Where is the Atlantic Ocean located? Characteristics of the ocean, North and South Atlantic oceans. largest seas

The Atlantic Ocean is the second largest ocean on Earth after the Pacific Ocean, located between Greenland and Iceland in the north, Europe and Africa in the east, North and South America in the west, and Antarctica in the south.

The area is 91.6 million km², of which about a quarter falls on the inland seas. The area of coastal seas is small and does not exceed 1% of the total water area. The volume of water is 329.7 million km³, which is equal to 25% of the volume of the World Ocean. The average depth is 3736 m, the greatest is 8742 m (Puerto Rico Trench). The average annual salinity of the ocean waters is about 35 ‰. The Atlantic Ocean has a strongly indented coastline with a pronounced division into regional water areas: seas and bays.

The name comes from the name of the titan Atlas (Atlanta) in Greek mythology.

Characteristics:

Area - 91.66 million km²
Volume - 329.66 million km³
The greatest depth - 8742 m
Average depth - 3736 m

Etymology

The name of the ocean is first encountered in the 5th century BC. e. in the writings of the ancient Greek historian Herodotus, who wrote that "the sea with the pillars of Hercules is called Atlantis (ancient Greek Ἀτλαντίς - Atlantis)". The name comes from the ancient Greek myth of Atlanta, a titan holding the vault of heaven on his shoulders at the extreme western point of the Mediterranean. The Roman scientist Pliny the Elder in the 1st century used the modern name Oceanus Atlanticus (lat. Oceanus Atlanticus) - “Atlantic Ocean”. At different times, separate parts of the ocean were called the Western Ocean, the North Sea, the Outer Sea. Since the middle of the 17th century, the Atlantic Ocean has become the only name referring to the entire water area.

Physical and geographical characteristics

General information

The Atlantic Ocean is the second largest. Its area is 91.66 million km², the volume of water is 329.66 million km³. It extends from the subarctic latitudes to Antarctica itself. The border with the Indian Ocean runs along the meridian of Cape Agulhas (20° E) to the coast of Antarctica (Queen Maud Land). The border with the Pacific Ocean is drawn from Cape Horn along the meridian 68 ° 04 'W. or the shortest distance from South America to the Antarctic Peninsula through the Drake Passage, from Oste Island to Cape Sternek. The border with the Arctic Ocean passes along the eastern entrance of the Hudson Strait, then through the Davis Strait and along the coast of Greenland Island to Cape Brewster, through the Denmark Strait to Cape Reidinupur on the island of Iceland, along its coast to Cape Gerpir, then to the Faroe Islands, then to Shetland islands and along 61 ° north latitude to the coast of the Scandinavian Peninsula. Sometimes the southern part of the ocean, with a northern boundary of 35 ° S. sh. (on the basis of the circulation of water and the atmosphere) up to 60 ° S. sh. (according to the nature of the bottom topography), they are attributed to the Southern Ocean, which is not officially distinguished.

Seas and bays

The area of the seas, bays and straits of the Atlantic Ocean is 14.69 million km² (16% of the total ocean area), the volume is 29.47 million km³ (8.9%). Seas and main bays (clockwise): Irish Sea, Bristol Bay, North Sea, Baltic Sea (Gulf of Bothnia, Gulf of Finland, Gulf of Riga), Bay of Biscay, Mediterranean Sea (Alboran Sea, Balearic Sea, Ligurian Sea, Tyrrhenian Sea, Adriatic Sea, Ionian Sea, Aegean Sea), Sea of Marmara, Black Sea, Sea of Azov, Gulf of Guinea, Riiser-Larsen Sea, Lazarev Sea, Weddell Sea, Scotia Sea (the last four are sometimes referred to as the Southern Ocean), Caribbean Sea, Gulf of Mexico , Sargasso Sea, Gulf of Maine, Gulf of Saint Lawrence, Labrador Sea.

Islands

The largest islands and archipelagos of the Atlantic Ocean: the British Isles (Great Britain, Ireland, the Hebrides, Orkney Islands, Shetland Islands), the Greater Antilles (Cuba, Haiti, Jamaica, Puerto Rico, Huventud), Newfoundland, Iceland, the Tierra del Fuego archipelago (Fire Land, Oste, Navarino), Marajo, Sicily, Sardinia, Lesser Antilles (Trinidad, Guadeloupe, Martinique, Curacao, Barbados, Grenada, St. Vincent, Tobago), Falkland (Malvinas) Islands (East Falkland (Soledad), West Falkland (Gran Malvina)), Bahamas (Andros, Grand Inagua, Grand Bahama), Cape Breton, Cyprus, Corsica, Crete, Anticosti, Canary Islands (Tenerife, Fuerteventura, Gran Canaria), Zeeland, Prince Edward, Balearic Islands (Mallorca), South Georgia, Long Island, Moonsund Archipelago (Saaremaa, Hiiumaa), Cape Verde Islands, Euboea, Southern Sporades (Rhodes), Gotland, Funen, Cyclades, Azores, Ionian Islands, South Shetland Islands, B Yoko, Bijagos Islands, Lesvos, Aland Islands, Faroe Islands, Öland, Lolland, South Orkney Islands, Sao Tome, Madeira Islands, Malta, Principe, Saint Helena, Ascension, Bermuda.

History of ocean formation

The Atlantic Ocean was formed in the Mesozoic as a result of the split of the ancient supercontinent Pangea into the southern continent of Gondwana and northern Laurasia. As a result of the multidirectional movement of these continents at the very end of the Triassic, it led to the formation of the first oceanic lithosphere of the current North Atlantic. The resulting rift zone was the western continuation of the rift crack in the Tethys Ocean. The Atlantic basin at an early stage of its development was formed as a connection of two large ocean basins of the Tethys Ocean in the east and the Pacific Ocean in the west. Further expansion of the Atlantic Ocean basin will take place due to the reduction in the size of the Pacific Ocean. In the early Jurassic, Gondwana began to split into Africa and South America, and the oceanic lithosphere of the modern South Atlantic was formed. During the Cretaceous, Laurasia split apart, and the separation of North America from Europe began. At the same time, Greenland, shifting to the north, broke away from Scandinavia and Canada. During the last 40 million years and up to the present time, the opening of the Atlantic Ocean basin continues along a single rift axis located approximately in the middle of the ocean. Today, the movement of tectonic plates continues. In the South Atlantic, the divergence of the African and South American plates continues at a rate of 2.9-4 cm per year. In the Central Atlantic, the African, South American and North American plates diverge at a rate of 2.6-2.9 cm per year. In the North Atlantic, the spreading of the Eurasian and North American plates continues at a rate of 1.7-2.3 cm per year. The North American and South American plates are moving to the west, the African to the northeast, and the Eurasian to the southeast, forming a compression belt in the Mediterranean Sea.

Geological structure and bottom topography

Underwater margins of the continents

Significant areas of the shelf are confined to the northern hemisphere and are adjacent to the coasts of North America and Europe. In Quaternary times, most of the shelf was subjected to continental glaciation, which formed relic glacial landforms. Another element of the relict relief of the shelf is flooded river valleys, which are found in almost all shelf regions of the Atlantic Ocean. Relic continental deposits are widespread. Off the coast of Africa and South America, the shelf occupies smaller areas, but in the southern part of South America it expands significantly (Patagonian shelf). Tidal currents have formed sandy ridges, which are the most widespread of modern subaqueous landforms. They are very characteristic of the shelf North Sea, they are found in large numbers in the English Channel, as well as on the shelves of North and South America. In equatorial-tropical waters (especially in the Caribbean Sea, on the Bahamas, off the coast of South America), coral reefs are diverse and widely represented.

Continental slopes in most areas of the Atlantic Ocean are expressed by steep slopes, sometimes having a stepped profile and deeply dissected by submarine canyons. In some areas, continental slopes are supplemented by marginal plateaus: Blake, São Paulo, Falkland on the American submarine margins; Podkupain and Goban on the underwater outskirts of Europe. The blocky structure is the Farrero-Iceland threshold, which extends from Iceland to the North Sea. In the same region is the Rokkol Upland, which is also a submerged part of the underwater part of the European subcontinent.

The continental foot, for most of its length, is an accumulation plain lying at a depth of 3-4 km and composed of a thick (several kilometers) thickness of bottom sediments. Three rivers of the Atlantic Ocean are among the ten largest in the world - Mississippi (solid runoff 500 million tons per year), Amazon (499 million tons) and Orange (153 million tons). The total volume of sedimentary material carried annually into the Atlantic Ocean basin by only 22 of its main rivers is more than 1.8 billion tons. Large fans of turbidity flows are located in certain areas of the continental foot, among them the most significant fans of the submarine canyons of the Hudson, Amazon, Rhone (in the Mediterranean), Niger, Congo. Along the North American continental margin, due to the bottom runoff of cold Arctic waters along the continental foot, giant accumulation landforms are formed in a southerly direction (for example, the "sedimentary ridges" of Newfoundland, Blake-Bahama and others).

transition zone

Transitional zones in the Atlantic Ocean are represented by areas: the Caribbean, the Mediterranean and the area of the Scotia Sea or the South Sandwich.

The Caribbean region includes: the Caribbean Sea, the deep-water part of the Gulf of Mexico, island arcs and deep-sea trenches. The following island arcs can be distinguished in it: Cuban, Cayman-Siera-Maestra, Jamaica-South Haiti, outer and inner arcs of the Lesser Antilles. In addition, the underwater height of Nicaragua, the Beata and Aves ridges are distinguished here. The Cuban arc has a complex structure and has a Laramian age of folding. Its continuation is the northern cordillera of the island of Haiti. The Cayman-Siera Maestra fold structure, which is of Miocene age, begins with the Maya mountains on the Yucatan Peninsula, then continues in the form of the Cayman submarine ridge and the Sierra Maestra mountain range of Southern Cuba. The Little Antilles arc includes a number of volcanic formations (including three volcanoes, for example, Montagne Pele). The composition of the eruption products: andesites, basalts, dacites. The outer ridge of the arc is limestone. From the south, the Caribbean Sea is bordered by two parallel young ridges: the arc of the Leeward Islands and the mountain range of the Caribbean Andes, passing to the east into the islands of Trinidad and Tobago. Island arcs and underwater ridges divide the bottom of the Caribbean Sea into several basins, which are leveled by a thick layer of carbonate bottom sediments. The deepest of them is Venezuelan (5420 m). There are also two deep-water trenches - Cayman and Puerto Rico (with the greatest depth of the Atlantic Ocean - 8742 m).

The areas of the Scotia Ridge and the South Sandwich Islands are borderlands - sections of the underwater continental margin, fragmented by tectonic movements of the earth's crust. The island arc of the South Sandwich Islands is complicated by a number of volcanoes. From the east, it adjoins the South Sandwich Deep Trench with a maximum depth of 8228 m. The mountainous and hilly topography of the bottom of the Scotia Sea is associated with the axial zone of one of the branches of the mid-ocean ridge.

In the Mediterranean Sea, there is a wide distribution of the continental crust. The suboceanic crust is developed only in spots in the deepest basins: Balearic, Tyrrhenian, Central and Cretan. The shelf is significantly developed only within the Adriatic Sea and the Sicilian threshold. The mountainous folded structure connecting the Ionian Islands, Crete and the islands to the east of the latter is an island arc, which is bounded from the south by the Hellenic trench, in turn from the south framed by the rise of the East Mediterranean shaft. The bottom of the Mediterranean Sea in the geological section is composed of salt-bearing strata of the Messinian stage (Upper Miocene). The Mediterranean Sea is a seismic zone. Several active volcanoes have been preserved here (Vesuvius, Etna, Santorini).

Mid-Atlantic Ridge

The meridional Mid-Atlantic Ridge divides the Atlantic Ocean into eastern and western parts. It begins off the coast of Iceland under the name of the Reykjanes Range. Its axial structure is formed by a basalt ridge, rift valleys are poorly expressed in the relief, but active volcanoes are known on the flanks. At a latitude of 52-53 ° N the mid-ocean ridge is crossed by the transverse zones of the Gibbs and Reykjanes faults. Behind them begins the Mid-Atlantic Ridge with a clearly defined rift zone and rift valleys with numerous transverse faults and deep grabens. At latitude 40°N the mid-ocean ridge forms the Azores volcanic plateau, with numerous above-water (forming islands) and underwater active volcanoes. To the south of the Azores Plateau, in the rift zone, under calcareous muds 300 m thick, basalts occur, and beneath them is a blocky mixture of ultrabasic and basic rocks. In this area, modern violent volcanic and hydrothermal activity is observed. In the equatorial part, the North Atlantic Ridge is divided by a large number of transverse faults into a number of segments experiencing significant (up to 300 km) lateral displacements relative to each other. Near the equator, the Romansh depression is connected with deep-water faults with depths up to 7856 m.

The South Atlantic Ridge has a meridional strike. Rift valleys are well expressed here, the number of transverse faults is less, so this ridge looks more monolithic compared to the North Atlantic Ridge. In the southern and middle parts of the ridge, the volcanic plateaus of the Ascension, the islands of Tristan da Cunha, Gough, and Bouvet stand out. The plateau is confined to active and recently active volcanoes. From Bouvet Island, the South Atlantic Ridge turns east, goes around Africa and merges with the West Indian Mid-Range in the Indian Ocean.

Ocean bed

The Mid-Atlantic Ridge divides the bed of the Atlantic Ocean into two almost equal parts. In the western part, mountain structures: the Newfoundland Range, the Baracuda Range, the Ceara and Rio Grande rises divide the ocean bed into basins: Labrador, Newfoundland, North American, Guiana, Brazilian, Argentine. To the east of the mid-ocean ridge, the bed is divided by the underwater base of the Canary Islands, the uplift of the Cape Verde Islands, the Guinea uplift and the Whale Ridge into basins: the Western European, Iberian, North African, Cape Verde, Sierra Leone, Guinea, Angolan, Cape. In the basins, flat abyssal plains are widespread, composed mainly of calcareous biogenic, as well as terrigenous material. Over most of the area of the ocean floor, the thickness of precipitation is more than 1 km. Under the sedimentary rocks, a layer was found represented by volcanic rocks and compacted sedimentary rocks.

Abyssal hills are widespread along the periphery of mid-ocean ridges in areas of basins remote from the submarine margins of continents. About 600 mountains are located within the ocean floor. A large group of seamounts is confined to the Bermuda Plateau (in the North American Basin). There are several large submarine valleys, of which the most significant are the Hazen and Maury valleys in the northern part of the Atlantic Ocean floor, stretching on both sides of the Mid-Ocean Ridge.

Bottom sediments

The sediments of the shallow part of the Atlantic Ocean are mostly represented by terrigenous and biogenic sediments, and occupy 20% of the ocean floor area. Of the deep-sea deposits, calcareous foraminiferal silts are the most common (65% of the ocean floor area). In the Mediterranean and Caribbean Seas, in the southern zone of the South Atlantic Ridge, pteropod deposits have become widespread. Deep-water red clay occupies about 20% of the ocean floor area and is confined to the deepest parts of oceanic basins. Radilarian muds are found in the Angolan Basin. In the southern part of the Atlantic, siliceous diatom deposits are presented with an authigenic silica content of 62-72%. In the zone of the Current of the Western Winds, a continuous field of diatomaceous oozes extends, with the exception of the Drake Passage. In some basins of the ocean floor, terrigenous silts and pelites are significantly developed. Terrigenous deposits at abyssal depths are characteristic of the North Atlantic, Hawaiian, and Argentine basins.

Climate

The variety of climatic conditions on the surface of the Atlantic Ocean is determined by its large meridional extent and the circulation of air masses under the influence of four main atmospheric centers: the Greenland and Antarctic highs, and the Icelandic and Antarctic lows. In addition, two anticyclones constantly operate in the subtropics: Azores and South Atlantic. They are separated by an equatorial region of low pressure. This distribution of baric regions determines the system of prevailing winds in the Atlantic. The greatest influence on the temperature regime of the Atlantic Ocean is exerted not only by its large meridional extent, but also by water exchange with the Arctic Ocean, the seas of the Antarctic and the Mediterranean Sea. Surface waters are characterized by their gradual cooling as they move away from the equator to high latitudes, although the presence of powerful currents causes significant deviations from zonal temperature regimes.

All the climatic zones of the planet are represented in the vastness of the Atlantic. Tropical latitudes are characterized by slight seasonal temperature fluctuations (average - 20 ° C) and heavy rainfall. To the north and south of the tropics are subtropical zones with more noticeable seasonal (from 10 ° C in winter to 20 ° C in summer) and daily temperature fluctuations; Precipitation here falls mainly in summer. Tropical hurricanes are a frequent occurrence in the subtropical zone. In these monstrous atmospheric eddies, wind speeds reach several hundred kilometers per hour. The most powerful tropical hurricanes rage in the Caribbean: for example, in the Gulf of Mexico and the West Indies. West Indian tropical hurricanes form in the western part of the ocean around 10-15°N. and move to the Azores and Ireland. Further to the north and south, the subtropical zones follow, where in the coldest month the temperature drops to 10 ° C, and in winter cold air masses from the polar regions of low pressure bring heavy precipitation. In temperate latitudes, the average temperature of the warmest month is kept within 10-15 °C, and the coldest -10 °C. Significant diurnal temperature fluctuations are also noted here. The temperate zone is characterized by fairly even precipitation throughout the year (about 1,000 mm), reaching a maximum in the autumn-winter period, and frequent fierce storms, for which the southern temperate latitudes are nicknamed the “roaring forties”. The 10 °C isotherm defines the boundaries of the Northern and Southern Subpolar Belts. In the Northern Hemisphere, this boundary runs in a wide strip between 50°N. (Labrador) and 70°N. (Northern Norway coast). In the Southern Hemisphere, the subpolar zone begins closer to the equator - approximately 45-50°S. The lowest temperature (-34 °C) was recorded in the Weddell Sea.

Hydrological regime

Surface water circulation

Powerful carriers of thermal energy are circular surface currents, located on both sides of the equator: such, for example, are the North Trade Wind and South Trade Wind currents that cross the ocean from east to west. The Northern Tradewind Current near the Lesser Antilles is divided: into a northern branch continuing northwest along the shores of the Greater Antilles (Antilles current) and into a southern branch leaving through the straits of the Lesser Antilles into the Caribbean Sea, and then flows through the Yucatan Strait into the Gulf of Mexico, and leaves it through the Florida Strait, forming the Florida Current. The latter has a speed of 10 km / h and gives rise to the famous Gulf Stream. The Gulf Stream, following along the American coast, at 40°N. as a result of the influence of westerly winds and the Coriolis force, it acquires an easterly and then northeasterly direction and is called the North Atlantic Current. The main flow of waters of the North Atlantic Current passes between Iceland and the Scandinavian Peninsula and flows into the Arctic Ocean, softening the climate in the European sector of the Arctic. Two powerful streams of cold desalinated water flow out of the Arctic Ocean - the East Greenland Current, which runs along the eastern coast of Greenland, and the Labrador Current, which envelops Labrador, Newfoundland and penetrates south to Cape Hatteras, pushing the Gulf Stream from the coast of North America.

The South Equatorial Current partially enters the northern hemisphere, and at Cape San Roque it is divided into two parts: one of them goes south, forming the Brazilian Current, the other turns north, forming the Guiana Current, which goes into the Caribbean Sea. The Brazilian Current in the La Plata region meets the cold Falkland Current (an offshoot of the West Wind Current). Near the southern end of Africa, the cold Benguela Current branches off from the West Wind Current and, moving along the coast of South West Africa, gradually deviates to the west. In the southern part of the Gulf of Guinea, this current closes the anticyclonic circulation of the South Trade Wind Current.

There are several layers of deep currents in the Atlantic Ocean. A powerful countercurrent passes under the Gulf Stream, the main core of which lies at a depth of up to 3500 m, with a speed of 20 cm/s. The countercurrent flows in a narrow stream in the lower part of the continental slope, the formation of this current is associated with the bottom runoff of cold waters from the Norwegian and Greenland seas. In the equatorial zone of the ocean, the Lomonosov subsurface current has been discovered. It starts from the Antilo-Guiana countercurrent and reaches the Gulf of Guinea. The powerful deep Louisiana current is observed in the eastern part of the Atlantic Ocean, formed by the bottom runoff of saltier and warmer Mediterranean waters through the Strait of Gibraltar.

The greatest tide values are confined to the Atlantic Ocean, which are noted in the fjord bays of Canada (in Ungava Bay - 12.4 m, in Frobisher Bay - 16.6 m) and Great Britain (up to 14.4 m in Bristol Bay). The highest tide in the world is recorded in the Bay of Fundy, on the east coast of Canada, where the maximum tide reaches 15.6-18 m.

Temperature, salinity, ice formation

The temperature fluctuation of the Atlantic waters during the year is not large: in the equatorial-tropical zone - no more than 1-3 °, in the subtropics and temperate latitudes - within 5-8 °, in polar latitudes - about 4 ° in the north and not more than 1 ° on South. The warmest waters are in the equatorial and tropical latitudes. For example, in the Gulf of Guinea, the temperature in the surface layer does not drop below 26 °C. In the northern hemisphere, north of the tropics, the temperature of the surface layer decreases (at 60°N it is 10°C in summer). In the southern hemisphere, temperatures rise much faster and by 60°S. hover around 0°C. In general, the ocean in the southern hemisphere is colder than in the northern. In the northern hemisphere, the western part of the ocean is colder than the eastern one, and vice versa in the southern hemisphere.

The highest salinity of surface waters in the open ocean is observed in the subtropical zone (up to 37.25 ‰), and the maximum in the Mediterranean Sea is 39 ‰. In the equatorial zone, where the maximum amount of precipitation is noted, salinity decreases to 34 ‰. A sharp desalination of water occurs in the estuarine areas (for example, at the mouth of La Plata 18-19 ‰).

Ice formation in the Atlantic Ocean occurs in the Greenland and Baffin Seas and Antarctic waters. The main source of icebergs in the South Atlantic is the Filchner Ice Shelf in the Weddell Sea. On the Greenland coast, icebergs are produced by outlet glaciers, such as the Jakobshavn Glacier near Disko Island. Floating ice in the northern hemisphere reaches 40°N in July. In the southern hemisphere, floating ice is present throughout the year up to 55°S, reaching its maximum distribution in September-October. The total removal from the Arctic Ocean is estimated at an average of 900,000 km³/year, from the surface of Antarctica - 1630 km³/year.

water masses

Under the influence of wind and convective processes, vertical mixing of water occurs in the Atlantic Ocean, covering a surface thickness of 100 m in the southern hemisphere and up to 300 m in the tropics and equatorial latitudes. Below the layer of surface waters, outside the subantarctic zone, in the Atlantic there is the Antarctic intermediate water, which is almost universally identified with the intermediate minimum of salinity and is characterized by a higher content of biogenic elements in relation to the overlying waters, and extends northward to the region of 20° N. latitude. at depths of 0.7-1.2 km.

A feature of the hydrological structure of the eastern part of the North Atlantic is the presence of an intermediate Mediterranean water mass, which gradually descends to a depth of 1000 to 1250 m, turning into a deep water mass. In the southern hemisphere, this water mass descends to 2500-2750 m and wedged south of 45°S. The main feature of these waters is high salinity and temperature in relation to the surrounding waters. In the bottom layer of the Strait of Gibraltar, salinity is up to 38 ‰, temperature is up to 14 °C, but already in the Gulf of Cadiz, where Mediterranean waters reach the depths of their existence in the Atlantic Ocean, their salinity and temperature, as a result of mixing with background waters, decrease to 36 ‰ and 12-13°C, respectively. At the periphery of the distribution area, its salinity and temperature are, respectively, 35 ‰ and about 5°C. Under the Mediterranean water mass in the northern hemisphere, the North Atlantic deep water is formed, which sinks as a result of winter cooling of relatively saline waters in the North European Basin and the Labrador Sea to a depth of 2500-3000 m in the northern hemisphere and to 3500-4000 m in the southern hemisphere, reaching to about 50°S The North Atlantic deep water differs from the above and below Antarctic waters in its increased salinity, temperature and oxygen content, as well as a reduced content of nutrients.

The Antarctic bottom water mass is formed on the Antarctic slope by mixing cold and heavy Antarctic shelf water with lighter, warmer and more saline Circumpolar Deep Waters. These waters, spreading from the Weddell Sea, passing through all orographic obstacles up to 40 ° N, have a temperature of less than minus 0.8 ° C in the north of this sea, 0.6 ° C near the equator and 1.8 ° C near Bermuda. The Arctic bottom water mass has lower salinity values compared to the overlying waters, and in the South Atlantic it is characterized by an increased content of biogenic elements.

Flora and fauna

The bottom flora of the northern part of the Atlantic is represented by brown (mainly fucoids, and in the subtidal zone - kelp and alaria) and red algae. In the tropical zone, green (caulerpa), red (calcareous lithotamnia) and brown algae (sargasso) predominate. In the southern hemisphere, bottom vegetation is mainly represented by kelp. Phytoplankton of the Atlantic Ocean has 245 species: peridine, coccolithophorids, diatoms. The latter have a clearly defined zonal distribution; their maximum number lives in temperate latitudes of the northern and southern hemispheres. The most dense population of diatoms is in the strip of the Current of the Western Winds.

The distribution of the fauna of the Atlantic Ocean has a pronounced zonal character. In the subantarctic and antarctic waters, notothenia, blue whiting and others are of commercial importance from fish. Benthos and plankton in the Atlantic are poor in both species and biomass. In the subantarctic zone and in the adjacent zone of the temperate zone, the biomass reaches its maximum. In zooplankton, copepods and pteropods predominate; in nekton, whales (blue whales), pinnipeds, and their fish are nototheniids. In the tropical zone, zooplankton is represented by numerous species of foraminifera and pteropods, several species of radiolarians, copepods, larvae of molluscs and fish, as well as siphonophores, various jellyfish, large cephalopods (squids), and octopuses among benthal forms. Commercial fish are represented by mackerel, tuna, sardines, in areas of cold currents - anchovies. Corals are confined to tropical and subtropical zones. The temperate latitudes of the northern hemisphere are characterized by abundant life with a relatively small variety of species. Of the commercial fish, the most important are herring, cod, haddock, halibut, and sea bass. The most common zooplankton species are foraminifera and copepods. The greatest abundance of plankton is in the area of the Newfoundland Bank and the Norwegian Sea. The deep-sea fauna is represented by crustaceans, echinoderms, specific fish species, sponges, and hydroids. Several species of endemic polychaetes, isopods, and holothurians have been found in the Puerto Rico Trench.

Ecological problems

The Atlantic Ocean has been a place of intensive sea fishing and hunting since time immemorial. A sharp increase in capacity and a revolution in fishing technology have led to alarming proportions. With the invention of the harpoon gun in the North Atlantic, whales were largely exterminated as early as the end of the 19th century. In connection with the massive development of pelagic whaling in Antarctic waters in the middle of the 20th century, whales here were also close to complete extermination. Since the 1985-1986 season, the International Whaling Commission has introduced a complete moratorium on commercial whaling of any kind. In June 2010, at the 62nd meeting of the International Whaling Commission, under pressure from Japan, Iceland and Denmark, the moratorium was suspended.

The explosion on the Deepwater Horizon oil platform, owned by the British company BP, which occurred on April 20, 2010, is considered the largest environmental disaster that has ever occurred at sea. As a result of the accident, about 5 million barrels of crude oil spilled into the waters of the Gulf of Mexico, polluting 1,100 miles of coastline. The authorities introduced a ban on fishing, more than a third of the entire water area of the Gulf of Mexico is closed for fishing. As of November 2, 2010, 6,814 dead animals have been collected, including 6,104 birds, 609 sea turtles, 100 dolphins and other mammals, and 1 other reptile. According to the Office of Specially Protected Resources of the National Oceanic and Atmospheric Administration, in 2010-2011, an increase in the mortality of cetaceans in the northern Gulf of Mexico was several times higher than in previous years (2002-2009).

A large garbage patch of plastic and other waste has formed in the Sargasso Sea, formed by ocean currents, gradually concentrating garbage thrown into the ocean in one area.

In some areas of the Atlantic Ocean, radioactive contamination is observed. Wastes from nuclear power plants and research centers are dumped into rivers and coastal waters of the seas, and sometimes into deep oceans. The waters of the Atlantic Ocean heavily contaminated with radioactive waste include the North, Irish, Mediterranean Seas, the Gulf of Mexico, the Bay of Biscay and the Atlantic coast of the United States. In 1977 alone, 7180 containers containing 5650 tons of radioactive waste were dumped into the Atlantic. The US Environmental Protection Agency has reported seabed contamination 120 miles east of the Maryland-Delaware border. For 30 years, 14,300 cemented containers were buried there, which contained plutonium and cesium, radioactive contamination exceeded "expected" by 3-70 times. In 1970, the United States sank the Russell Brig, 500 km off the coast of Florida, carrying 68 tons of nerve gas (sarin) placed in 418 concrete containers. In 1972, in the waters of the ocean north of the Azores, Germany flooded 2,500 metal drums with industrial waste containing potent cyanide poisons. There are cases of rapid destruction of containers in the relatively shallow waters of the North and Irish Seas and the English Channel with the most detrimental consequences for the fauna and flora of the waters. 4 nuclear submarines sank in the waters of the North Atlantic: 2 Soviet (in the Bay of Biscay and the open ocean) and 2 American (off the US coast and in the open ocean).

States of the Atlantic Ocean

On the shores of the Atlantic Ocean and its constituent seas there are states and dependent territories:

In Europe (North to South): Iceland, Norway, Sweden, Finland, Russian Federation, Estonia, Latvia, Lithuania, Poland, Federal Republic of Germany, Denmark, Netherlands, Belgium, United Kingdom, Ireland, Isle of Man (UK), Jersey (UK possession), France, Spain, Portugal, Gibraltar (UK possession), Italy, Malta, Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Albania, Greece, Turkey, Bulgaria, Romania, Ukraine, Abkhazia (not recognized by the UN), Georgia;
In Asia: Cyprus, the Turkish Republic of Northern Cyprus (not recognized by the UN), Akrotiri and Dhekelia (possession of Great Britain), Syria, Lebanon, Israel, the Palestinian Authority (not recognized by the UN);
In Africa: Egypt, Libya, Tunisia, Algeria, Morocco, Saharan Arab Democratic Republic (not recognized by the UN), Mauritania, Senegal, Gambia, Cape Verde, Guinea-Bissau, Guinea, Sierra Leone, Liberia, Côte d'Ivoire , Ghana, Togo, Benin, Nigeria, Cameroon, Equatorial Guinea, Sao Tome and Principe, Gabon, Republic of the Congo, Angola, Democratic Republic of the Congo, Namibia, South Africa, Bouvet Island (Norwegian possession), Saint Helena, Ascension and Tristan da Cunha (British possession);
In South America (from south to north): Chile, Argentina, South Georgia and the South Sandwich Islands (UK possession), Falkland Islands (UK possession), Uruguay, Brazil, Suriname, Guyana, Venezuela, Colombia, Panama;
In the Caribbean: US Virgin Islands (U.S.), Anguilla (UK), Antigua and Barbuda, Bahamas, Barbados, British Virgin Islands (UK), Haiti, Grenada, Dominica, Dominican Republic, Cayman Islands (UK) , Cuba, Montserrat (UK), Navassa (US), Puerto Rico (US), Saint Vincent and the Grenadines, Saint Kitts and Nevis, St. Lucia, Turks and Caicos (UK), Trinidad and Tobago , Jamaica;
In North America: Costa Rica, Nicaragua, Honduras, Guatemala, Belize, Mexico, United States of America, Bermuda (UK), Canada.

History of the exploration of the Atlantic Ocean by Europeans

Long before the era of great geographical discoveries, numerous ships plied the Atlantic. As early as 4000 BC, the peoples of Phoenicia were engaged in maritime trade with the inhabitants of the islands of the Mediterranean Sea. At a later time, from the 6th century BC, the Phoenicians, according to the Greek historian Herodotus, made campaigns around Africa, and through the Strait of Gibraltar and around the Iberian Peninsula reached the British Isles. By the 6th century BC, Ancient Greece, having a military merchant fleet that was huge at that time, sailed to the shores of England and Scandinavia, in the Baltic Sea and to the western coast of Africa. In X-XI Art. The Vikings wrote a new page in the study of the North Atlantic Ocean. According to most researchers of pre-Columbian discoveries, the Scandinavian Vikings were the first to cross the ocean more than once, reaching the shores of the American continent (they called it Vinland) and discovering Greenland and Labrador.

In the 15th century, Spanish and Portuguese navigators began to make long voyages in search of routes to India and China. In 1488, the Portuguese expedition of Bartolomeu Dias reached the Cape of Good Hope and circled Africa from the south. In 1492, the expedition of Christopher Columbus mapped many islands of the Caribbean and the huge mainland, later called America. In 1497, Vasco da Gama passed from Europe to India, rounding Africa from the south. In 1520, Ferdinand Magellan, during the first circumnavigation of the world, passed through the Strait of Magellan from the Atlantic to the Pacific Ocean. At the end of the 15th century, the rivalry between Spain and Portugal for dominance in the Atlantic escalated so much that the Vatican was forced to intervene in the conflict. In 1494, an agreement was signed, which along the 48-49 ° west longitude established the so-called. papal meridian. All lands to the west of it were given to Spain, and to the east - to Portugal. In the 16th century, as the colonial wealth was being developed, the waves of the Atlantic began to regularly surf the ships carrying gold, silver, precious stones, pepper, cocoa and sugar to Europe. Weapons, fabrics, alcohol, food and slaves for cotton and sugar cane plantations were delivered to America in the same way. It is not surprising that in the XVI-XVII centuries. piracy and privateering flourished in these parts, and many famous pirates, such as John Hawkins, Francis Drake and Henry Morgan, entered their names into history. The southern border of the Atlantic Ocean (the continent of Antarctica) was discovered in 1819-1821 by the first Russian Antarctic expedition of F. F. Bellingshausen and M. P. Lazarev.

The first attempts to study the seabed were made in 1779 near the coast of Denmark, and the first Russian round-the-world expedition under the command of naval officer Ivan Krusenstern laid the foundation for serious scientific research in 1803-1806. Temperature measurements at various depths were carried out by J. Cook (1772), O. Saussure (1780), and others. Participants of subsequent trips measured the temperature and specific gravity of water at different depths, took samples of water transparency and established the presence of undercurrents. The collected material made it possible to draw up a map of the Gulf Stream (B. Franklin, 1770), a map of the depths of the northern part of the Atlantic Ocean (M.F. Maury, 1854), as well as maps of the winds and currents of the ocean (M.F. Maury, 1849-1860) and to carry out other research.

From 1872 to 1876, the first scientific oceanic expedition took place on the English sailing steam corvette Challenger, new data were obtained on the composition of the ocean waters, on the flora and fauna, on the bottom topography and soils, the first map of the depths of the ocean was compiled and the first collection was collected deep-sea animals, as a result of which extensive material was collected, published in 50 volumes. It was followed by expeditions on the Russian sail-propeller corvette "Vityaz" (1886-1889), on the German ships "Valdivia" (1898-1899) and "Gauss" (1901-1903) and others. The most important work was carried out on the British ship Discovery II (since 1931), thanks to which oceanographic and hydrobiological studies were carried out in the open part of the South Atlantic at great depths. Within the framework of the International Geophysical Year (1957-1958), international forces (especially the USA and the USSR) carried out research, as a result of which new bathymetric and marine navigation charts of the Atlantic Ocean were compiled. In 1963-1964, the Intergovernmental Oceanographic Commission conducted a major expedition to explore the equatorial and tropical zones of the ocean, in which the USSR took part (on the ships Vityaz, Mikhail Lomonosov, Akademik Kurchatov and others), the USA, Brazil and others countries.

In recent decades, numerous measurements of the ocean have been carried out from space satellites. The result was a bathymetric atlas of the oceans released in 1994 by the US National Geophysical Data Center with a map resolution of 3-4 km and a depth accuracy of ±100 m.

Economic importance

Fishing and marine industries

The Atlantic Ocean provides 2/5 of the world catch and its share decreases over the years. In subantarctic and antarctic waters, notothenia, blue whiting and others are of commercial importance, in the tropical zone - mackerel, tuna, sardine, in areas of cold currents - anchovies, in temperate latitudes of the northern hemisphere - herring, cod, haddock, halibut, sea bass. In the 1970s, due to overfishing of some species of fish, the volume of fishing fell sharply, but after the introduction of strict limits, fish stocks are gradually restored. Several international fisheries conventions operate in the Atlantic Ocean basin, which aim at the efficient and rational use of biological resources, based on the application of scientifically based measures to regulate fishing.

Transport routes

The Atlantic Ocean occupies a leading position in world shipping. Most of the routes lead from Europe to North America. The main navigable straits of the Atlantic Ocean: the Bosphorus and the Dardanelles, Gibraltar, the English Channel, Pas de Calais, the Baltic straits (Skagerrak, Kattegat, Øresund, Greater and Lesser Belt), Danish, Florida. The Atlantic Ocean is connected to the Pacific Ocean by the artificial Panama Canal dug between North and South America along the Isthmus of Panama, as well as to the Indian Ocean by the artificial Suez Canal through the Mediterranean Sea. The largest ports: St. Petersburg (general cargo, oil products, metals, timber, containers, coal, ore, chemical cargo, scrap metal), Hamburg (machinery and equipment, chemical products, raw materials for metallurgy, oil, wool, timber, food) , Bremen, Rotterdam (oil, natural gas, ores, fertilizers, equipment, food), Antwerp, Le Havre (oil, equipment), Felixstowe, Valencia, Algeciras, Barcelona, Marseille (oil, ore, grain, metals, chemicals, sugar , fruits and vegetables, wine), Gioia-Tauro, Marsaxlokk, Istanbul, Odessa (raw sugar, containers), Mariupol (coal, ore, grain, containers, oil products, metals, timber, food), Novorossiysk (oil, ore, cement, grain, metals, equipment, food), Batumi (oil, general and bulk cargo, food), Beirut (export: phosphorites, fruits, vegetables, wool, timber, cement, import: machinery, fertilizers, cast iron, building materials, food), Port Said, Alexandria (export: cotton, rice, ores, import: equipment, metals, oil products, fertilizers), Casablanca (export: phosphorites, ores, citrus fruits, cork, food, import: equipment, fabrics, oil products), Dakar (peanut, dates, cotton, livestock, fish, ores , import: equipment, oil products, food), Cape Town, Buenos Aires (export: wool, meat, grain, leather, vegetable oil, linseed, cotton, import: equipment, iron ore, coal, oil, manufactured goods), Santos , Rio de Janeiro (export: iron ore, pig iron, coffee, cotton, sugar, cocoa beans, lumber, meat, wool, leather, import: petroleum products, equipment, coal, grain, cement, food), Houston (oil , grain, sulfur, equipment), New Orleans (ores, coal, building materials, automobiles, grain, rolled metal, equipment, coffee, fruit, food), Savannah, New York (general cargo, oil, chemical cargo, equipment, pulp , paper, coffee, sugar, metals), Montreal (grain, oil, cement, coal, timber, metals, paper, asbestos tons, weapons, fish, wheat, equipment, cotton, wool).

Air traffic plays a leading role in passenger traffic between Europe and North America across the Atlantic Ocean. Most of the transatlantic lines run in the North Atlantic through Iceland and Newfoundland. Another message goes through Lisbon, Azores and Bermuda. The air route from Europe to South America passes through Lisbon, Dakar and further through the narrowest part of the Atlantic Ocean in Rio de Janeiro. Airlines from the US to Africa pass through the Bahamas, Dakar and Robertsport. On the coast of the Atlantic Ocean there are spaceports: Cape Canaveral (USA), Kourou (French Guiana), Alcantara (Brazil).

Minerals

Mining, primarily oil and gas, is carried out on the continental shelves. Oil is produced on the shelves of the Gulf of Mexico, the Caribbean Sea, the North Sea, the Bay of Biscay, the Mediterranean Sea, and the Gulf of Guinea. There is also natural gas production on the shelf of the North Sea. Sulfur is commercially mined in the Gulf of Mexico, and iron ore off the island of Newfoundland. Diamonds are mined from sea placers on the continental shelf of South Africa. The next most important group of mineral resources is formed by coastal deposits of titanium, zirconium, tin, phosphorites, monazite and amber. Coal, barite, sand, pebbles and limestone are also mined from the seabed.

Tidal power plants have been built on the shores of the seas of the Atlantic Ocean: "La Rance" on the Rance River in France, "Annapolis" in the Bay of Fundy in Canada, "Hammerfest" in Norway.

Recreational resources

The recreational resources of the Atlantic Ocean are characterized by considerable diversity. The main countries of formation of outbound tourism in this region are formed in Europe (Germany, Great Britain, France, Italy, the Netherlands, Belgium, Austria, Sweden, the Russian Federation, Switzerland and Spain), North (USA and Canada) and South America. The main recreational areas: the Mediterranean coast of Southern Europe and North Africa, the coasts of the Baltic and Black Seas, the Florida peninsula, the islands of Cuba, Haiti, the Bahamas, areas of cities and urban agglomerations of the Atlantic coast of North and South America.

Recently, the popularity of such Mediterranean countries as Turkey, Croatia, Egypt, Tunisia and Morocco has been growing. Among the countries of the Atlantic Ocean with the largest flow of tourists (according to 2010 data from the World Tourism Organization) stand out: France (77 million visits per year), USA (60 million), Spain (53 million), Italy (44 million), Great Britain (28 million), Turkey (27 million), Mexico (22 million), Ukraine (21 million), Russian Federation (20 million), Canada (16 million), Greece (15 million), Egypt (14 million), Poland (12 million ), Netherlands (11 million), Morocco (9 million), Denmark (9 million), South Africa (8 million), Syria (8 million), Tunisia (7 million), Belgium (7 million), Portugal (7 million) , Bulgaria (6 million), Argentina (5 million), Brazil (5 million).

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The vast water spaces of the planet, covering most of it and the surrounding islands and continents, are called oceans. Among them, the largest are the Atlantic and the Pacific. These are two giants that people know far from everything about. Mankind knows where the Atlantic Ocean is located, what are its boundaries, underwater inhabitants, relief, etc.

Atlantic Ocean

The Atlantic Ocean is considered the second largest after the Pacific. However, it is better studied and mastered, in comparison with other water areas. And where is the Atlantic Ocean, what are its boundaries? This giant is located along the length of the entire planet: in the east, the borders are North and South America, in the west - Europe, Africa. In the south, the Atlantic waters pass into the Southern Ocean. In the north, the giant is bounded by Greenland.

In those places where the Atlantic Ocean is located, there are practically no islands, which distinguishes this water area from others. Another distinguishing feature is the complex bottom topography and broken coastline.

Atlantic Ocean parameters

If we talk about the area, then 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. In the place where the Puerto Rico Trench is located, the depth exceeds eight kilometers.

There are two parts in the Atlantic Ocean: northern and southern. The conditional border between them runs along the territory of the equator.

Bays, seas and currents

The area of the seas and bays accounts for about sixteen percent of the total ocean area: about fifteen million square kilometers, with a volume of thirty million cubic kilometers. The most famous seas of the Atlantic 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 not far from the Arctic Circle, at 65°40"N (northern point), and in the south the sea is defined by a boundary at 53°45"N. sh., located near Wismar. In the west, the border is located near Flensburg, in the east - in the region of St. Petersburg.

Many are interested in the question: "Where is the North Atlantic Current 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 particular 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 of ocean water. Thanks to them, the west is warmer than the east. This feature is associated with the course of the Gulf Stream and its branches - Antilles, Brazilian, 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 northeast extension of the Gulf Stream. It starts at the Great Newfoundland Beam. West of Ireland, the current is divided into two parts, one of which is the Canary.

Northern part of the ocean

The northern border of the Atlantic has a rugged coastline. A small part has a connection with the Arctic Ocean: it communicates with it through several narrow straits. In the northeast is Davis Strait, which connects the Baffin Sea with the ocean. Closer to the center of the northern border is the Denmark Strait, and between Norway and Iceland, the border is the Norwegian Sea.

In the southwest of the North Atlantic Ocean is the Gulf of Mexico, which communicates with the Gulf of Florida. Also in this part is the Caribbean Sea. And besides, there are many other well-known bays: Hudson, Barnegat, etc. The largest islands are located in this part of the basin: Cuba, Haiti, and the British Isles. There are also island groups closer to the east, but they are small. Among them, the most popular are the Canaries, Azores, Cape Verde. To the west are the Bahamas.

Southern part of the water area

The southern borders of the ocean are not as strongly indented as in the northern part. There are no seas here, but there is a very large gulf - 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. Examples are the Ascension Islands and Saint Helena.

There are also currents in the south, but here the waters move counterclockwise. The most powerful and largest current of this part is the South Tradewind, which branches off the coast of Brazil. One of its branches goes to the shores of South America, and the second one connects with the Atlantic current and moves to the 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.

INTRODUCTION

Introduction chapters:

Seas washing the territory of Russia
- Seas of the Atlantic Ocean
From the history of the geographical study of the territory of Russia
- The initial period of scientific research on the territory of Russia
- The period of major expeditionary research, including branch research
- Soviet period of branch and complex research

Seas of the Atlantic Ocean

The three inland seas of the Atlantic Ocean - the Baltic, Black and Azov - wash small areas of Russian territory. All of them protrude deeply into the mainland, and their connection with the ocean is through other seas and shallow straits. A weak connection with the ocean determines their rather peculiar hydrological regime. The western transfer of air masses has a decisive influence on the climate of the seas.

Table 1. Seas washing the territory of Russia

The ancient Slavs called the Baltic Sea Varangian. This is the westernmost of the seas washing the shores of Russia. It is connected to the ocean through the shallow Danish Straits and the North Sea. The Baltic Sea was formed in the Quaternary in a tectonic trough that arose at the junction of the Baltic Shield with the Russian Plate. During periods of glaciation, its basin was covered by continental ice. In the Holocene, the sea went through several lacustrine and marine stages in its development and, apparently, at a certain period of time connected with the White Sea.

The depths of the Baltic Sea are shallow. The maximum depth is south of Stockholm (470 m). In the Gulf of Finland near the coast of Russia, the depth is less than 50 m, near the Kaliningrad coast - somewhat more.

The main features of the climate of the Baltic Sea are formed under the influence of a steady transfer of temperate air from the Atlantic. Cyclones often pass through the sea, accompanied by western, southwestern and northwestern winds, cloudy weather and heavy rainfall. Their annual number reaches 800 mm and more. In summer, cyclones carry moist cool air, so the average temperature in July is 16-18°C, and the water temperature is 15-17°C. In winter, the Atlantic air causes thaws, since its average temperature in January is about 0°C. The sometimes cold arctic air breaking through here can lower the temperature to -30...-35°C. The Gulf of Finland, located near the borders of Russia, is covered with ice in winter; off the coast of the Kaliningrad region, there are only floating ice. However, in exceptionally severe winters, the entire sea froze (1710, 1809, 1923, 1941, 1955, etc.).

About 250 rivers flow into the Baltic Sea, but about 20% of the annual river runoff is brought into the sea by the river. Neva (79.8 km 2). Its flow exceeds the flow of the three other largest rivers: the Vistula, the Neman and the Daugava, combined. The flow of the Neva is regulated by lakes, so it is characterized by one spring-summer maximum. Strong prolonged westerly winds raise the water level in the eastern part of the Gulf of Finland, which caused catastrophic floods in St. Petersburg, located at the mouth of the Neva (1824, 1924). Limited water exchange with the ocean and significant river runoff determine the low salinity of sea water (2-14‰, off the coast of Russia - 2-8‰).

The fauna of the Baltic Sea is depleted in species due to high desalinization, low mixing of waters and the poverty of plankton. The following fish are of commercial importance: herring, Baltic sprat, cod, whitefish, chime, lamprey, smelt, salmon. The seal lives in the sea, the number of which is declining due to the pollution of sea waters.

The Black Sea is the warmest among the seas washing the shores of our Motherland. In ancient Greece it was called Pontus Euxine which means "hospitable sea". In terms of area, it is almost equal to the Baltic, but differs sharply in volume and depth (see Table 1). The connection of the Black Sea with the ocean is carried out through a system of inland seas (Marmara, Aegean, Mediterranean) and straits (Bosporus, Dardanelles, Gibraltar). The greatest length of the Black Sea water area from west to east reaches 1130 km, the maximum width (from north to south) is 611 km, the minimum is only 263 km.

The Black Sea lies in a deep tectonic basin with oceanic-type crust and Cenozoic sedimentary cover. The maximum depth of the sea reaches 2210 m. The depression is delineated by the continental slope, which in a number of places (especially near the Caucasian coast) is strongly dissected by underwater canyons. The shelf is most developed in the northwestern part of the sea, off the coast of Ukraine. The coastline of the sea is poorly dissected.

The geographical position of the sea and the relatively small area of the water surface determine the same type of climate throughout its water area, close to the Mediterranean, with warm, wet winters and relatively dry summers. However, the orography of the coastal territories causes some differences in the climate of individual sections of the sea, in particular, an increase in precipitation over the eastern part due to the influence of the mountainous barrier of the Caucasus.

In winter, the synoptic situation determines the predominance of northeast winds with an average speed of 7-8 m/s over almost the entire sea area. The development of strong (more than 10 m/s) and especially storm winds is associated with the passage of cyclones over the sea. The average air temperature in winter decreases from the open sea to the coast. In the north-eastern part, near the coast of Russia, it approaches 0 ° С, in the north-west it is -2 "С, and in the south-east + 4 ... + 5 ° С.

In summer, northwest winds prevail over the sea. Their average speed is 3-5 m/s, decreasing from west to east. Strong, especially stormy, winds are rare in summer and are also associated with the passage of cyclones. The average air temperature in August varies from + 22°C in the northwest to 24-25°C in the east of the sea.

Numerous rivers flowing into the Black Sea annually bring 346 km 2 of fresh water into it. The Danube gives the largest runoff (201 km 2 / year). All rivers of the northwestern part discharge 270 km 2 /year of fresh water into the sea, i.e. almost 80% of the total runoff, while the rivers of the Caucasian coast bring only 43 km2. The largest runoff occurs in the spring, the smallest is observed in the fall.

On the surface of the sea along the coast there is a cyclonic current. In the central part of the sea, two rings of cyclonic currents are traced: one - in the western part, the other - in the eastern part of the sea. Along the Russian shores, the current carries water from the south. Through the straits there is an exchange of water with neighboring seas. Through the Bosphorus, the surface current carries the Black Sea water, and the deep current delivers more salty and heavier water from the Sea of Marmara to the Black Sea. The salinity of the Black Sea waters in the central part is 17-18‰, and increases with depth to 22.5‰. Near the mouths of large rivers, it drops to 5-10‰.

The Black Sea is very peculiar in terms of the distribution of dissolved gases in the water column. It is saturated with oxygen and therefore only the upper layer is favorable for life here to depths of 170-180 m. Below, oxygen is quickly replaced by poisonous hydrogen sulfide, which is widespread throughout the entire water column from the lower boundary of the oxygen layer to the bottom, therefore the deep layers of the Black Sea are devoid of life.

There are 166 species of fish in the sea. Among them there are Pontic relics (beluga, stellate sturgeon, sturgeon, herring), Mediterranean forms (mullet, mackerel, horse mackerel, red mullet, sprat, anchovy, tuna, stingray, etc.) and freshwater forms (ram, pike perch, bream). Of the mammals in the Black Sea, endemic species have survived - the Black Sea bottlenose dolphin (dolphin) and the white-bellied seal, or the monk seal, listed in the Red Books.

The Sea of Azov is the smallest and shallowest on the planet. Its area is 39.1 thousand km 2, the volume of water is 290 km 2, the greatest depth is 13 m, the average is about 7.4 m. The narrow and shallow Kerch Strait connects it with the Black Sea. The Sea of Azov is a shelf. The relief of its bottom is quite simple: the shallow coast turns into a flat and flat bottom. Depths slowly and smoothly increase with distance from the coast.

The sea is deeply incised into the land, its water area and volume of water are small and do not have a significant impact on the climate; therefore, its climate is characterized by continental features, more pronounced in the northern part of the sea, which is characterized by cold winters and hot, dry summers. In the southern regions, which are more influenced by the proximity of the Black Sea, the climate is milder and more humid. The average temperature in January is -2...-5°C, but with storm winds from the east and northeast directions, temperatures may drop to -25...-27°C. In summer, the air over the sea warms up to 23-25°C.

Two large rivers - Don and Kuban - and about 20 small rivers flow into the Sea of Azov. The Don and Kuban bring over 90% of the annual river water runoff into the sea, so almost all fresh water flows into the eastern part of the sea. The vast majority of runoff falls on the spring-summer period. Water exchange with the Black Sea takes place through the Kerch Strait. About 49 km 2 of water per year flows out of the Sea of Azov, and about 34 km 2 enters the Black Sea water, i.e. outflow to the Black Sea prevails. The salinity of sea waters in the Sea of Azov in the first half of the century was about 11‰. Then, due to a reduction in the inflow of river waters used for irrigation and an increase in the inflow of Black Sea waters, salinity began to increase and by the beginning of the 1980s it reached 13.8‰.

The shallow Sea of Azov warms up well in summer. In July-August, the average sea water temperature is 24-25°C. Maximum warming (up to 32°C) occurs near the shores. In the open sea, the temperature does not exceed 28-28.5°C. The long-term average annual water temperature on the sea surface is 11°С.

Ice forms on the Sea of Azov every year, but due to frequent and rapid changes in weather conditions, ice can repeatedly appear and disappear during the winter, turning from immobile to drifting and vice versa. Ice formation begins at the end of November in the Taganrog Bay. The final cleansing of the sea from ice occurs in March - April.

ADRIATIC SEA

SEA OF AZOV

BALTIC SEA

IONIAN SEA

IRISH SEA

CARIBBEAN SEA

SEA OF MARBLE

SARGASSO SEA

NORTH SEA

SEA SCOSH (SCOTIA)

MEDITERRANEAN SEA

TYRRHENIAN SEA

SEA WEDDELL

BLACK SEA

AEGEAN SEA

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

Characteristics of the Atlantic Ocean

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

Atlantic Ocean from the north side

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

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

South Atlantic Ocean

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

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

Landmarks of the Atlantic Ocean

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

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

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

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