As you move away from the subtropical zones, both towards the equator and towards the pole, salinity decreases. In the North Atlantic, north of the trade wind regions, the distribution of salinity is directly dependent on the current system. In the area of the Gulf Stream and the North Atlantic Current, salinity changes quite slightly and remains within the range of 34-35‰.
In a given water area, precipitation prevails over evaporation, and therefore the water salinity is quite close to the ocean average. It is approximately 35‰. This is due to the passage of the salty North Atlantic Current through the water area.
Annual fluctuations in water salinity are small. The greatest vertical changes in salinity occur to a certain depth (“troposphere” by Defent), different for different regions of the ocean, and below this depth they amount to hundredths of a ppm. The nature of the change in salinity with depth is different: at lower latitudes, salinity decreases with depth, and at higher latitudes it increases or changes little. As an example, the given measurement data of water salinity with depth for representative points of the water area (Table 4 and Fig. 8) / 6 /
The distribution of water salinity on the ocean surface is largely determined by the current system. In general, many features noted in the temperature distribution can be traced here. The predominant maximum value of 35.5‰ is observed in the center of the water area, although higher values are also observed in the south off the coast of Spain (values close to 36‰). To the north of these areas, salinity decreases. This decrease is especially noticeable in the North Sea.
The salinity of water on its surface in the open sea reaches 35‰, near the coast it drops to 32‰, and in summer period even up to 30‰, but in the northern part of the sea it rises to 35.25‰.
The reason for such low salinity lies in the large supply of fresh water from rivers such as the Elbe and Weser, as well as the supply of desalinated water from the Baltic Sea through the Danish Straits.
As the analysis of maps 154-167 /1/, table shows. 4 and fig. 9, in the surface layer of this area it is located almost uniformly throughout the year (34.8‰). Only in the North Sea, especially in August, a deviation of up to 32.42‰ is observed. In the upper part of the active layer, the water salinity decreases slightly and becomes almost uniform throughout the year (approximately 34.50‰). The thickness of this homogeneous layer is 25 m. Somewhat deeper - up to 50 m - the water salinity increases sharply and reaches 35‰. In the subsurface layer, salinity increases rapidly with depth and at a horizon of 100 m reaches a maximum of 35.5‰ (open part of the ocean and in the North Sea in August) and 34.75‰ (in February in the North Sea).
Table No. 4
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Vertical distribution of salinity for representative points in extreme months. ‰ (monthly averages) |
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Depth, m |
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Open part of the water area |
North Sea |
Open part of the water area |
North Sea |
|
|
34.75 (northern outskirts) |
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In the intermediate structural zone, the main halocline is clearly expressed, and the salinity decreases most strongly in the layer from 100 to 200 m and at the 200 m horizon the salinity is already 35.25‰.
Among all the oceans of our planet, the Atlantic Ocean has occupied and continues to occupy the most important place in world shipping and international trade. This happened historically. Since ancient times, the Atlantic Ocean began to be developed by man. Back in the 2nd millennium BC. e. In its central regions, coastal navigation, fishing, and harvesting fruits of the sea were developed. In order to meet the needs of navigation and fishing, oceanological observations have been carried out here since ancient times.
Many reasons contributed to the development of the Atlantic Ocean, but two played the main role. On the one hand, there were favorable natural conditions that facilitated navigation in many of its regions. And on the other hand, the relatively rapid pace of socio-economic development of Western European countries, which, starting from the era of the Great Geographical Discoveries (XV-XVI centuries), took the path of colonial conquest and turned the Atlantic Ocean into an arena of complex economic and social processes.
As part of the World Ocean, the Atlantic Ocean is limited by the shores of America in the west, Europe and Africa in the east. In the north, it is separated from the Arctic Ocean by a conventional line running along the eastern entrance to the Hudson Strait, through the Davis and Denmark Straits and further from Cape Gerpir (Iceland) through the island of Fug-le (Faroe Islands) and Muckle Flagg (Shetland Islands) to Statland Peninsula (Norway). In the south, the border with the Pacific Ocean runs along the Drake Passage from Fire Island to the Antarctic Peninsula, and with the Indian Ocean - from the Cape of Good Hope in southern Africa along the meridian 20° east. to the shores of Antarctica. Within these limits, the area of the Atlantic Ocean is 91.7 million km 2 - this is the second largest ocean on our planet. Its configuration is characterized by a large (about 8 thousand miles) meridional extent, an S-shape, due to which it is quite wide in temperate and partly in high latitudes and narrow near the equator, between the coasts of South America and Africa. The coastline of the Atlantic Ocean is strongly dissected in the northern hemisphere and rather weakly indented in the southern hemisphere. Some large seas it forms off the coast of America. Its Mediterranean seas extend far into the European continent: the North, Baltic, Mediterranean, Black, Azov.
The floor of the Atlantic Ocean is largely dissected. About 7% of its area is occupied by shelves. They are extensive in the northwest, off Newfoundland, Nova Scotia, Western Greenland, in the Georges Bank area, and quite significant in the Gulf of Mexico and the Caribbean Sea, off the coasts of Argentina and Uruguay. In the northeast, the shelf is developed off the coast of Great Britain, France, and West Africa. In the central part of the Atlantic Ocean, the Mid-Atlantic Ridge with longitudinal rift valleys, transverse faults and depressions extends in a wide meridionally elongated chain. On both sides of it lie deep basins with a relatively flat bottom. The greatest depths of the ocean are to the west of this ridge. There are many relatively small underwater banks in the Atlantic Ocean.
Due to the large meridional extent of the ocean, all natural zones are found in it - from the northern subpolar to the southern polar, which determines a wide variety of its climatic conditions. However, the predominant part of the ocean area is between 40°N. and 42° S is located in subtropical, tropical and equatorial climate zones. The most severe areas are the Far South and, to a lesser extent, areas near its northern borders.
The Atlantic Ocean is characterized by a significant influx of river water, fairly evenly distributed across latitude: in the west the rivers flow into the ocean: St. Lawrence, Mississippi, Amazon, La Plata, in the east there are rivers of the Baltic and North Sea basins, Niger, Congo, etc.
The hydrological conditions of the Atlantic Ocean are complex and varied. The average on the surface is 16’53°, which is significantly lower than in the Pacific and Indian oceans. This is explained by the relatively small radiation heating of the surface of the Atlantic Ocean and the cooling effect of water and ice carried out from the Arctic Ocean and coming from the Antarctic region. The average salinity at the surface of the Atlantic Ocean is 35.3% 0, which is close to the average for the whole.
The general circulation of water in the Atlantic Ocean manifests itself in the form of horizontal and vertical movements. Horizontal movements of water are associated with oceanic gyres that are stable in time and large-scale in area. Their periphery is usually occupied by the main ocean currents - the Gulf Stream, North Atlantic, Canary, Northern and Southern trade winds, Brazilian, Bengal and Antarctic.
On the northern edge of the ocean, the East and West Greenland Currents, the Labrador Current, the North Atlantic Current and the Irminger Current form the Subarctic (subpolar) cyclonic water cycle. Most of the space of the North Atlantic is occupied by the Northern Subtropical Gyre, in which the anticyclonic circulation on the surface changes to cyclonic, starting from depths of 400-500 m.
The Northern Trade Wind Current and the Northern Equatorial Countercurrent form the Northern Tropical Cyclonic Gyre. The Northern Tropical Anticyclonic Gyre is observed between it and the equator. It is formed by the North Equatorial and Guinea Currents in the north and the South Trade Wind and Guiana Currents in the south.
To the south of the equator, similar oceanic gyres can be traced: Southern tropical cyclonic, Southern subtropical anticyclonic (unlike its northern antipode, it does not change the direction of water movement with depth), Southern subantarctic cyclonic.
In recent years, non-stationary eddies with horizontal dimensions of 100-200 km have been discovered in the North Atlantic Ocean. These formations are the subject of comprehensive research. Vertical water movements are well developed throughout the Atlantic Ocean. At the same time, in the upper and bottom layers, water rises predominate, and in the intermediate and deep layers, water declines predominate. Water rises in areas of divergence of large ocean currents and off the coast of West-Central Africa, where upwelling is well expressed, are of important biological significance.
These physical and geographical features represent the main natural prerequisites for the development of economic activity in the Atlantic Ocean. However, socio-economic factors influence it no less significantly. They are well reflected by the economic-geographical location (EGP) of the Atlantic Ocean.
In relation to its hinterland, it is characterized by several important features. The shores of three continents, where more than 70 coastal states with general population more than 13 billion people. This is a significant part of the population of our planet. The states of the Atlantic Ocean basin include socialist, developed capitalist and developing countries.
The countries surrounding the Atlantic Ocean have rich natural resources, which they exploit to a greater or lesser extent. The centers of raw material extraction are located relatively evenly, and the main processing areas are concentrated mainly in the states of the North Atlantic Ocean. This is another characteristic feature of the Atlantic Ocean EGP.
The coasts of America, Europe and Africa largely separate the waters of the Atlantic Ocean from other oceans.
The Atlantic's natural connections with other oceans lie in the subpolar regions. In the central part, the Atlantic Ocean is connected by the Panama Canal to the Pacific and through the Mediterranean Sea by the Suez Canal to the Red Sea and the Indian Ocean. Thus, the Atlantic and its neighboring oceans converge over large areas in the subpolar regions and are connected to a limited extent in the central Atlantic. The Panama and Suez Canals reduce distances, but they, as already noted, have limited throughput, since their depths do not allow modern large-capacity vessels to pass through. Transportation in the northern and southern parts of the Atlantic Ocean is not limited.
In general, the Atlantic Ocean is conveniently located in relation to other oceans, with which it has good connections. Therefore, the Atlantic is also characterized by great opportunities for transport connections with neighboring oceans.
By virtue of natural conditions and EGP The Atlantic Ocean occupies a central place in the World Ocean, especially considering its relatively small latitudinal extent and the fact that many economically developed countries have access to it.
In the Atlantic Ocean, the zonality of a number of hydrological characteristics (primarily water temperature, salinity) is clearly manifested. In oceanology, it is customary to zonate the ocean surface into zones (belts), and the dependence of the diversity of species and abundance of the organic world on the thermal state of the waters is clearly visible.
Natural zones, according to D.V. Bogdanov, cover a layer several hundred meters deep, taking into account the characteristics of temperature distribution, water salinity, the uniqueness of currents, hydrochemical, geological-tectonic and biological properties. Natural zones have their own climatic, ice and other conditions. In the Atlantic Ocean, 10 belts (zones) were identified - the equatorial and 8 (almost symmetrical) in each hemisphere: tropical, subtropical, temperate, subpolar, and in the Southern Hemisphere there is also a polar (Antarctic) belt. In the middle parts of the ocean, the influence of continents on climate and water conditions is insignificant; processes are developed and conditions characteristic of the entire belt are preserved. In the coastal parts, different conditions are created. Therefore, within the zones, areas are distinguished whose nature, due to relatively shallow depths, the presence of a large influx of river water, the presence of islands, and wind systems, has specific individual features. Some of them, which have the most striking natural features, have been characterized.
Characterized by low water temperatures throughout the year, the presence of ice in winter, increased salinity in winter and desalination in summer. The waters have a cyclonic circulation and high biological productivity. There are 3 regions: Labrador, characterized by the constant interaction of warm and cold waters, dense fogs in transition seasons, and the presence of icebergs; the Denmark Strait, in which water exchange with the Arctic is clearly expressed and the removal of Arctic ice is constant; The Davis Strait is also characterized by constant water exchange between the Arctic region and the Atlantic.
A water area over which intense interaction, mixing and transformation of air masses occur. The movement of both air and water masses generally occurs from west to east. Large pressure and temperature gradients are associated with the interaction of arctic, mid-latitude and tropical air masses. In the west of the belt, cold and warm currents converge; here the belt is narrow, and in the east it is wide. The belt is characterized by the predominance of cyclonic weather patterns, frequency of storm winds, increased cloudiness, large amounts of precipitation. The warm North Atlantic Current is the main current of the belt. The current “branches” into a number of smaller currents, there are countercurrents and eddies. The North Atlantic Current region is the most important fishing region. The main fish resources are concentrated on the shelf off the coast of North America, consisting of several banks - Jordes, Brown, Sable, Great Newfoundland, Flemish Cap. High productivity is explained by the diversity of depths and soils, dynamic waters, and good oxygen supply. The main environmental problem of the belt is significant water pollution with oil products and runoff from the shores where large urban agglomerations are located - New York, Boston, Philadelphia, etc.
Among the regions, the Baltic Sea stands out - a relatively shallow closed body of water experiencing intense anthropogenic impact.
It is located between 25° and 40° N. w. In summer, the North Atlantic High dominates over the water area, which determines fairly stable dry weather, little cloudiness, and low relative humidity. The surface of the water receives a large amount of solar radiation. The belt is characterized by blue sky, blue sea, and weak waves. There are almost no currents in the middle part of the belt. On the flanks, on the contrary, there are many currents: the North Trade Wind, Gulf Stream, North Atlantic and Canary, which form the northern subtropical circulation, resulting in the formation of a vast region of convergence of waters. In winter, temperate cyclones dominate over the subtropical zone, causing cloudy, rainy weather.
The biological productivity of the belt is low. It is sometimes even called an “ocean desert” with very clear, bright blue water. The central part of the belt has two distinctive regions - the Sargasso Sea and the Gulf Stream.
The Sargasso Sea is located between 40° and 66° west. d. This is an area of convergence of waters, weak currents, high evaporation, which is twice the amount of precipitation (2000 and 1000 mm per year, respectively). The deficit is compensated by the surrounding waters. Water salinity is 37.5% or more. The surface layer of water heats up to 26°C. The water is very transparent. The origin of the name is interesting. In Portuguese sargasso means " grape brush" This is the name given to algae that float freely in sea water. They have “leaves” and “berries”, somewhat reminiscent of grapes. In the Sargasso Sea, according to some estimates, there are 4-11 million tons. The Sargasso Sea is, in a sense, an oasis of almost motionless water, limited by powerful currents. Here you can find everything that enters the North Atlantic from land and from passing ships. The level of the Sargasso Sea is 1-2 m higher than the parts of the ocean from the east and south, which indicates a surge of water by currents. The peculiarity of the waters of this region is that they are warmer than the surrounding waters. Even at a depth of 1000 m, their temperature is 10°C, while in neighboring areas it is 5°C. Sea waters have very low productivity: they have few nutrients, and therefore no plankton.
The Gulf Stream region is no less interesting. Its most important difference is the presence of a powerful warm current. The main process is the transfer of tropical waters to higher latitudes. On both sides of the Gulf Stream there are countercurrents: the eastern one is the flow of warm waters to the southwest, the western one is of relatively cold waters over the shelf.
The region of the Mediterranean Sea, an intercontinental inland basin with unique natural features, is the most developed. It's peculiar. mini-ocean - a relic of Tethys, a rift zone in the “old age” stage. Within its boundaries there are depressions with suboceanic crust and areas of submerged parts of continents. The sea has its own system of currents, special properties of waters and the organic world. Traditionally, seas are separated by peninsulas and islands (Tyrrhenian, Adriatic, Ionian, Aegean and the smallest on Earth - Marmara, which connects the Mediterranean with the Black Sea). The Mediterranean Sea has long been developed by people and is used intensively and variedly. This indoor pool has the sharpest environmental problems, which are difficult to resolve.
This belt is located between 10-12° and 25° N. w. It includes the Caribbean Sea and a large part of the Gulf of Mexico. The main characteristic is the dominance of the trade winds.
The belt is characterized by dry and warm winters and wetter summers. From west to east, the thickness of the heated water layer changes quite sharply, which is associated with compensatory flows of colder waters. The salinity of the water varies from 36.5%o in the north to 35%o closer to the equator. Storms over the ocean are rare. In autumn, cyclones arise over tropical latitudes, carrying them to the continents. strong winds and showers. There are coral buildings in this belt; here are ideal conditions for their existence:
warm water, clean, clear and relatively salty. In the tropical zone, the fauna is rich in species composition: flying fish, tuna, golden mackerel, barracuda, surgeon fish and others. The eastern waters of the tropical zone off the coast of West Africa differ significantly from the central and western ones. The main process here is the rise of cold waters (14-18°C), which causes an improvement in oxygen supply and intensive bioproduction. Large concentrations of planktivorous and predatory fish - sardinella, hake, horse mackerel, mackerel, small tuna, and sharks - form here. Invertebrates include shrimp, lobsters, squid, and cuttlefish. Regions of the tropical belt (West African, Caribbean, Gulf of Mexico, Bahamas) are closely connected with the continents.
It is located on both sides of the equator: 10-12° N. w. and 0-3° S. w. The main process is intense heat and moisture exchange between the ocean and. Twice a year, a zone of convergence of air masses with heavy rain passes through the belt.
In general, rainfall ranges from 2000 to 4000 mm per year. Water temperature 26-29°C, salinity 35% o. In areas of large river flow at the mouths of the Amazon, Orinoco and other rivers, salinity drops to 32% o. Biological productivity is average between the subtropical and tropical zones. There are 2 areas: Western Shelf and Gulf of Guinea.
Southern tropical zone
It is located between 0-3° and 18° S. w. According to the main processes, it is analogous to the northern tropical one. It is characterized by southeast trade winds.
The Southern Trade Wind Current, arising from the Benguela and, to a lesser extent, Guinea Current, bifurcates into the Brazilian and Guiana currents off the coast of South America. These currents are less powerful than the Gulf Stream. The water temperature on the surface is 25-27°, salinity is 34-36% o. One area with special conditions is identified at the mouth of the river. Congo.
Analogous to the northern subtropical. In the open ocean there is the same intense solar radiation, low precipitation, high evaporation, and very weak winds of variable directions.
The waters here are warm (up to 18°C) with high salinity (37% o). The waters of the warm Brazilian Current deviate to the left, moving away from the shore, and spread out like a fan. In the east, off the coast of Africa, the cold Benguela Current is formed with a temperature of 10-12°C. This area is characterized by increased bioproductivity, especially from Whale Bay to the mouth of the river. Kune no. In the subtropical zone there are three regions: La Plata, Benguela and South-West Africa.
This belt has different features than the temperate zone of the Northern Hemisphere. It is largely influenced by the Pacific Ocean and nearby Antarctica.
The boundaries of the belt run almost parallel. Within its boundaries, the waters are already included in a single ring around Antarctica with branches along the coasts of South America (Falklands Current) and Africa (Benguela Current). The cold Falkland Current in the La Plata area meets the Brazilian Current, therefore there is high biological productivity on the Uruguay shelf and off the coast. There are bays of San Jorge and San Matias, deep and convenient for sea vessels. In the 40-50's latitudes of the South Atlantic, westerly and north-westerly winds predominate; a series of cyclones move from west to east, accompanied by strong storm winds - the famous “roaring forties” latitudes. The strength and frequency of storms are high throughout the year, but storms are especially strong in the fall: wave heights can reach 20 m. Cape Horn is known as the stormiest place on Earth. Layered fog prevails, fog and prolonged drizzle are frequent. Air temperatures are positive throughout the year (0-10°C), waters are characterized by low salinity (up to 34% o). The presence of latitudinal currents prevents the migration of fish in the meridional direction. There is one region with special conditions - Patagonian (in the west of the belt).
Its waters are characterized by a special regime and unique flora and fauna. The border is drawn along the average position of the front separating the temperate and Antarctic latitudes. The atmospheric front largely determines the ocean regime. Here the convergence of Antarctic cold and warmer waters of temperate latitudes occurs.
The convergence zone in the South Atlantic runs along 48-50° S. w. The average depth is 3.5 km. Within the shelf zone, the water temperature is lower due to intense heat transfer to the atmosphere; they are classified into a unique type - shelf Antarctic waters. They have a high oxygen content as they interact with the atmosphere. Characteristic feature region is the constant presence of ice. The thickness of first-year ice is 1.5-2 m, the thickness of fast ice is up to 10 m. Shelf ice is a continuation of continental ice, its average thickness is 430 m, and in the sea it decreases to 150-250 m. Icebergs traveling in the ocean constantly break off into the ocean up to 10 years.
The richness of the ocean's fauna especially contrasts with the poverty of the organic world.
Invertebrates are represented by crustaceans (krill), giant jellyfish. Mammals include pinnipeds (Weddell seals, crabeater, leopard seal, sea lion). This region is also known for the largest mammals on Earth - whales: baleen and toothed. Baleen whales are the fin whale, humpback whale, sei whale and the blue whale, or vomit whale, reaching a length of 33 m. Toothed whales include the sperm whale, killer whale and bottlenose whale.
The Scotia Sea (Scotia) and the Patagonian region stand out.
The water area washing the shores of Antarctica. A significant part of it belongs to the Weddell Sea. Cold waters are essentially permanently covered with ice.
The Ronne and Larsen ice shelves reach out to the ocean waters. Throughout the year, a huge amount of ice is carried into the ocean, which cools and desalinates the water. Sea ice forms in autumn and winter. Cold water sinks along the continental slope and has a temperature of -1°C. It reaches far to the north.
The biological productivity of the waters is relatively high, plankton is abundant, and there is krill. The fauna is similar to the subantarctic. IN sea waters penguins nesting on the Antarctic coast and islands feed.
It is worth starting with an interpretation of such a concept as the “world ocean” - this is the water surface of the entire Earth, surrounded by land (continents, islands, etc.). In Russia and in a number of European countries it is divided into four parts (oceans): Atlantic, Pacific, Indian, Arctic.
Many hundreds of millions of years ago, North and Africa, Antarctica and Europe were a continuous landmass. The last few million years were marked by such an event as the opening of the ocean basin, after which the land began to be divided into continents (this trend is still relevant today).
It bore various names: Atlantic, “the sea beyond the Pillars of Hercules,” Western Ocean, Sea of Darkness. At the beginning of the 16th century. Cartographer M. Waldseemuller called this ocean the Atlantic.
It is recognized as the second largest ocean on Earth after the Pacific. The ocean in question is located between Africa and Europe (in the east), Iceland and Greenland (in the north), South and North America (in the west), Antarctica and South America (in the south).
It has a strongly broken coastline with a pronounced division into separate regional water areas: bays and seas.
It is recognized that the salinity of the Atlantic Ocean in ppm, according to official data, is 35.4‰. Its greatest value is observed in This is due to strong evaporation and significant distance from the river drainage. The salinity of the Atlantic Ocean in some areas (at the bottom of the Red Sea) reached a value of 270 ‰ (almost saturated solution). A sharp desalination of ocean water was noted in the estuary areas (for example, at the mouth of the La Plata River - about 18-19 ‰).
The distribution of salinity in the ocean is not always zonal. It depends on the following reasons:
It occurs mainly at tropical latitudes (37.9‰). Area coordinates - 20-25° S. w. (South Atlantic), 20-30° N. w. (North Atlantic). In these places there is predominantly trade wind circulation, fairly little precipitation, evaporation in a layer of 3 m, and practically no fresh water flows here.
Slightly more salinity is observed in the Northern Hemisphere (in areas of temperate latitudes). All the waters of the current (North Atlantic) flow there.
It reaches a level of 35‰. The salinity of the waters (of the Atlantic Ocean) here changes as it deepens. This level is recorded at a depth of about 100-200 m. This is due to the surface Lomonosov current. It is known that the salinity of the surface layer in some cases is not identical to the salinity at depth. The previously indicated salinity indicator sharply decreases when colliding with the Gulf Stream and Labrador Current, the result of which is 31-32‰.
These are the so-called submarine springs - underground fresh water. One has long been well known to sailors. This source is located east of the peninsula called Florida (where sailors replenish supplies fresh water). It is a sandy area in the salty Atlantic Ocean with a length of up to 90 m. It hits at a depth of forty meters, then rushes to the surface. This is a kind of typical phenomenon - the unloading of a source in areas of karst development or within tectonic disturbances. In a situation where the pressure of groundwater significantly exceeds the pressure of the sea column, unloading will immediately begin - the process of outpouring of groundwater.
It is a well-known fact that water is an excellent solvent; therefore, there is no water in nature that does not contain soluble substances. Distilled water can only be obtained in a laboratory.
Salinity is the content of substances in grams dissolved in a liter (kg) of water. As mentioned earlier, the salinity of the Atlantic Ocean in ppm is 35.4‰. On average, 35 g of various substances are dissolved in 1 liter of ocean water. In percentage terms it is 3.5%. Thus, the percentage salinity of the Atlantic Ocean will also be approximately 3.5%. However, it is usually expressed in thousandths of a number (ppm).
Ocean water contains solutions of all known substances on Earth in varying proportions. The salinity of the Atlantic Ocean (like all other oceans) is the result of the fact that it contains significant quantities of table salt. Magnesium salts add bitterness to ocean water. It also contained silver, aluminum, gold, and copper. They make up a very small proportion; for example, 2 thousand tons of water contain a gram of gold. Obviously, there is simply no point in mining it.
Significant amounts of dissolved substances are difficult to detect due to their minute content. However, in total, this is already a huge amount (if all the ocean water could be evaporated, these substances would cover the bottom of the World Ocean with a layer of 60 m). From their total volume, it is even possible to create a shaft 1 km wide and 280 m high, encircling the Earth along the equator.
As has already become known, the first distinctive feature is the salinity of the Atlantic Ocean. In meters, its depth reaches 3700, and at the deepest point - 8742 m. Its area is 92 million square meters. km.
The seas of the Atlantic Ocean are: Mediterranean, Caribbean, Sargasso, Marmara, Aegean, Tyrrhenian, Northern, Baltic, Adriatic, Black, Weddell, Azov, Irish, Ionian.
Salinity of the Atlantic seas
Seas of the Atlantic Ocean | Sea salinity, (‰) |
1. Aegean | |
3. Weddell | |
4. Tyrrhenian | |
5. Mediterranean | |
6. North | |
7. Sargasso | |
8. Marble | |
9. Caribbean | |
10. Ionic | |
11. Baltic | |
12. Azovskoe | |
13. Irish | |
14. Adriatic |
There are at least four main ones. The salinity of the Atlantic Ocean (like any other body of water) depends on the following processes:
The high salinity is also associated with the influx of salt water from the Mediterranean Sea.
Previously, many sailors died of thirst in the ocean. Later, sailors began to stock up on a significant amount of fresh water, which took up too much space. Nowadays, water on ships is desalinated using special desalination plants.
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 is inland seas. The area of coastal seas is small and does not exceed 1% of total area water areas. 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 ocean waters is about 35 ‰. The Atlantic Ocean has a highly indented coastline with a pronounced division into regional waters: seas and bays.
The name comes from the name of the Titan Atlas (Atlas) in Greek mythology.
Characteristics:
The name of the ocean first appears in the 5th century BC. e. in the works 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 myth known in Ancient Greece about Atlas, the Titan holding the firmament on his shoulders at the westernmost 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, individual parts of the ocean were called the Western Ocean, the North Sea, and the Outer Sea. Since the middle of the 17th century, the only name referring to the entire water area was the Atlantic Ocean.
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 subarctic latitudes all the way to Antarctica. The border with the Indian Ocean runs along the meridian of Cape Agulhas (20° E) to the coast of Antarctica (Donning Maud Land). The border with the Pacific Ocean is drawn from Cape Horn along the meridian 68°04’W. or along the shortest distance from South America to the Antarctic Peninsula through the Drake Passage, from Oste Island to Cape Sterneck. The border with the Arctic Ocean runs along the eastern entrance of the Hudson Strait, then through Davis Strait and along the coast of Greenland to Cape Brewster, through the Denmark Strait to Cape Reydinupur 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 the northern border from 35° south. w. (based on the circulation of water and atmosphere) up to 60° south. w. (by the nature of the bottom topography) are classified as the Southern Ocean, which is not officially distinguished.
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, Azov Sea, 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 St. Lawrence, Labrador Sea. 
The largest islands and archipelagos of the Atlantic Ocean: British Isles (Great Britain, Ireland, Hebrides, Orkney, Shetland), Greater Antilles (Cuba, Haiti, Jamaica, Puerto Rico, Juventud), Newfoundland, Iceland, Tierra del Fuego archipelago (Terra del Fuego Land, Oste, Navarino), Maragio, Sicily, Sardinia, Lesser Antilles (Trinidad, Guadeloupe, Martinique, Curacao, Barbados, Grenada, St. Vincent, Tobago), Falkland Islands (Malvinas) (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), Zealand, Prince Edward, Balearic Islands (Mallorca), South Georgia, Long Island, Moonsund Archipelago (Saaremaa, Hiiumaa), Cape Verde Islands, Euboea, Southern Sporades (Rhodes), Gotland, Funen, Cyclades Islands, Azores, Ionian Islands, South Shetland Islands, Bioko, Bijagos Islands, Lesbos, Åland Islands, Faroe Islands, Öland, Lolland, South Orkney Islands, Sao Tome, Madeira Islands, Malta, Principe, Saint Helena, Ascension, Bermuda. 
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 present North Atlantic. The resulting rift zone was a western extension of the Tethys Ocean rift. The Atlantic Trench, at an early stage of its development, was formed as a connection of two large ocean basins: the Tethys Ocean in the east and the Pacific Ocean in the west. Further expansion of the Atlantic Ocean depression will occur due to the reduction in the size of the Pacific Ocean. In Early Jurassic times, 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, and the separation of North America from Europe began. At the same time, Greenland, moving to the north, broke away from Scandinavia and Canada. Over the past 40 million years and up to the present, the opening of the Atlantic Ocean basin has continued 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 African and South American plates continue to diverge at a rate of 2.9-4 cm per year. In the Central Atlantic, the African, South American and North American plates are diverging at a rate of 2.6-2.9 cm per year. In the North Atlantic, the spread 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 move to the west, the African plate to the northeast, and the Eurasian plate to the southeast, forming a compression belt in the Mediterranean Sea region. 
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 subject to continental glaciation, which formed relict glacial landforms. Another element of the relict relief of the shelf is flooded river valleys, found in almost all shelf areas of the Atlantic Ocean. Relict continental deposits are widespread. Off the coasts 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 formed sand ridges, which are the most widespread of modern subaquatic landforms. They are very characteristic of the shelf North Sea, 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 characterized by steep slopes, sometimes with a stepped profile, and are deeply dissected by submarine canyons. In some areas, the continental slopes are supplemented by marginal plateaus: Blake, Sao Paulo, Falkland on the American submarine margins; Podkupain and Goban on the underwater edge of Europe. The blocky structure is the Farrero-Icelandic Threshold, which extends from Iceland to the North Sea. In the same region is the Rokkol Rise, which is also a submerged part of the underwater part of the European subcontinent.
The continental foot, over most of its length, is an accumulation plain lying at a depth of 3-4 km and composed of a thick (several kilometers) layer of bottom sediments. Three rivers of the Atlantic Ocean are among the ten largest in the world - the Mississippi (solid flow 500 million tons per year), the Amazon (499 million tons) and the 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. In certain areas of the continental foot there are large fans of turbidity currents, among them the most significant fans of the underwater canyons of the Hudson, Amazon, and 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 in the southern direction, giant accumulative landforms are formed (for example, the “sedimentary ridges” of Newfoundland, Blake-Bahama and others).
Transition zones in the Atlantic Ocean are represented by the Caribbean, Mediterranean, and Scotia or South Sandwich Sea regions.
The Caribbean region includes: the Caribbean Sea, the deep-sea Gulf of Mexico, island arcs and deep-sea trenches. The following island arcs can be distinguished in it: Cuban, Cayman-Sierra Maestra, Jamaica-South Haiti, and the outer and inner arcs of the Lesser Antilles. In addition, the underwater rise of Nicaragua, the Beata and Aves ridges are distinguished here. The Cuban arc has a complex structure and is Laramian age of folding. Its continuation is the northern cordillera of the island of Haiti. The Cayman Sierra Maestra fold structure, which is of Miocene age, begins with the Mayan Mountains in the Yucatan Peninsula, then continues as the Cayman submarine ridge and the Southern Cuba Sierra Maestra mountain range. The Lesser Antilles arc includes a number of volcanic formations (including three volcanoes, such as Montagne Pelee). Composition of 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 Caribbean Andes mountain range, passing to the east into the islands of Trinidad and Tobago. Island arcs and submarine ridges divide the floor of the Caribbean Sea into several basins, which are lined by a thick layer of carbonate sediments. The deepest of them is Venezuela (5420 m). There are also two deep-sea 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 - areas 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. Adjacent to it from the east is the South Sandwich deep-sea 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 continental crust. The suboceanic crust is developed only in patches 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 represents an island arc, which is bounded on the south by the Hellenic Trench, in turn on the south, framed by the uplift of the East Mediterranean Wall. 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 remain here (Vesuvius, Etna, Santorini).
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 Ridge. 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 latitude 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 surface (forming islands) and underwater active volcanoes. To the south of the Azores Plateau, in the rift zone, basalts lie under calcareous silts 300 m thick, and under them a blocky mixture of ultramafic and mafic rocks. The area is currently experiencing vigorous volcanic and hydrothermal activity. 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 Romanche depression with depths of up to 7856 m is associated with deep-sea faults.
The South Atlantic Ridge has a meridional strike. Rift valleys are well defined here, the number of transverse faults is fewer, so this ridge looks more monolithic compared to the North Atlantic Ridge. In the southern and middle parts of the ridge there are the volcanic plateaus of the Ascension, the islands of Tristan da Cunha, Gough, and Bouvet. The plateau is confined to active and recently active volcanoes. From Bouvet Island, the South Atlantic Ridge turns east, circles Africa and, in the Indian Ocean, meets the West Indian Mid-Range.
The Mid-Atlantic Ridge divides the floor of the Atlantic Ocean into two almost equal parts. In the western part, mountain structures: the Newfoundland Ridge, the Baracuda Ridge, the Ceara and Rio Grande uplifts divide the ocean floor into basins: Labrador, Newfoundland, North American, Guiana, Brazil, Argentina. East of the mid-ocean ridge, the bed is divided by a submarine base Canary Islands, the rise of the Cape Verde islands, the Guinea rise and the Whale Ridge into basins: 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 ocean floor area, the sediment thickness is more than 1 km. Under the sedimentary rocks a layer was discovered consisting of volcanic rocks and compacted sedimentary rocks.
In areas of basins remote from the underwater margins of continents, abyssal hills are common along the periphery of mid-ocean ridges. 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, stretching on either side of the Mid-Ocean Ridge.
The sediments of the shallow part of the Atlantic Ocean are mostly represented by terrigenous and biogenic sediments, and occupy 20% of the area of the ocean floor. Of the deep-sea sediments, the most common are calcareous foraminiferal silts (65% of the ocean floor area). In the Mediterranean and Caribbean Seas, in the southern zone of the South Atlantic Ridge, pteropod deposits became widespread. Deep-sea red clay occupies about 20% of the ocean floor and is confined to the deepest parts of ocean basins. In the Angola Basin, radilarium oozes are found. In the southern part of the Atlantic there are siliceous diatom deposits with authigenic silica content of 62-72%. In the zone of the Western Wind Current there is a continuous field of diatomaceous oozes, 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.
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, the Icelandic and Antarctic lows. In addition, two anticyclones are constantly active in the subtropics: the Azores and the South Atlantic. They are separated by an equatorial region of low pressure. This distribution of pressure 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 Antarctic seas and the Mediterranean Sea. For surface waters They are characterized by 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. 
In the vastness of the Atlantic, all climatic zones of the planet are represented. Tropical latitudes are characterized by slight seasonal temperature fluctuations (average 20 °C) and heavy precipitation. To the north and south of the tropics there 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 vortices, 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 in the region of 10-15° N latitude. and move to the Azores and Ireland. Further to the north and south follow the subtropical zones, where in the coldest month the temperature drops to 10 °C, and in winter cold air masses from polar low pressure areas bring heavy precipitation. In temperate latitudes, the average temperature of the warmest month is between 10-15 °C, and the coldest month is −10 °C. There are also significant daily temperature changes here. The temperate zone is characterized by fairly uniform 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 polar zones. In the Northern Hemisphere, this boundary runs in a wide band between 50° N latitude. (Labrador) and 70°N. (coast of Northern Norway). In the Southern Hemisphere, the circumpolar zone begins closer to the equator - approximately 45-50° S. The lowest temperature (-34 °C) was recorded in the Weddell Sea. 
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, crossing the ocean from east to west. The Northern Trade Wind Current near the Lesser Antilles is divided: into a northern branch, continuing northwest along the coast 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 flowing through the Yucatan Strait into the Gulf of Mexico, and leaves it through the Strait of Florida, 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 eastern and then a northeastern direction and is called the North Atlantic Current. The main flow of water from 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 from the Arctic Ocean - the East Greenland Current, which runs along the eastern coast of Greenland, and the Labrador Current, which goes around Labrador, Newfoundland and penetrates south to Cape Hatteras, pushing the Gulf Stream away from the coast of North America. 
The Southern Trade Wind Current partially enters the northern hemisphere, and at Cape San Roque it divides into two parts: one of them goes to the south, forming the Brazil Current, the other turns to the north, forming the Guiana Current, which goes into the Caribbean Sea. The Brazilian Current in the La Plata region meets the cold Falkland Current (a branch 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 Southern Trade Wind Current.
There are several tiers of deep-sea 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 as 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. The subsurface Lomonosov Current has been discovered in the equatorial zone of the ocean. 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 highest tide values are confined to the Atlantic Ocean, which are observed in the fiord 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 fluctuations in Atlantic waters throughout the year are not large: in the equatorial-tropical zone - no more than 1-3°, in the subtropics and temperate latitudes - within 5-8°, in subpolar latitudes - about 4° in the north and no more than 1° on South. The warmest waters are in 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 increase much faster and at 60°S. fluctuate around 0 °C. In general, the ocean in the southern hemisphere is colder than in the northern hemisphere. In the northern hemisphere, the western part of the ocean is colder than the eastern, in the southern hemisphere it is vice versa.
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 recorded, salinity decreases to 34 ‰. A sharp desalination of water occurs in the estuary 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 in the area of 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 extent in September-October. The total removal from the Arctic Ocean is estimated at an average of 900,000 km³/year, and from the surface of Antarctica - 1630 km³/year.
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 nutrients in relation to the overlying waters, and extends north to the region of 20° N. 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 drops to levels of 2500-2750 m and wedges south of 45°S. The main feature of these waters is their high salinity and temperature relative to the surrounding waters. In the bottom layer of the Strait of Gibraltar, a salinity of up to 38 ‰ and a temperature of up to 14 °C are noted, 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 drop 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, North Atlantic deep water is formed, which descends as a result of winter cooling of relatively salty 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 approximately 50°S. The North Atlantic deep water differs from the overlying and underlying 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 as a result of the mixing of 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 0.8ºC in the north of this sea, 0.6ºC near the equator and 1.8ºC near the Bermuda Islands. The Arctic bottom water mass has lower salinity values compared to the overlying waters and in the South Atlantic is characterized by an increased content of nutrients.
The bottom flora of the northern part of the Atlantic is represented by brown (mainly fucoids, and in the sublittoral zone - kelp and alaria) and red algae. In the tropical zone, green (caulerpa), red (calcareous lithothamnia) and brown algae(sargassum). In the southern hemisphere, bottom vegetation is mainly represented by kelp forests. There are 245 species of phytoplankton in the Atlantic Ocean: peridinea, coccolithophores, and diatoms. The latter have a clearly defined zonal distribution; their maximum number lives in the temperate latitudes of the northern and southern hemispheres. The population of diatoms is most dense in the zone of the Western Wind Current. 
The distribution of the fauna of the Atlantic Ocean has a pronounced zonal character. In subantarctic and Antarctic waters, notothenia, whiting and others are of commercial importance. Benthos and plankton in the Atlantic are poor in both species and biomass. In the subantarctic zone and in the adjacent temperate zone, biomass reaches its maximum. The zooplankton is dominated by copepods and pteropods; the nekton is dominated by mammals such as whales (blue whale), pinnipeds, and their fish - nototheniids. In the tropical zone, zooplankton is represented by numerous species of foraminifera and pteropods, several species of radiolarians, copepods, larvae of mollusks and fish, as well as siphonophores, various jellyfish, large cephalopods (squid), and, among benthic forms, octopuses. Commercial fish are represented by mackerel, tuna, sardines, and 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 diversity of species. Of the commercial fish, the most important are herring, cod, haddock, halibut, and sea bass. Foraminifera and copepods are the most characteristic of zooplankton. 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 species of fish, sponges, and hydroids. Several species of endemic polychaetes, isopods, and holothurians have been found in the Puerto Rico Trench. 
Since time immemorial, the Atlantic Ocean has been a place of intense marine fishing and hunting. The sharp increase in capacity and the revolution in fishing technology have led to alarming proportions. With the invention of the harpoon cannon, whales were largely exterminated in the North Atlantic at the end of the 19th century. Due to the massive development of pelagic whaling in Antarctic waters in the mid-20th century, whales here were also close to complete extermination. Since the 1985-1986 season, the International Whale Commission has imposed a complete moratorium on commercial whaling of any species. 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 ever happened at sea. The accident spilled about 5 million barrels of crude oil into the Gulf of Mexico and polluted 1,100 miles of coastline. The authorities have introduced a fishing ban; more than a third of the entire water area of the Gulf of Mexico is closed to fishing. As of November 2, 2010, 6,814 dead animals had 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, the mortality rate of cetaceans in the northern Gulf of Mexico increased several times compared to previous years (2002-2009). 
A large garbage patch of plastic and other waste has formed in the Sargasso Sea, formed by ocean currents that gradually concentrate trash thrown into the ocean in one area.
There is radioactive contamination in some areas of the Atlantic Ocean. Waste from nuclear power plants and research centers is discharged into rivers and coastal seas, and sometimes into the deep ocean. Areas of the Atlantic Ocean heavily contaminated with radioactive waste include the North, Irish, Mediterranean Seas, the Bay of Mexico, the Bay of Biscay and the Atlantic coast of the United States. In 1977 alone, 7,180 containers containing 5,650 tons of radioactive waste were dumped into the Atlantic. The U.S. Environmental Protection Agency reported seabed contamination 120 miles east of the Maryland-Delaware border. There, 14,300 cemented containers containing plutonium and cesium were buried there for 30 years; radioactive contamination exceeded “expected” by 3-70 times. In 1970, the United States sank the Russell Brigge, 500 km off the coast of Florida, carrying 68 tons of nerve gas (sarin) placed in 418 concrete containers. In 1972, in the ocean waters north of the Azores, Germany sank 2,500 metal barrels containing 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 water areas. 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 coast of the United States and in the open ocean).
On the shores of the Atlantic Ocean and its constituent seas there are states and dependent territories:
Long before the era of great geographical discoveries, numerous ships plied the expanses of the Atlantic. As early as 4000 BC, the peoples of Phoenicia conducted 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 testimony of the Greek historian Herodotus, made voyages around Africa, and through the Strait of Gibraltar and around the Iberian Peninsula they reached the British Isles. By the 6th century BC, Ancient Greece, having a huge military merchant fleet at that time, sailed to the shores of England and Scandinavia, in the Baltic Sea and to the western coast of Africa. In the X-XI centuries. The Vikings wrote a new page in the study of the North Atlantic Ocean. According to most researchers of pre-Columbian discoveries, 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 sailors 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 circumnavigated Africa from the south. In 1492, Christopher Columbus's expedition mapped many of the Caribbean islands and the vast continent later called America. In 1497, Vasco da Gama walked from Europe to India, circumnavigating Africa from the south. In 1520, Ferdinand Magellan, during his first circumnavigation of the world, passed the Strait of Magellan from the Atlantic to Pacific Ocean. At the end of the 15th century, the rivalry between Spain and Portugal for supremacy in the Atlantic became so intense that the Vatican was forced to intervene in the conflict. In 1494, an agreement was signed, which established the so-called along 48-49° west longitude. "Papal Meridian" All lands to the west of it were given to Spain, and to the east - to Portugal. In the 16th century, as colonial wealth was being developed, the waves of the Atlantic began to regularly ply 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 along the same route. 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, wrote their names in 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 off the coast of Denmark, and the beginning of serious scientific research was started in 1803-1806 by the first Russian round-the-world expedition under the command of naval officer Ivan Kruzenshtern. Temperature measurements at various depths were carried out by J. Cook (1772), O. Saussure (1780), and others. Participants in subsequent trips measured the temperature and specific gravity of water at different depths, took samples of water transparency and determined the presence of underwater currents. The collected material made it possible to compile a map of the Gulf Stream (B. Franklin, 1770), a map of the depths of the northern part of the Atlantic Ocean (M. F. Morey, 1854), as well as maps of winds and ocean currents (M. F. Morey, 1849-1860) and conduct other studies.
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 ocean waters, flora and fauna, bottom topography and soils, the first map of ocean depths 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-screw corvette Vityaz (1886-1889), on the German ships Valdivia (1898-1899) and Gauss (1901-1903) and others. The largest work was carried out on the English 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. As part of the International Geophysical Year (1957-1958), international forces (especially the USA and the USSR) carried out research, which resulted in the compilation of new bathymetric and marine navigation maps of the Atlantic Ocean. In 1963-1964, the Intergovernmental Oceanographic Commission conducted a large expedition to study 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 ocean measurements have been made from space satellites. The result was a bathymetric atlas of the oceans released in 1994 by the American National Geophysical Data Center with a map resolution of 3-4 km and a depth accuracy of ±100 m.
The Atlantic Ocean provides 2/5 of the world's catch and its share has been decreasing over the years. In subantarctic and Antarctic waters, notothenia, 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 fish species, fishing volumes declined sharply, but after the introduction of strict limits, fish stocks are gradually recovering. There are several international fisheries conventions in force in the Atlantic Ocean basin, which aim at the effective and rational use of biological resources, based on the application of scientifically based measures to regulate fishing.
The Atlantic Ocean occupies a leading place in world shipping. Most of the routes lead from Europe to North America. The main navigable straits of the Atlantic Ocean: Bosphorus and Dardanelles, Gibraltar, English Channel, Pas de Calais, Baltic straits (Skagerrak, Kattegat, Oresund, Great and Little 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, and also to the Indian Ocean by the artificial Suez Canal through the Mediterranean Sea. Largest ports: St. Petersburg (general cargo, petroleum products, metals, timber cargo, 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, chemical cargo, 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: cars, fertilizers, cast iron, building materials, food), Port Said, Alexandria (export: cotton, rice, ores, import: equipment, metals, petroleum products, fertilizers), Casablanca (export: phosphorites, ores, citrus fruits, cork, food, import: equipment, fabrics, petroleum products) , Dakar (groundnuts, dates, cotton, livestock, fish, ores, import: equipment, petroleum products, food), Cape Town, Buenos Aires (export: wool, meat, grain, leather, vegetable oil, flaxseed, cotton, import : equipment, iron ore, coal, oil, industrial 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, construction raw materials, cars, grain, rolled steel, equipment, coffee, fruits, food), Savannah, New York (general cargo, oil, chemical cargo, equipment, pulp, paper, coffee, sugar, metals), Montreal (grain, oil, cement, coal, timber, metals, paper, asbestos, 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 connection goes through Lisbon, the Azores and Bermuda. The air route from Europe to South America passes through Lisbon, Dakar and then across the narrowest part of the Atlantic Ocean to Rio de Janeiro. Airlines from the United States to Africa pass through the Bahamas, Dakar and Robertsport. On the shores of the Atlantic Ocean there are spaceports: Cape Canaveral (USA), Kourou (French Guiana), Alcantara (Brazil).
Mineral extraction, primarily oil and gas, is carried out on 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. Mining is also underway on the North Sea shelf natural gas. There is industrial mining of sulfur in the Gulf of Mexico, and iron ore off the island of Newfoundland. Diamonds are mined from sea deposits on the South African continental shelf. Next most important group mineral resources form coastal deposits of titanium, zirconium, tin, phosphorites, monazite and amber. Coal, barite, sand, pebbles and limestone are also mined from the seabed.
Tidal power stations have been built on the shores of the Atlantic Ocean: La Rance on the Rance River in France, Annapolis in the Bay of Fundy in Canada, and Hammerfest in Norway.
The recreational resources of the Atlantic Ocean are characterized by significant 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. Main recreational areas: Mediterranean coast 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 on the Atlantic coast of North and South America. 
Recently, the popularity of Mediterranean countries such 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), the following 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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Includes all the seas and oceans of the Earth. It occupies about 70% of the planet's surface and contains 96% of all water on the planet. The world ocean consists of four oceans: the Pacific, Atlantic, Indian and Arctic.
Sizes of the oceans: Pacific - 179 million km2, Atlantic - 91.6 million km2, Indian - 76.2 million km2, Arctic - 14.75 million km2
The boundaries between oceans, as well as the boundaries of seas within oceans, are drawn rather arbitrarily. They are determined by land areas delimiting the water space, internal currents, differences in temperature and salinity.
Seas are divided into internal and marginal. Inland seas protrude quite deeply into the land (for example,), and marginal seas adjoin the land with one edge (for example, the Northern, Japanese).
The Pacific is the largest of the oceans. It is located in both the northern and southern hemispheres. In the east, its border is the coast of North and, in the west - the coast of and, in the south - Antarctica. It owns 20 seas and more than 10,000 islands.
As the Pacific Ocean covers all but the coldest,
it has a diverse climate. over the ocean varies from +30°
The water temperature in the Atlantic Ocean ranges from -1 °C to + 26 °C, the average water temperature is +16 °C.
The average salinity of the Atlantic Ocean is 35%.
The organic world of the Atlantic Ocean is distinguished by a wealth of green plants and plankton.
Most of Indian Ocean located in warm latitudes, humid monsoons dominate here, determining the climate of East Asian countries. The southern edge of the Indian Ocean is sharply cold.
Indian Ocean currents change direction depending on the direction of the monsoons. The most significant currents are the Monsoon, Trade Wind and.
The Indian Ocean is diverse; there are several ridges, between which there are relatively deep basins. The deepest point of the Indian Ocean is the Java Trench, 7 km 709 m.
The water temperature in the Indian Ocean ranges from -1°C off the coast of Antarctica to +30°C, the average water temperature is +18°C.
The average salinity of the Indian Ocean is 35%.
Much of the Arctic Ocean is covered in thick ice—almost 90% of the ocean surface in winter. Only near the coast does the ice freeze to the land, while most of the ice drifts. Drifting ice is called "pack".
The ocean is located entirely in northern latitudes and has a cold climate.
A number of large currents are observed in the Arctic Ocean: the Trans-Arctic Current passes along the north of Russia, as a result of interaction with more warm waters A current is born in the Atlantic Ocean.
The relief of the Arctic Ocean is characterized by a developed shelf, especially off the coast of Eurasia.
The water under the ice always has a negative temperature: -1.5 - -1°C. In summer, the water in the seas of the Arctic Ocean reaches +5 - +7 °C. The salinity of ocean water decreases significantly in summer due to the melting of ice and, this applies to the Eurasian part of the ocean, deep Siberian rivers. So in winter the salinity in different parts is 31-34% o, in summer off the coast of Siberia it can be up to 20% o.
Maritime transport is the most important element of international trade. Countries such as and others, cut off from continents and not having sufficient resources of their own, are entirely dependent on. This is associated with a potential environmental hazard: the wreck of a ship carrying oil, fuel oil, coal and others causes serious damage.
