The slope of the continental slope of the ocean is on average. 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 area of the Bahamas and the Puerto Rico Trench. Active margins are characterized by high seismicity. The surface of the slope is in some places dissected by steps, ledges and terraces of tectonic and accumulative origin and longitudinal canyons. At the foot of the continental slope there are often gentle hills high. up to 300 m and shallow underwater valleys.
In the middle part of the bottom of the A. lake. the largest mountain system Mid-Atlantic Ridge. It extends from Fr. Iceland to o. Bouvet at 18,000 km. The width of the ridge ranges from several hundred to 1000 km. The crest of the ridge runs close to the midline of the ocean, dividing it to the east. and zap. parts. On both sides of the ridge there are deep-sea basins, separated by bottom rises. In zap. parts of A. o. From north to south there are basins: 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) with the Pernambuco abyssal plain; Argentinean (5000–6000 m). To the east parts of A. o. 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 (approx. 5000 m), Guinean (over 6000 m). 5000 m), Angola (up to 6000 m), Cape (over 5000 m) with abyssal plains of the same name. In the south is the African-Antarctic Basin with the Weddell Abyssal Plain. The bottoms of deep-sea basins at the foot of the Mid-Atlantic Ridge are occupied by a zone of abyssal hills. The basins are separated by the Bermuda, Rio Grande, Rockall, Sierra Leone, etc. uplifts, and the Whale, Newfoundland, and other ridges.
Seamounts (isolated conical heights of 1000 m or more) at the bottom of the Arctic Ocean. concentrated primarily in the Mid-Atlantic Ridge area. In the deep sea large groups seamounts are found north of the Bermuda Islands, in the Gibraltar sector, off the north-east. ledge South America, in the Guinea Hall. and west of South. Africa.
Deep sea trenches of Puerto Rico, Caiman(7090 m), South Sandwich Trench(8264 m) are located near island arcs. Gutter Romanche(7856 m) represents major fault. The steepness of the slopes of deep-sea trenches is from 11° to 20°. The bottom of the gutters is flat, leveled by accumulation processes.
Geological structure
A. o. arose as a result of the breakup of the Late Paleozoic supercontinent Pangea in Jurassic time. It is characterized by a sharp predominance of passive outskirts. A. o. borders on adjacent continents transform faults south of the island Newfoundland, along the north. coast of the Gulf of Guinea, along the Falkland submarine plateau and the Agulhas plateau in the south. parts of the ocean. Active margins are observed in the section. areas (in the area of the Lesser Antilles arc and the arc of the South Sandwich Islands), where subsidence occurs ( subduction) lithosphere of the A. o. The Gibraltar subduction zone, limited in extent, was identified in the Gulf of Cadiz.
In the Mid-Atlantic Ridge, the seafloor is moving apart ( spreading) and the formation of oceanic. bark at a rate of up to 2 cm per year. Characterized by high seismicity. and volcanic activity. In the north, paleospreading ridges branch off from the Mid-Atlantic Ridge into the Cape of Labrador and into the Bay of Biscay. In the axial part of the ridge there is a clearly defined rift valley, which is absent in the extreme south and in the bay. part of the Reykjanes ridge. Within its borders there is a volcanic. uplifts, frozen lava lakes, basaltic lava flows in the form of pipes (pillow basalts). To the Center Metalliferous fields discovered in the Atlantic 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 valley slopes there are screes and landslides consisting of blocks and crushed stone of oceanic rocks. crust (basalts, gabbros, peridotites). The age of the crust within the Oligocene ridge is modern. The Mid-Atlantic Ridge divides the western zones. and east abyssal plains, where oceanic. the foundation is covered by a sedimentary cover, the thickness of which increases in the direction of the continental foothills to 10–13 km due to the appearance of more ancient horizons in the section and the supply of clastic material from land. In the same direction, the age of oceanic animals increases. 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 concentration of such faults is observed in the equatorial zone (up to 12 per 1700 km). The largest transform faults (Vima, Sao Paulo, Romanche, etc.) are accompanied by deep incisions (trenches) on the ocean floor. They reveal the entire oceanic section. crust and partly upper mantle; Protrusions (cold intrusions) of serpentinized peridotites are widely developed, forming ridges elongated along the strike of the faults. Mn. transform faults are transoceanic, or main (demarcation) faults. In A. o. there are so-called intraplate uplifts, represented by underwater plateaus, aseismic ridges and islands. They have oceanic bark of increased thickness and have ch. 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. K volcanic uplifts include: o. Iceland, o. Bouvet, oh. Madeira, the Canary Islands, Cape Verde, the 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, etc. There are intraplate uplifts of non-volcanic ones. nature, which includes the underwater Rockall Plateau, separated from the British Islands by one. touching. The plateau represents microcontinent, separated from Greenland in the Paleocene. Another microcontinent that also separated from Greenland is the Hebrides in northern Scotland. The underwater marginal plateaus off the coast of Newfoundland (Great Newfoundland, Flemish Cap) and off the coast of Portugal (Iberian) were separated from the continents as a result of rifting at the end of the Jurassic - the beginning of the Cretaceous.
A. o. is divided by transoceanic transform faults into segments with different time disclosures. 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 (ca. 200 million years ago) from the Central segment. In the Triassic - Early Jurassic, oceanic spreading occurred. the bottom was preceded by continental rifting, traces of which are recorded in the form of half-grabens filled with clastic deposits in the Amer. and northern - African the edges of the ocean. At the end of the Jurassic - the beginning of the Cretaceous, the Antarctic segment began to open. In the Early Cretaceous, spreading was experienced by the South. segment in South Atlantic and the Newfoundland-Iberian segment in the North. Atlantic. The opening of the Labrador-British segment began at the end of the Early Cretaceous. At the end of the Late Cretaceous, the Labrador Sea basin arose here as a result of spreading on a side axis, which continued until the late Eocene. North and Yuzh. The Atlantic merged in the mid-Cretaceous - Eocene during the formation of the Equatorial segment.
Bottom sediments
Thickness of the modern strata. bottom sediments range from a few m in the crest zone of the Mid-Atlantic Ridge to 5–10 km in transverse fault zones (for example, in the Romanche Trench) and at the foot of the continental slope. In deep-sea basins, their thickness ranges from several tens to 1000 m. More than 67% of the area of the ocean floor (from Iceland in the north to 57–58° S) is covered with calcareous deposits formed by the remains of shells of planktonic organisms (mostly foraminifera, coccolithophoride). Their composition varies from coarse sands (at depths up to 200 m) to silts. At depths of more than 4500–4700 m, calcareous silts are replaced by polygenic and siliceous planktogenic sediments. The first ones take approx. 28.5% of the ocean floor area, lining the bottoms of basins, and are represented red deep ocean clay(deep-sea clayey silts). These sediments contain means. amounts of manganese (0.2–5%) and iron (5–10%) and very small amounts 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 diatomaceous oozes (formed by the skeletons of diatoms). They are common off the coast of Antarctica and on the southwest shelf. Africa. Radiolarian oozes (formed by the skeletons of radiolarians) are found Ch. arr. in the Angola Basin. Along the ocean coasts, on the shelf and partly on the continental slopes, terrigenous sediments of various compositions (gravel-pebble, sandy, clayey, etc.) are developed. The composition and thickness of terrigenous sediments are determined by the bottom topography and the activity of influx hard material from land and the mechanism of their transfer. Glacial sediments carried by icebergs are common along the coast of Antarctica. Greenland, o. Newfoundland, Labrador Peninsula; composed of poorly sorted clastic material with the inclusion of boulders, mostly in the south of the Autonomous Region. 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 Sea and the north-east. coast of Brazil; their maximum depth is 3500 m. Volcanogenic sediments are developed near volcanics. islands (Iceland, Azores, Canaries, Cape Verde, etc.) and are represented by volcanic fragments. rocks, slag, pumice, volcanic. ashes. Modern chemogenic sediments are found on the Great Bahama Bank, in the Florida-Bahamas, Antilles regions (chemogenic and chemogenic-biogenic carbonates). In the basins of North America, Brazil, and Cape Verde there are ferromanganese nodules; their composition in A. o.: 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 near the east. coast of the USA and north-west. coast of Africa. Phosphorites are common along the east. coast of A. o. – from the Iberian Peninsula to Cape Agulhas.
Climate
Due to the large extent of A. o. its waters are located in almost all natural climates. zones - from subarctic in the north to Antarctic in the south. From the north and south, the ocean is wide open to the influence of the Arctic. and Antarctic waters and ices. The lowest air temperatures are observed in the polar regions. Over the coast of Greenland, temperatures can drop to –50 °C, and in the south. In parts of Cape Weddell, 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 consistent change of stable large pressure formations. There are anticyclones over the ice domes of Greenland and Antarctica, 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 pressure structure maintains tropical temperatures. and equatorial latitudes, stable winds are east. directions (trade winds), in temperate latitudes – strong winds zap. directions that were named by sailors. "Roaring Forties". Strong winds are also typical for the Bay of Biscay. In the equatorial region, the interaction of northern. and south pressure systems lead to frequent tropical cyclones (tropical hurricanes), the greatest activity of which is observed from July to November. Horizontal dimensions 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 greatest strength over the Caribbean Sea and the Mexican Hall. Low pressure areas in temperate and equatorial latitudes often experience precipitation and heavy cloud cover. So, St. falls on the equator. 2000 mm of precipitation per year, in temperate latitudes - 1000–1500 mm. In areas of high pressure (subtropics and tropics), precipitation decreases to 500–250 mm per year, and in areas adjacent to the desert coasts of Africa and in the South Atlantic High, to 100 mm or less per year. In areas where warm and cold currents meet, fogs are frequent, for example. in the Newfoundland Bank area and into the hall. La Plata.
Hydrological regime
Rivers and water balance With. To the pool of A. o. Every year 19,860 km 3 of water is carried out by rivers, this is more than into any other ocean (about 45% of the total flow into the World Ocean). The largest rivers (with an annual flow of over 200 km 3): Amazon, Mississippi(flows into the Gulf of Mexico.), 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 of the A. o. negative: evaporation from its surface (100–125 thousand km 3 / year) significantly exceeds atmospheric precipitation (74–93 thousand km 3 / year), river and underground runoff (21 thousand km 3 / year) and melting of ice and icebergs in the Arctic and Antarctic (approx. 3 thousand km 3 /year). The water balance deficit is compensated by the influx of water, ch. arr. from the Pacific Ocean, through the Drake Passage with the current of the Western Winds, 3,470 thousand km 3 /year comes, and from the A. o. in Quiet approx. only 210 thousand km 3 /year goes away. From the Arctic Ocean approx. through numerous straits in A. o. 260 thousand km 3 /year and 225 thousand km 3 /year are received from the Atlantic. water flows back to the Arctic approx. Water balance with Indian ca. negative, in Indian approx. with the flow of the Western Winds, 4976 thousand km 3 /year are carried out, and return with the Coastal Antarctic Sea. current, deep and bottom waters only 1692 thousand km 3 /year.
Temperature regime m. Wed. the temperature of the ocean waters as a whole is 4.04 °C, and surface waters 15.45 °C. The distribution of water temperature on the surface is asymmetrical relative to the equator. Strong influence of the Antarctic. water leads to the fact that the surface waters of the South. hemisphere is almost 6 °C colder than the Northern hemisphere, the warmest waters of the open part of the ocean (thermal equator) are between 5 and 10 ° N. sh., i.e. shifted to the north of the geographic. equator. Features of large-scale water circulation lead to the fact that the water temperature on the surface near the west. The ocean shores are approximately 5 °C higher than those on the eastern shores. The warmest water temperature (28–29 °C) on the surface is in the Caribbean Sea and Gulf of Mexico. in August, the lowest is off the coast of the island. Greenland, o. Baffin Island, Labrador and Antarctica peninsulas, south of 60°, where even in summer the water temperature does not rise above 0 °C. Temperature of water in the layer Ch. thermocline (600–900 m) is approx. 8–9 °C, deeper, in intermediate waters, falls on Wed. up to 5.5 °C (1.5–2 °C in Antarctic intermediate waters). In deep waters, water temperature on avg. 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. In the waters of A. o. contains approx. 1.1×10 16 t salts. Wed. The salinity of the waters of the entire ocean is 34.6‰, and the salinity of surface waters is 35.3‰. The highest salinity (over 37.5‰) is observed on the surface in the subtropics. areas where the evaporation of water from the surface exceeds its supply with precipitation, the lowest (6–20‰) in the mouth areas of large rivers flowing into the ocean. From the subtropics to high latitudes, surface salinity decreases to 32–33‰ under the influence of precipitation, ice, river and surface runoff. In temperate and tropical areas max. salinity values are on the surface; an intermediate minimum of salinity is observed at depths of 600–800 m. Northern waters. parts of A. o. 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 water density field. Waters with the lowest density are located in the equatorial and tropical regions. areas with high water temperatures and strong influence of runoff from rivers such as the Amazon, Niger, Congo, etc. (1021.0–1022.5 kg/m3). To the south In the northern part of the ocean, the density of surface water increases to 1025.0–1027.7 kg/m 3 , in the northern part – to 1027.0–1027.8 kg/m 3 . Density of deep waters of the A. o. 1027.8–1027.9 kg/m3.
Ice regime in the north. parts of A. o. First-year ice is formed ch. arr. in internal seas of temperate latitudes, multi-year ice is carried out of the Arctic approx. The limit of the distribution of ice cover in the north. parts of A. o. changes significantly in winter period pack ice can reach decomposition. years 50–55° N. w. There is no ice in summer. Antarctic border Multi-year ice in winter passes at a distance of 1600–1800 km from the coast (approximately 55° S); in summer (February–March) ice is found only in the coastal strip of Antarctica and in Weddell Cape. Basic Suppliers of icebergs are the ice sheets and ice shelves of Greenland and Antarctica. The total mass of icebergs coming from the Antarctic. glaciers, estimated at 1.6×10 12 tons per year, base. their source is the Filchner Ice Shelf in Weddell Cape. From the glaciers of the Arctic to the Arctic. icebergs with a total mass of 0.2–0.3 × 10 12 tons per year are received, mainly from the Jakobshavn glacier (in the area of Disko Island off the western coast of Greenland). Wed. life expectancy of the arctic icebergs approx. 4 years, slightly more Antarctic. The limit of iceberg distribution in the north. part of the ocean 40° N. sh., but in dep. in cases they were observed up to 31° N. w. To the south parts of the border passes at 40° south. sh., to the center. part of the ocean and at 35° south. w. to the west and east periphery.
Currents I. Water circulation of the A. o. is divided into 8 quasi-stationary oceanic. gyres located almost symmetrically relative to the equator. From low to high latitudes in the 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 originates near the Florida Peninsula Gulf Stream. Absorbing warm waters Antillean Current And Florida Current, The Gulf Stream heads northeast and at high latitudes splits into several branches; the most significant of them are Irminger Current, which transports warm waters to Davis Strait, the North Atlantic Current, Norwegian Current, going to the Norwegian Cape and further to the northeast, along the coast of the Scandinavian Peninsula. To meet them from Davis Strait. it comes out cold Labrador Current, the waters of which can be traced off the coast of America to almost 30° N. w. From the Danish Strait. The cold East Greenland Current flows into the ocean. At low latitudes, A. o. warm air flows from east to west Northern trade wind currents And Southern trade wind currents, between them, approximately 10° N. sh., from west to east there is an Intertrade Countercurrent, which is active Ch. arr. in summer in the North. hemispheres. Separates from the Southern Trade Wind Currents Brazilian Current, which runs from the equator to 40° S. w. along the coast of America. North the branch of the Southern Trade Wind Currents forms Guiana Current, which is directed from south to northwest until it connects with the waters of the Northern Trade Wind Currents. Off the coast of Africa from 20° N. w. The warm Guinea Current passes to the equator, in summer time The Intertrade Countercurrent is connected to it. To the south parts of A. o. crosses the cold Western Winds current(Antarctic Circumpolar Current), which is part of the Arctic Ocean. through the strait Drake, descends to 40° S. w. and goes out to Indian approx. south of Africa. Separated from it is the Falkland Current, which reaches along the coast of America almost to the mouth of the river. Parana, Benguela Current, running along the coast of Africa almost to the equator. Cold Canary Current passes from north to south - from the shores of the Iberian Peninsula to the Cape Verde Islands, where it turns into the Northern Trade Wind Currents.
Deep circulation in e. Deep circulation and structure of waters of the A.O. are formed as a result of changes in their density during cooling of waters or in zones of mixing of decomposed waters. origin, where density increases as a result of mixing water with decomposition. 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 the subpolar regions and are located at depths from 400–500 m to 1000–1500 m, with a temperature of 3 to 7 °C and a salinity of 34.0–34.9‰. The circulation of subsurface and intermediate waters is generally anticyclonic. character. Deep waters are formed in high northern latitudes. and south parts of the ocean. Waters formed in the Antarctic. area, have highest density and spread from south to north in the bottom layer, their temperature varies from negative (in high southern latitudes) to 2.5 °C, salinity 34.64–34.89‰. Waters formed in the high north. latitudes, move from north to south in a layer from 1500 to 3500 m, the temperature of these waters is from 2.5 to 3 °C, salinity is 34.71–34.99‰. In the 1970s V.N. Stepanov and, later, V.S. Broker substantiated the scheme of planetary interoceanic transfer of energy and matter, which was called. “global conveyor belt” or “global thermohaline circulation of the World Ocean”. According to this theory, the relatively salty North Atlantic. waters reach the coast of Antarctica, mix with supercooled shelf water and, passing through the Indian Ocean, end their journey to the north. parts of the Pacific Ocean.
Tides and waves e. Tides in A. o. preim. semi-daily allowance. Tidal wave height: 0.2–0.6 m in the open part of the ocean, a few cm in the Black Sea, 18 m in the bay. Fundy (the northern part of the Gulf of Maine in North America) is the highest in the world. The height of wind waves depends on the speed, time of exposure and acceleration of the wind; during strong storms it can reach 17–18 m. Quite rarely (once every 15–20 years) high waves have been observed. 22–26 m.
Flora and fauna
The large extent of the Arctic region, the diversity of climates. conditions, that is. influx of fresh water and large upwellings provide a variety of living conditions. In total, the ocean is inhabited by 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 distributed very unevenly in the ocean. There are three main ones. type of zonation of life distribution in the ocean: latitudinal, or climatic, vertical and circumcontinental. The density of life and its species diversity decrease with distance from the coast towards the open ocean and from the surface to deep waters. Species diversity also decreases from the tropics. latitude to high.
Planktonic organisms (phytoplankton and zooplankton) are the basis of the food chain in the ocean, mainly. a lot of them live in the upper zone of the ocean, where light penetrates. The highest biomass of plankton is in high and temperate latitudes during spring-summer flowering (1–4 g/m3). During the year, biomass can change 10–100 times. Basic species of phytoplankton - diatoms, zooplankton - copepods and euphausids (up to 90%), as well as chaetognaths, hydromedusas, ctenophores (in the north) and salps (in the south). At low latitudes, 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 Gulf of Mexico and Guinea. Phytoplankton is represented by Ch. arr. coccolithines and peridineans, the latter can develop in huge quantities in coastal waters, causing catastrophes. "red tide" phenomenon. Zooplankton at low latitudes is represented by copepods, chaetognaths, hyperids, hydromedusae, siphonophores and other species. There are no clearly defined dominant species of zooplankton at low latitudes.
The benthos is represented by large algae (macrophytes), which b. h. grow on the bottom of the shelf zone to a depth of 100 m and cover approx. 2% of the total ocean floor area. The development of phytobenthos is observed in places where there are suitable conditions - soils suitable for attachment to the bottom, the absence or moderate speeds of bottom currents, etc. In high latitudes, the A. o. basic part of the phytobenthos consists of kelp and red algae. IN temperate zone north parts of the A.O., along the American and European coasts, - brown algae(fucus and ascophyllum), kelp, desmarestia and red algae (furcellaria, ahnfeltia, etc.). Zostera is common on soft soils. In the temperate and cold zones of the south. parts of A. o. Brown algae predominate. In the tropics 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 Cape, where floating macrophytes (mainly three species of algae of the genus Sargassum) form clusters on the surface in the form of ribbons from 100 m to several m long. kilometers.
Most of the nekton biomass (actively swimming animals - fish, cephalopods and mammals) consists of fish. Largest number species (75%) live in the shelf zone, with depth and distance from the coast the number of species decreases. Characteristic for cold and temperate zones: from fish – decomposition. species of cod, haddock, pollock, herring, flounder, catfish, conger eel, etc., herring and arctic sharks; among mammals – pinnipeds (harp seal, hooded seal, etc.), decomp. species of cetaceans (whales, sperm whales, killer whales, pilot whales, bottlenose whales, etc.).
There is great similarity between the faunas of temperate and high latitudes of both hemispheres. At least 100 species of animals are bipolar, that is, they are characteristic of both temperate and high zones. For tropical zones of A. o. characteristic: from fish – decomposition. sharks, flying fish, sailboats, etc. species of tuna and glowing anchovies; among animals - sea turtles, sperm whales, river dolphin; Cephalopods are also numerous - various. species of squid, octopus, etc.
Deep-sea fauna (zoobenthos) A. o. represented by sponges, corals, echinoderms, crustaceans, mollusks, etc. worms.
History of the study
There are three stages of research into A. o. The first is characterized by the establishment of the boundaries of the ocean and the discoveries of its individual objects. AT 12- 5th centuries BC e. the Phoenicians, Carthaginians, Greeks and Romans left descriptions of sea travels and the first nautical charts. Their voyages reached the Iberian Peninsula, England and the mouth of the Elbe. In the 4th century. BC e.Piteas(Pytheas) while sailing to the North. Atlantic determined the coordinates of a number of points and described tidal phenomena in the Arctic Ocean. By the 1st century. n. e. There are references to the Canary Islands. In the 9th–10th centuries. Normans (RowdyEirik and his son Leif Eirikson) crossed the ocean, visited Iceland, Greenland, Newfoundland and explored the shores of the North. America under 40° s. w. In the eraGreat geographical discoveries(mid 15th – mid 17th centuries) seafarers (mostly Portuguese and Spanish) explored the route to India and China along the coast of Africa. The most outstanding voyages during this period were carried out by the Portuguese B.Diashem(1487), by the Genoese H.Columbus(1492–1503), 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 surface currents. First bathymetric map (depth map) of A. o. was compiled in Spain in 1523. In 1520 F.Magellanfirst passed from A. o. in Quiet approx. the strait later named after him. In the 16th–17th centuries. The Atlantic is being intensively studied. North coast America (English J.Davis, 1576–78, G. Hudson, 1610, U. Baffin, 1616, and other navigators whose names can be found on the ocean map). The Falkland Islands were discovered in 1591–92. South shores of A. o. - the continent of Antarctica - were discovered and first described by Russian. Antarctic expedition F.F.Bellingshausen and M.P. Lazarevin 1819–21. This completed the study of the ocean's boundaries.
The second stage is characterized by the study of physics. properties of ocean waters, temperature, salinity, currents, etc. In 1749, the Englishman G. Ellis made the first measurements of temperature at various depths, repeated by the Englishman J. Cook(1772), Swiss O. Saussure(1780), Russian I.F. Krusenstern(1803), etc. In the 19th century. A. o. becomes a testing ground for testing new methods for exploring depths, new equipment and new approaches to organizing work. For the first time, bathometers, deep-sea thermometers, thermal depth gauges, deep-sea trawls and dredges were used. Of the most significant expeditions, Russian can be noted. sailing on the ships "Rurik" (1815–18) and "Enterprise" (1823–26) under the leadership of O.E.Kotzebue(1815–18); English on "Erebus" and "Terror" under the direction of J.K.Rossa(1840–43); Amer. on the "Arctic" under the leadership of M.F.Mori(1856). Real comprehensive oceanographic Ocean exploration began with an expedition to English. corvette« Challenger" led by W. Thomson (1872–76). The significant expeditions that followed were carried out on the ships Gazelle (1874–76), Vityaz (1886–89), Valdivia (1898–99), and Gauss (1901–03). From 1885 to 1922, he made a great contribution to the study of A. o. contributed by Prince Albert I of Monaco, who organized and led expeditionary research on the yachts “Irendel”, “Princess Alice”, “Irendel II”, “Princess Alice II” in the north. parts of the ocean. During these same years, he organized the Oceanographic Museum in Monaco. Since 1903, work began on “standard” sections in the North Atlantic under the leadership of the International Council for the Exploration of the Sea (ICES), the first international oceanographic study. 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, and Atlantis. In 1931, the International Council of Scientific Unions (ICSU) was formed, which is still active today, organizing and coordinating ocean research.
After World War II, echo sounders began to be widely used to study the ocean floor. This allowed us to get real picture relief of the ocean floor. In the 1950s–70s. complex geophysical surveys were carried out. and geological research of A. o. and the features of the topography of its bottom, tectonics, and the structure of the sedimentary strata were established. Many large forms of bottom relief have been identified (underwater ridges, mountains, trenches, fault zones, extensive basins and uplifts), and geomorphological data have been compiled. and tectonic cards. Unique results were obtained from the international deep ocean drilling program IODP (1961–2015, ongoing).
The third stage of ocean research is aimed mainly at studying its role in global processes of matter and energy transfer and its influence on climate formation. The complexity and wide range of research work required a wide range of international cooperation. In the coordination and organization of international research big role They are played by the Scientific Committee for Ocean Research (SCOR), formed in 1957, the Intergovernmental Oceanographic Commission of UNESCO (IOC), operating since 1960, and other international organizations. In 1957–58, extensive work was carried out within the framework of the first International Geophysical Year (IGY). Subsequently, large international projects were aimed at studying individual parts of the A.O., for example, EQUALANT I–III (1963–64), Polygon-70 (1970), SIKAR (1970–75), POLYMODE (1977–78 ), and A. o. as parts of the World Ocean, for example TOGA (1985–89), GEOSECS (1973–74), WOCE (1990–96), etc. During these projects, the features of water circulation of various scales, distribution and composition of suspended matter were studied; the role of the ocean in the global carbon cycle and many others. other questions. In con. 1980s owls deep-sea vehicles"World» The unique ecosystems of geothermal regions of the ocean rift zone were studied. If at the beginning 80s it was ok. 20 international projects ocean exploration, then by the 21st century. St. 100. The largest programs:« International Geosphere-Biosphere Program» (since 1986, 77 countries participate), it includes projects« Dynamics of global ocean ecosystems» (GLOBES, 1995–2010), "Global flows of matter in the ocean» (JGOFS, 1988–2003), " Land–ocean interaction in the coastal zone» (LOICZ), Integrated Marine Biogeochemistry and Ecosystem Research (IMBER), Land-Ocean Interactions in coastal zone(LOICZ, 1993–2015), Study of the interaction of the ocean surface with the lower atmosphere (SOLAS, 2004–15, ongoing),« World Climate Research Program» (WCRP, since 1980, 50 countries involved), International study of biogeochemical cycles and large-scale distribution of trace elements and their isotopes in marine environment(GEOTRACES, 2006–15, ongoing) and many more. etc. Developing global system Ocean Observations (GOOS). One of the main projects of the WCRP was the Climate and Ocean: Volatility, Predictability and Variability program (CLIVAR, since 1995), which was based on the results of TOGA and WOCE. Ross. For many years, scientists have been conducting expeditionary studies of exchange processes at the border of the Arctic Ocean. and the Arctic Ocean, circulation in the Drake Passage, distribution of cold Antarctic waters along deep-sea faults. Since 2005, the international ARGO program has been operating, in which observations are carried out by autonomous sounding instruments throughout the World Ocean (including the Arctic Ocean), and the results are transmitted through artificial Earth satellites to data centers.
In November 2015, Russia sailed from Kronstadt to the shores of Antarctica for the first time in the last 30 years. research vessel of the Baltic Fleet "Admiral Vladimirsky". It made a journey over 34 thousand nautical miles. miles. Along the route, hydrographic, hydrological, hydrometeorological and radio navigation studies were carried out, information was collected to correct marine navigation charts, manuals and navigation manuals. Having rounded the southern tip of the African continent, the ship entered marginal seas Antarctica. He moored near the tower. Progress station, scientists exchanged data with station staff on monitoring ice conditions, melting Arctic ice, and weather. The expedition ended on April 15, 2016. In addition to the crew, hydrograph specialists from the 6th Atlantic Oceanographic Division took part in the expedition. hydrographic expeditions services of the Baltic Fleet, employees of the Russian Federation. state hydrometeorological University, the Institute of the Arctic and Antarctic, etc. Work has been completed 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. o. occupies the most important place in the global economy among other oceans of our planet. Human use of the Arctic Ocean, like other seas and oceans, is based on several principles. directions: transport and communications, fishing, mineral extraction. resources, energy, recreation.
Transport
Already for 5 centuries A. o. takes a leading role in maritime transport. With the opening of the Suez (1869) and Panama (1914) canals, short sea routes appeared between the Atlantic, Indian and Pacific Oceans. To the share of A. o. account for approx. 3/5 of the cargo turnover of world shipping, in con. 20th century up to 3.5 billion tons of cargo were transported across its waters per year (according to IOC data). OK. 1/2 of the transport volume is oil, gas and petroleum products, followed by general cargo, then iron ore, grain, coal, bauxite and alumina. Ch. The direction of transportation is North Atlantic, which runs between 35–40° N. w. and 55–60° N. w. Basic shipping routes connect port cities in Europe, the USA (New York, Philadelphia) and Canada (Montreal). This direction is adjacent to the Norwegian, Northern and inland sea routes. seas of Europe (Baltic, Mediterranean and Black). Transported to main raw materials (coal, ores, cotton, timber, etc.) and general cargo. Dr. important transportation directions - South Atlantic: Europe - Central (Panama, etc.) and South America (Rio de Janeiro, Buenos Aires); East Atlantic: Europe - southern Africa (Cape Town); Western-Atlantic: North. America, South America - South Africa. Before the reconstruction of the Suez Canal (1981) b. including oil tankers from the Indian basin approx. was forced to go around Africa.
Passenger transportation occupies an important place in the airport. since the 19th century, when mass emigration from the Old World to America began. The first steam-sailing ship, the Savannah, crossed the A.O. for 29 days in 1819. At the beginning. 19th century A Blue Ribbon prize has been established for passenger ships that can cross the ocean the fastest. This prize was awarded, for example, to such famous liners as the Lusitania (4 days and 11 hours), the Normandy (4 days and 3 hours), and the Queen Mary (4 days and 3 minutes). The last time the Blue Ribbon was awarded to Amer. to the United States liner in 1952 (3 days and 10 hours). In the beginning. 21st century flight duration passenger airliner between London and New York 5–6 days. Max. passenger transportation through A. o. occurred in 1956–57, when more than 1 million people were transported per year; in 1958, the volume of passenger transportation by air was equal to sea transportation, and then everything went on. h. passengers give preference air transport(record flight time of the supersonic Concorde airliner on the route New York - London - 2 hours 54 minutes). The first non-stop flight through A. O. committed 14–15.6.1919 English. pilots J. Alcock and A. W. Brown (Newfoundland Island - Ireland Island), the first non-stop flight through A.O. alone (from continent to continent) 5/20–21/1927 – Amer. pilot C. Lindberg (New York - Paris). In the beginning. 21st century almost the entire flow of passengers through the airport. served by aviation.
Connection
In 1858, when there was no radio communication between the continents, through the A. o. The first telegraph cable was laid. K con. 19th century 14 telegraph cables connected Europe with America and 1 with Cuba. In 1956, the first telephone cable was laid between the continents; by the mid-1990s. St. acted at the bottom of the ocean. 10 telephone lines. In 1988, the first transatlantic fiber-optic communication line was laid, at the beginning of the 21st century. 8 lines operate.
Fishing
A. o. considered the most productive ocean, his biological resources are most intensively exploited by humans. In A. o. Fishing and seafood production account for 40–45% of the total world catch (approx. 25% of the world). Most of the catch (up to 70%) consists of herring fish (herring, sardines, etc.), cod fish (cod, haddock, hake, whiting, pollock, navaga, etc.), flounder, halibut, and sea bass. Extraction of mollusks (oysters, mussels, squid, etc.) and crustaceans (lobsters, crabs) approx. 8%. According to FAO estimates, the annual catch of fish products in the A. region. is 85–90 million tons, but for most fishing areas of the Atlantic, fish catch reached mid. 1990s its maximum and increasing it is undesirable. The traditional and most productive fishing area is north-east. part of the Arctic Ocean, including the North and Baltic seas (mainly herring, cod, flounder, sprats, mackerel). In the north-west area of the ocean, on the Newfoundland banks, cod, herring, flounder, squid, etc. have been caught for many centuries. To the center. parts of A. o. There is a catch of sardines, horse mackerel, mackerel, tuna, etc. In the south, on the Patagonian-Falkland shelf, which is elongated in latitude, there is fishing for both warm-water species (tuna, marlin, swordfish, sardines, etc.) and cold-water species (blue whiting, hake , notothenia, toothfish, etc.). Off the coast of the west. and southwest African catch of sardine, anchovy and hake. In the Antarctic region In the ocean area, planktonic crustaceans (krill), marine mammals, and fish - notothenia, toothfish, silverfish, etc. are of commercial importance. Until mid. 20th century in high latitude northern and south areas of the ocean, active fishing was carried out. species of pinnipeds and cetaceans, but in recent decades it has sharply declined due to biological depletion. resources and thanks to environmental measures, including intergovernmental ones. agreements to limit their production.
Mineral resources
The development of the mineral is becoming more and more active. riches of the ocean floor. Oil and combustible gas deposits have been studied more fully, the first mentions of their exploitation in the Arctic basin. date back to 1917, when industrial oil production began. scale in the east. parts of the Maracaibo lagoon (Venezuela). The largest centers of marine production: Venezuelan Gulf, Maracaibo Lagoon ( Maracaiba oil and gas basin), Mexican Hall. ( Gulf of Mexico oil and gas basin), hall. Pariah ( Orinoco oil and gas basin), Brazilian shelf (Sergipe-Alagoas oil and gas basin), Gulf of Guinea. ( Gulf of Guinea oil and gas basin), Northern metro station ( North Sea oil and gas bearing area) etc. Placer deposits of heavy minerals are common along many coasts. The largest developments of placer deposits of ilmenite, monocyte, zircon, and rutile are carried out off the coast of Florida. Similar deposits are located in the Gulf of Mexico, near the east. coast of the USA, as well as Brazil, Uruguay, Argentina and the Falkland Islands. On the shelf southwest. In Africa, coastal sea diamond deposits are being developed. Gold placers were discovered off the coast of Nova Scotia at depths of 25–45 m. In A. o. One of the world's largest iron ore deposits, Wabana (in Conception Bay off the coast of Newfoundland), has been explored; iron ore is also mined off the coast of Finland, Norway and France. Coal deposits are being developed in the coastal waters of Great Britain and Canada, extracting it in mines located on land, the horizontal workings of which go under the seabed. On the shelf of the Gulf of Mexico. are being developed large deposits sulfur Gulf of Mexico sulfur province. In the coastal zone of the ocean, sand and gravel are mined for construction and glass production. On the shelf east. coast of the USA and western On the coast of Africa, phosphorite-bearing sediments have been explored, but their development is not yet profitable. The total mass of phosphorites on the continental shelf is estimated at 300 billion tons. Large fields of ferromanganese nodules have been found at the bottom of the North American Basin and on the Blake Plateau, their total reserves in the Arctic Ocean. are estimated at 45 billion tons.
Recreational resources
From the 2nd half. 20th century The use of ocean recreational resources is of great importance for the economies of coastal countries. Old resorts are being developed and new ones are being built. Since the 1970s ocean liners are being built, intended only for cruises; they are distinguished by their large size (displacement of 70 thousand tons or more), increased level of comfort and relative slowness. Basic routes of cruise ships A. o. – Mediterranean and Caribbean Seas and the Mexican Hall. From the end 20 – beginning 21st centuries Scientific tourism 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, the Caribbean and the Gulf of Mexico.
Energy
Energy sea tides A. o. is estimated at approximately 250 million kW. In the Middle Ages, mills and sawmills were built in England and France using tidal waves. At the mouth of the river Rance (France) operates a tidal power plant. The use of ocean hydrothermal energy (temperature differences in surface and deep waters) is also considered promising; a hydrothermal station operates on the coast of Côte d’Ivoire.
Port cities
On the shores of A. o. most are located major ports world: 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; 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. Ross. port cities do not have direct access to the Arctic Ocean. and are located on the banks of the inland. seas belonging to its basin: St. Petersburg, Kaliningrad, Baltiysk (Baltic Sea), Novorossiysk, Tuapse (Black Sea).
Huge bodies of water The planets that cover most of it and the surrounding islands and continents are called oceans. Among them, the largest are Atlantic and Pacific. These are two giants that people don’t know everything about. Humanity knows where the Atlantic Ocean is, what its boundaries are, underwater inhabitants, relief, etc.
Atlantic Ocean
The Atlantic Ocean is considered the second largest after the Pacific. However, it is better studied and developed in comparison with other water areas. Where is the Atlantic Ocean, what are its boundaries? This giant is located along the length of the entire planet: in the east the border is North and South America, in the west - Europe and Africa. In the south, the Atlantic waters flow into the Southern Ocean. In the north, the giant is limited to Greenland.
In those places where the Atlantic Ocean is located, there are practically no islands, which distinguishes this water area from others. Another distinctive feature is the complex bottom topography and broken coastline.
Atlantic Ocean parameters
If we talk about the area, the water area occupies more than ninety million square kilometers. Where the Atlantic Ocean is located, huge water reserves are concentrated. According to scientists, there are almost 330 million cubic kilometers of water in this basin.
The Atlantic Ocean is quite deep - the average depth reaches 3800 meters. Where the Puerto Rico Trench is located, the depth exceeds eight kilometers.
The Atlantic Ocean is divided into two parts: northern and southern. The conventional border between them runs along the equator.
Bays, seas and currents
The area of seas and bays accounts for about sixteen percent of the total ocean area: approximately fifteen million square kilometers, with a volume of thirty million cubic kilometers. The most famous seas The Atlantics are: North, Mediterranean, Aegean, Black, Azov, Caribbean, Labrador Sea, Baltic. By the way, where is the Baltic Sea in the Atlantic Ocean? It is located near the Northern Arctic Circle, at 65°40" N latitude ( northern point), and in the south the sea is defined by the border with coordinates 53 ° 45 "N, located near Wismar. In the west, the border is located at Flensburg, in the east - in the St. Petersburg region.
Many people are interested in the question: “Where is the North Atlantic Current located in the Atlantic Ocean and what other currents are there?” The ocean is huge and stretches from north to south, across all hemispheres. Because of this location, different areas have different climates. But not only the proximity of the poles affects the weather: it is also influenced by currents that carry large volumes ocean waters. Thanks to them, the west is warmer than the eastern part. This feature is associated with the Gulf Stream and its branches - the Antilles, Brazil, and North Atlantic. In the eastern part there is not only a warm current, but also a cold one - the Bengal and Canary.
The North Atlantic Current is the northeastern continuation of the Gulf Stream. It starts at the Great Newfoundland Gully. West of Ireland the current is divided into two parts, one of which is the Canary.
Northern part of the ocean
The northern edge of the Atlantic has an indented coastline. A small part has a connection with the Arctic Ocean: it is connected to it by several narrow straits. In the northeast is the Davis Strait, connecting the Baffin Sea with the ocean. Closer to the center of the northern border is the Denmark Strait, and between Norway and Iceland the Norwegian Sea serves as the border.
In the southwest of the North Atlantic Ocean is the Gulf of Mexico, connected to the Gulf of Florida. Also in this part is the Caribbean Sea. And besides, many other famous bays: Hudson, Barnegat, etc. The largest islands are located in this part of the basin: Cuba, Haiti, the British Isles. There are also island groups closer to the east, but they are small. Among them, the most popular are the Canary Islands, the Azores Islands, and Cape Verde. Closer to the west are the Bahamas.
Southern part of the water area
The southern boundaries of the ocean are not as indented as in the northern part. There are no seas here, but there is a very large Gulf of Guinea. The most remote point of the Atlantic in the south is Tierra del Fuego, framed by small islands.
There are no large islands in the southern part of the ocean, but there are separately located formations. An example is the islands of Ascension and Saint Helena.
There are also currents in the south, but here the waters move counterclockwise. The most powerful and largest current in this part is the South Trade Wind, which branches off the coast of Brazil. One of its branches goes to the shores of South America, and the second connects with the Atlantic Current and moves east, where part of the current separates and passes into the Bengal Current.
There are two huge oceans on Earth, and knowing where the Pacific and Atlantic oceans are, we can say for sure that these two great natural creatures will never meet.
The Atlantic Ocean basin includes the inland seas of Azov, Black and Baltic. Communication with the ocean is carried out through narrow straits. Insignificant water exchange with open areas water areas and rivers are caused by desalination, which is especially characteristic of the Baltic Sea. All this affects the biodiversity of the seas and the state of their ecosystems. The seas are characterized by low activity; the Black Sea is non-freezing. The Atlantic waters have important transport and recreational functions, and therefore in some of their areas there are hotbeds of environmental tension.The Sea of Azov washes the southwestern borders of Russia and is the shallowest sea on the planet (Fig. 45). His maximum depth is 13.5 m. According to morphological characteristics, it belongs to flat seas, and according to its distance from the ocean, it is the most continental sea on the planet.
According to the treaty between Russia and Ukraine, ratified in 2004, the sea is classified as inland waters these states.
The relief is quite simple and is characterized by a smooth increase in depth. The location of the isobaths is close to symmetrical. The coasts are mostly sandy and smooth, but in some places there are hills that turn into steep rock formations.
The sea is located in the zone of temperate latitudes, which is reflected in the climate. IN winter time The Siberian anticyclone, which determines low temperatures and strong winds, has a great influence on weather conditions. The summer period is predominantly dry and characterized by fairly high temperatures.
The salinity of the sea differs sharply from medium salinity ocean and depends on river flow, accounting for up to 12% of the water volume. In the area of the Kerch Strait, salinity is about 11.5%.
Currents strongly depend on the wind regime, as a result of which their direction is not constant. The circular current is directed counterclockwise in the central part of the water area.
Freeze-up begins at the end of November, but ice formation is irregular, depending on the temperature regime. In the most severe winters, the ice thickness can reach 90 cm. Complete clearing of ice occurs in mid-March.
Species diversity is insignificant. The ichthyofauna includes 103 species. The most valuable commercial anadromous species are beluga, stellate sturgeon, herring, vimba and shemaya. Among the marine species, pelengas, sprat, glossa, red mullet, horse mackerel, and mackerel stand out. Marine mammals are represented by only one species - the porpoise (Azov) - the smallest mammal from the group of cetaceans. Regarding the quantitative composition of flora and fauna, the Sea of Azov stands out among all the seas of the World Ocean. In terms of fish productivity, it exceeds the Black Sea by 40 times, and the Mediterranean by 160 times.
Beluga is one of the largest and longest living fish. Lives in the Azov, Black, Caspian seas. In 1939, a female beluga weighing 750 kg was caught in the Temryuk Gulf of the Sea of Azov.
Economic activity on the coast is very developed. Fishing and recreational activities are distinguished. The sea is experiencing negative pressure in the coastal area, and the situation is especially critical near industrial centers. Transport activities, including the transportation of petroleum products, have a great impact on the water area.
The Black Sea also belongs to inland seas Atlantic Ocean and washes the southern regions of Russia. Through the Bosphorus Strait it connects with the Sea of Marmara and is the border between Europe and Asia Minor. Among all the seas washing Russian Federation The Black Sea is distinguished by the fact that it is the world's largest meromictic reservoir; at depths of more than 150-200 m, due to saturation with hydrogen sulfide, the concentration of which reaches 14 mg/l, there is practically no life.
The coastline is slightly indented; the Russian part of the Black Sea section is characterized by a wide shelf strip. The sediments are dominated by coarse rocks: pebbles, gravel, which with depth are replaced by fine-grained sands and silt.
The climate is predominantly continental; southeast of Tuapse it is humid subtropical. The weather is greatly influenced by cyclonic masses formed in the Atlantic. The spurs of the mountains are not a barrier to the cold northern air masses, which causes a strong cold wind(boron). The region is characterized by warm, humid winters and hot, dry summers.
In the pattern of currents, two closed gyres stand out, in the oceanographic literature called “Knipovich Points” after the oceanologist Nikolai Knipovich, who first described the pattern of currents in the Black Sea. The small size of the water area and its isolation determine insignificant tides. However, surge phenomena are well expressed.
The surface layer of water has a salinity of about 18%o, which increases with depth to 22.5%o.
A mild climate is usually not conducive to ice formation. However, during very severe and long winters, the sea can become covered with ice near the coast, which happens no more than once every few decades.
The Black Sea is home to about 2,500 species of organisms, of which about 160 species of fish, 500 species of crustaceans, 200 species of mollusks.
The sea dragon (scorpion fish, snake fish) (Fig. 46) is the most poisonous fish that lives in the Black Sea in shallow water with a sandy and muddy bottom. Due to their hidden lifestyle and aggressiveness, dragonets are very dangerous to anyone who disturbs them.
The sea area has important recreational, fishing, and transport significance. Black Sea ports are the end points of pan-European transport corridors. Among environmental problems pollution from petroleum products, ballast water and chemicals is released.
The Baltic Sea washes the northwestern coast of Russia and is located within the continental shelf (Fig. 47). The sea is characterized by significant ruggedness coastline, the presence of numerous islands and great desalination. 
The bottom is heterogeneous; in the coastal part there are sands, which are replaced with depth by silty deposits of glacial origin.
The climate is formed under the influence of the Atlantic Ocean and is defined as a maritime climate of temperate latitudes. The region is characterized by cloudy, humid weather.
A special feature of the hydrological regime is the large influx of fresh water brought by the rivers flowing into the water area. Surface water circulation is generally counterclockwise, but winds can influence current directions. Tides in the Baltic Sea are semidiurnal and diurnal, but insignificant, their value does not exceed 20 cm.
The waters are characterized by significant desalination. In the Gulf of Finland, salinity does not exceed 2%o; in open waters it increases to 20%o. Freeze-up begins in October - November. During one winter, ice can melt and freeze again. Off the coast Gulf of Finland The thickness of the fast ice reaches 65 cm. Open water areas usually remain ice-free.
Amber - the most valuable wealth of the Baltic Sea - according to legend, is the remains of the ruined palace of the sea goddess Jurate. So the mighty Perkunas, the god of Thunder, punished her for her love for the simple fisherman Kastitis. The origin of amber is more prosaic. This is the frozen resin of coniferous trees that once grew here.
The greatest importance of the Baltic Sea is transport. At the same time, fishing is also widely developed. Here they catch herring, sprat, lamprey, whitefish and other types of fish. The state of the Baltic Sea ecosystems is in a depressed state. This is due to excess anthropogenic load. A burial took place in the water area chemical weapons. A lot of ammunition has been preserved from World War II. Significant pollution with petroleum products.
It should be noted that the situation in almost all the seas washing Russia is far from favorable. Several problems can be identified that are common to all marine areas. Among them:
. depletion of biological resources associated with overfishing and poaching;
. pollution of water areas with oil and oil products;
. radiation pollution, especially in the northern seas;
. global climate warming leading to qualitative
changes in marine ecosystems. Rational environmental management and management biological resources should be based on ecosystem studies, on knowledge of key connections and patterns of their functioning.
Questions for self-control
1. The concept of population. Features of hydrobiont populations.
2. Population size and density.
3. The concept of medium capacity.
4. Chorological structure and territoriality in hydrobiocenosis.
5. Age and ethological structure of the population.
6. Sexual and generative structure of the population.
7. Features of the dynamics of hydrobiont populations.
8. Characteristics of forms of placement and population growth.
9. The concept of biotic potential.
10. Mortality and survival of individuals in populations of aquatic organisms.
11. Hydrobiocenosis and its structure.
12. Characteristics of the species and size structure of hydrobiocenosis.
13. Trophic structure of hydrobiocenosis.
14. Features of the functioning of hydrobiocenosis.
15. Nutrition and respiration of hydrobionts.
16. Dynamics of hydrobiocenoses.
17. Features of marine ecosystems.
18. Characteristics of continental shelf ecosystems.
19. Characteristics of pelagic and deep-sea benthic ecosystems.
20. general characteristics seas of the Pacific Ocean.
21. General characteristics of the seas of the Arctic Ocean.
22. General characteristics of the seas of the Atlantic Ocean.