To the question: Resources of the ATLANTIC OCEAN? given by the author Nasopharynx the best answer is Mineral Resources. Among the mineral resources of the Atlantic Ocean vital importance have oil and gas (map to the station. World Ocean). North America has oil and gas shelves in the Labrador Sea, the bays of St. Lawrence, Nova Scotia, and Georges Bank. Oil reserves on the eastern shelf of Canada are estimated at 2.5 billion tons, gas reserves at 3.3 trillion. m3, on the eastern shelf and continental slope of the USA - up to 0.54 billion tons of oil and 0.39 trillion. m3 of gas. More than 280 fields have been discovered on the southern shelf of the United States, and more than 20 fields off the coast of Mexico (see Gulf of Mexico oil and gas basin). More than 60% of Venezuela's oil is produced in the Maracaibo Lagoon (see Maracaibo oil and gas basin). The deposits of the Gulf of Paria (Trinidad Island) are actively exploited. The total reserves of the Caribbean Sea shelves amount to 13 billion tons of oil and 8.5 trillion. m3 of gas. Oil and gas bearing areas have been identified on the shelves of Brazil (Toduz-yc-Santos Bay) and Argentina (San Xopxe Bay). Oil fields have been discovered in the North (114 fields) and Irish Seas, the Gulf of Guinea (50 on the Nigerian shelf, 37 off Gabon, 3 off Congo, etc.).
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Mineral resources. Among the mineral resources of the Atlantic Ocean, the most important are oil and gas (map to the station. World Ocean). North America has oil and gas shelves in the Labrador Sea, the bays of St. Lawrence, Nova Scotia, and Georges Bank. Oil reserves on the eastern shelf of Canada are estimated at 2.5 billion tons, gas reserves at 3.3 trillion. m3, on the eastern shelf and continental slope of the USA - up to 0.54 billion tons of oil and 0.39 trillion. m3 of gas. More than 280 fields have been discovered on the southern shelf of the United States, and more than 20 fields off the coast of Mexico (see Gulf of Mexico oil and gas basin). More than 60% of Venezuela's oil is produced in the Maracaibo Lagoon (see Maracaibo oil and gas basin). The deposits of the Gulf of Paria (Trinidad Island) are actively exploited. The total reserves of the Caribbean Sea shelves amount to 13 billion tons of oil and 8.5 trillion. m3 of gas. Oil and gas bearing areas have been identified on the shelves of Brazil (Toduz-yc-Santos Bay) and Argentina (San Xopxe Bay). Oil fields have been discovered in the North (114 fields) and Irish Seas, the Gulf of Guinea (50 on the Nigerian shelf, 37 off Gabon, 3 off Congo, etc.).
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Valentin Bibik Student (193) 1 year ago
Natural resources: oil and gas deposits, fish, marine mammals (pinnipeds and whales), sand and gravel mixtures, placer deposits, ferromanganese nodules, precious stones
Definition: This indicator contains information about natural resources, mineral reserves, energy, fisheries and forest resources.
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Andrey Zelenin Student (140) 1 month ago
fish, oil, oyster harvesting.
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Maxim Surmin Student (197) 3 weeks ago
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Organic world The Atlantic and Pacific Oceans have much in common (Fig. 37). Life in the Atlantic Ocean is also distributed zonally and is concentrated mainly along the coasts of continents and in surface waters.
The Atlantic Ocean is poorer than the Pacific Ocean biological resources. This is due to his relative youth. But the ocean still provides 20% of the world's fish and seafood catch. This is first of all herring, cod, sea bass, hake, tuna.
In temperate and polar latitudes there are many whales, in particular sperm whales and killer whales. Characteristic sea crayfish - lobster, lobsters.
Economic development of the ocean is also associated with mineral resources(Fig. 38). A significant part of them is mined on the shelf. In the North Sea alone, more than 100 oil and gas fields have been discovered, hundreds of boreholes have been constructed, and oil and gas pipelines have been laid along the bottom. More than 3,000 special platforms from which oil and gas are produced operate on the shelf of the Gulf of Mexico. Coal is mined in the coastal waters of Canada and Great Britain, and diamonds are mined off the southwestern coast of Africa. Long since sea water extract table salt.
Recently, not only on the shelf, but also at significant depths of the Atlantic Ocean, huge reserves of oil and natural gas. The coastal zones of Africa, in particular, turned out to be rich in fuel resources. Other areas of the Atlantic floor are also extremely rich in oil and gas - off the northeastern coast of North America, not far from the eastern coast of South America.
The Atlantic Ocean is crossed in different directions by important sea routes. It is no coincidence that the largest ports in the world are located here, among them the Ukrainian one - Odessa. Material from the site http://worldofschool.ru
Active economic activity humans in the Atlantic Ocean has caused significant pollution his water. It is especially noticeable in some seas of the Atlantic Ocean. Thus, the Mediterranean Sea is often called a “sewage” because waste is dumped here industrial enterprises. A large amount of pollutants also comes with river runoff. In addition, about hundreds of thousands of tons of oil and petroleum products enter its waters every year as a result of accidents and other reasons.
The Atlantic Ocean is the second largest ocean on Earth after the Pacific. Like the Pacific, it extends from subarctic latitudes to the subantarctic, that is, from the underwater threshold separating it from the Arctic Ocean in the north to the shores of Antarctica in the south. In the east, the Atlantic Ocean washes the shores of Eurasia and Africa, in the west - North and South America (Fig. 3).
Not only in the geographical location of the largest oceans on Earth, but also in many of their features - climate formation, hydrological regime, etc. - there is much in common. Nevertheless, the differences are also very significant, which are associated with a large difference in size: in terms of surface area (91.6 million km2) and volume (about 330 million km3), the Atlantic Ocean is approximately half as large as the Pacific Ocean.
The most narrow part The Atlantic Ocean falls at the same latitudes where the Pacific Ocean reaches its greatest extent. The Atlantic Ocean differs from the Pacific Ocean in the wider development of its shelf, especially in the area of Newfoundland and off the southeastern coast of South America, as well as in the Bay of Biscay, the North Sea and the British Isles. The Atlantic is also characterized by a large number of mainland islands and island archipelagos, which relatively recently lost contact with the continents (Newfoundland, Antilles, Falklands, British, etc.). Islands of volcanic origin (Canary, Azores, St. Helena, etc.) compared to Pacific Ocean few.
The shores of the Atlantic Ocean are most severely dissected north of the equator. There, going deep into the land of North America and Eurasia, are the most significant seas related to it: the Gulf of Mexico (actually a semi-enclosed sea between the Florida and Yucatan peninsulas and the island of Cuba), the Caribbean, North, Baltic, as well as the intercontinental Mediterranean Sea, connected by straits with the Marmara, Black and Azov inland seas. North of the equator, off the coast of Africa, lies the vast Gulf of Guinea, wide open to the ocean.
The formation of the modern depression of the Atlantic Ocean began approximately 200 million years ago, in the Triassic, with the opening of a rift on the site of the future Tethys Ocean and the division of the Pangea continent into Laurasia and Gondwana (see map of continental drift). Subsequently, Gondwana was divided into two parts - African-South American and Australian-Antarctic and the formation of the western part of the Indian Ocean; the formation of a continental rift between Africa and South America and their movement to the north and northwest; creation of a new ocean floor between North America and Eurasia. Only at the site of the North Atlantic, on the border with the Arctic Ocean, did the connection between the two continents persist until the end of the Paleogene.
At the end of the Mesozoic and Paleogene, as a result of the movement towards Eurasia of the most stable part of the broken Gondwana - the African lithospheric plate, as well as the Hindustan block, the closure of Tethys occurred. The Mediterranean (Alpine-Himalayan) orogenic belt and its western continuation, the Antillean-Caribbean fold system, were formed. The intercontinental basin of the Mediterranean Sea, the Sea of Marmara, the Black and Azov, as well as the seas and gulfs of the northern part of the Indian Ocean, which were discussed in the corresponding section, should be considered as fragments of the closed ancient Tethys ocean. The same “remnant” of Tethys in the west is the Caribbean Sea with the adjacent land and part of the Gulf of Mexico.
The final formation of the Atlantic Ocean basin and the surrounding continents occurred in the Cenozoic era.
Along the entire ocean from north to south, occupying its axial part, runs the Mid-Atlantic Ridge, separating the continental-oceanic lithospheric plates located on both sides: the North American, Caribbean and South American in the west and the Eurasian and African in the east. . The Mid-Atlantic Ridge has the most pronounced features of the mid-ocean ridges of the World Ocean. The study of this particular ridge laid the foundation for the study of the global system of mid-ocean ridges as a whole.
From the border with the Arctic Ocean off the coast of Greenland to the connection with the African-Antarctic Ridge at Bouvet Island in the south, the Mid-Atlantic Ridge has a length of over 18 thousand km and a width of 1 thousand km. It accounts for approximately a third of the area of the entire ocean floor. A system of deep longitudinal faults (rifts) runs along the arch of the ridge; transverse (transform) faults cross it along its entire length. The areas of the most active manifestation of ancient and modern, underwater and above-water, rift volcanism in the northern part of the Mid-Atlantic Ridge are the Azores Islands at 40° N latitude. and the unique, largest volcanic island on Earth - Iceland on the border with the Arctic Ocean.
The island of Iceland is located directly on the Mid-Atlantic Ridge; in the middle it is crossed by a rift system - the “spreading axis”, bifurcating in the southeast. Almost all the extinct and active volcanoes of Iceland rise along this axis, the emergence of which continues to this day. Iceland can be considered as a “product” of the expansion of the ocean floor, which has been going on for 14-15 million years (H. Rast, 1980). Both halves of the island are moving apart from the rift zone, one, together with the Eurasian plate, to the east, the other, together with the North American plate, to the west. The movement speed is 1 - 5 cm per year.
South of the equator, the Mid-Atlantic Ridge retains its integrity and typical features, but differs from the northern part in less tectonic activity. The centers of rift volcanism here are the islands of Ascension, St. Helena, and Tristan da Cunha.
On both sides of the Mid-Atlantic Ridge lies an ocean floor composed of basaltic crust and thick layers of Meso-Cenozoic sediments. In the structure of the surface of the bed, as in the Pacific Ocean, there are numerous deep-sea basins (more than 5000 m, and the North American Basin is even more than 7000 m deep), separated from each other by underwater rises and ridges. The basins of the American side of the Atlantic are Newfoundland, North American, Guiana, Brazilian and Argentine; from Eurasia and Africa - Western European, Canary, Angolan and Cape.
The largest rise of the Atlantic Ocean bed is the Bermuda Plateau within the North American Basin. Basically consisting of oceanic basalts, it is covered by a two-kilometer layer of sediment. On its surface, located at a depth of 4000 m, volcanoes rise, topped with coral structures, forming the Bermuda archipelago. Opposite the coast of South America, between the Brazilian and Argentine basins, is the Rio Grande Plateau, also covered by thick strata sedimentary rocks and topped with underwater volcanoes.
In the eastern part of the ocean floor, the Guinea Rise along the lateral rift of the median ridge should be noted. This fault emerges onto the mainland in the Gulf of Guinea region in the form of a continental rift, to which the active Cameroon volcano is confined. Even further south, between the Angola and Cape basins, the underwater blocky Whale Ridge reaches the shores of South-West Africa.
In the main floor of the Atlantic Ocean it borders directly on the underwater margins of the continents. The transition zone is much less developed than in the Pacific Ocean and is represented by only three regions. Two of them - the Mediterranean Sea with adjacent land areas and the Antilles-Caribbean region, located between North and South America - are fragments of the Tethys Ocean, which closed towards the end of the Paleogene, separated from each other during the opening of the middle part of the Atlantic Ocean. Therefore, they have a lot in common in features geological structure bottom, the nature of the relief of underwater and surface mountain structures, types of manifestation of volcanic activity.
The depression of the Mediterranean Sea is separated from the deep basins of the ocean by the Gibraltar threshold with a depth of only 338 m. The smallest width of the Strait of Gibraltar is only 14 km. In the first half of the Neogene, the Strait of Gibraltar did not exist at all, and long time The Mediterranean Sea was a closed basin, isolated from the ocean and the seas that continued it in the east. The connection was restored only at the beginning of the Quaternary period. Peninsulas and groups of mainland islands formed by structures of different ages, the sea is divided into a number of basins, the structure of the bottom of which is dominated by suboceanic type crust. At the same time, a significant part of the bottom of the Mediterranean Sea, belonging to the continental foot and shelf, is composed of continental crust. This is primarily the southern and southeastern parts of its depressions. Continental crust is also characteristic of some deep-sea basins.
In the Ionian Sea, between the Central Mediterranean, Cretan and Levantine basins, the Central Mediterranean Shaft stretches, to which the Hellenic deep-sea trench adjoins with the maximum depth of the entire Mediterranean Sea (5121 m), bordered from the northeast by the arc of the Ionian Islands.
The Mediterranean basin is characterized by seismicity and explosive-effusive volcanism, confined mainly to its central part, i.e. to the subduction zone in the area of the Bay of Naples and adjacent land areas. Along with the most active volcanoes in Europe (Vesuvius, Etna, Stromboli), there are many objects there that indicate manifestations of paleovolcanism and active volcanic activity during historical time. The features of the Mediterranean noted here allow us to consider it “as located in the most late stage development of a transitional region" (O. K. Leontiev, 1982). Fragments of the closed Tethys are also located to the east of the Black and Azov Seas and the Caspian Lake-Sea. The nature features of these reservoirs are discussed in the relevant sections of the regional review of Eurasia.
The second transition region of the Atlantic Ocean is located in its western part, between North and South America, and roughly corresponds to the western sector of the Tethys Ocean. It consists of two semi-enclosed seas, separated from each other and from the ocean floor by peninsulas and island arcs of continental and volcanic origin. The Gulf of Mexico is a depression of Mesozoic age with a depth of more than 4000 m in the central part, surrounded by a wide strip of shelf from the mainland and the Florida and Yucatan peninsulas. The largest reserves of oil and natural gas are concentrated within the adjacent land, on the shelf and adjacent parts of the bay. This is the oil and gas basin of the Gulf of Mexico, which is genetically and economically comparable to the oil and gas basin of the Persian Gulf. The Caribbean Sea, separated from the ocean by the arc of the Antilles, was formed in the Neogene. Its maximum depths exceed 7000 m. On the ocean side, the Antillean-Caribbean transition region is limited by the deep-sea trench of Puerto Rico, the greatest depth of which (8742 m) is at the same time the maximum for the entire Atlantic Ocean. By analogy with the Mediterranean Sea, this area is sometimes called the American Mediterranean.
The third transitional region related to the Atlantic Ocean, the Scotia Sea (Scotia), is located between South America and the Antarctic Peninsula, on both sides of 60° S, i.e. actually in Antarctic waters. In the east, this area is separated from the ocean floor by the South Sandwich deep-sea trench (8325 m) and an arc of volcanic islands of the same name, perched on an underwater rise. The bottom of the Scotia Sea is composed of suboceanic type crust, changing in the west oceanic crust Pacific Ocean bed. The surrounding groups of islands (South Georgia, etc.) are of continental origin.
Vast expanses of shelf, which are also a characteristic feature of the Atlantic Ocean, exist on both its Eurasian and American flanks. This is the result of relatively recent subsidence and flooding of the coastal plains. Even in the first half of the Cenozoic, North America extended almost to the pole and connected with Eurasia in the northwest and northeast. The formation of the Atlantic shelf off the coast of North America should obviously be attributed to the end of the Neogene, and off the coast of Europe - to the Quaternary period. This is associated with the existence of “land” forms in its relief - erosional hollows, dune hills, etc., and in more northern areas - traces of glacial abrasion and accumulation.
The similarities have already been noted above geographical location Atlantic and Pacific oceans, which cannot but influence the peculiarities of climate formation and hydrological conditions of each of them. Approximately the same length from north to south, between the subpolar latitudes of both hemispheres, much large sizes and the massiveness of the land bordering the oceans in the northern hemisphere compared to the southern one, a relatively weak connection and limited opportunities water exchange with the Arctic Ocean and openness towards other oceans and the Antarctic basin in the south - all these features of both oceans determine the similarity between them in the distribution of centers of atmospheric action, the direction of winds, the temperature regime of surface waters and the distribution of precipitation.
At the same time, it should be noted that the Pacific Ocean is almost twice as large in surface area as the Atlantic and the largest wide part it falls in the intertropical space, where it has a connection with the warmest part of the Indian Ocean through the interisland seas and straits of Southeast Asia. The Atlantic Ocean in subequatorial latitudes has the smallest width; it is limited to the east and west by massive land masses of Africa and South America. These features, as well as differences in the age and structure of the ocean basins themselves, create the geographical individuality of each of them, with individual features being more characteristic of the northern parts of the oceans, while in the southern hemisphere the similarities between them are much more pronounced.
The main pressure systems over the Atlantic Ocean, which determine the meteorological situation throughout the year, are the equatorial depression, which, as in the Pacific Ocean, is somewhat expanded towards the summer hemisphere, as well as quasi-stationary subtropical high pressure areas, along the periphery of which towards the equatorial Depressions are driven by trade winds - northeasterly in the northern hemisphere and southeasterly in the southern hemisphere.
In the southern hemisphere, where the ocean surface is only interrupted by land in relatively small areas, all the main pressure systems are extended along the equator in the form of sublatitudinal belts separated by frontal zones, and during the year only slightly shift following the sun towards the summer hemisphere.
In the winter of the southern hemisphere, the southeast trade wind penetrates to the equator and slightly further north, towards the Gulf of Guinea and northern South America. The main precipitation at this time falls in the northern hemisphere, and dry weather prevails on both sides of the Southern Tropic. South of 40° S. Western transport is active, winds blow, often reaching gale force, thick clouds and fogs are observed, and heavy precipitation falls in the form of rain and snow. These are the “roaring forties” latitudes, which have already been discussed in the sections devoted to the nature of the Pacific and Indian oceans. From Antarctica, in high latitudes, southeastern and eastern winds blow, with which icebergs and sea ice are blown to the north.
In the warm half of the year, the main directions of movement of air flows remain the same, but the equatorial trough expands to the south, the southeast trade wind intensifies, rushing into the region low blood pressure precipitation occurs over South America and along its east coast. Western winds in temperate and high latitudes remain the dominant atmospheric process.
Natural conditions in the subtropical and temperate latitudes of the North Atlantic differ significantly from those characteristic of the southern part of the ocean. This is due both to the characteristics of the water area itself and to the size of the land bordering it, the temperature and air pressure above which change sharply throughout the year. The most significant contrasts in pressure and temperature are created in winter, when high pressure centers form over ice-covered Greenland, North America and the interior of Eurasia due to cooling and temperatures not only over land, but also over clogged with ice interisland waters of the Canadian Arctic Archipelago can be very low. The ocean itself, with the exception of the coastal northwestern part, even in February maintains a surface water temperature of 5 to 10 °C. This is due to the influx of warm waters from the south into the northeastern part of the Atlantic and the lack of cold water from the Arctic Ocean.
In the north of the Atlantic Ocean in winter, a closed area of low pressure is formed - the Icelandic, or North Atlantic, minimum. Its interaction with the Azores (North Atlantic) maximum, located at the 30th parallel, creates a predominant westerly wind flow over the North Atlantic, carrying moist-unstable relatively warm air from the ocean to the Eurasian continent. This atmospheric process is accompanied by precipitation in the form of rain and snow at positive temperatures. A similar situation applies to the ocean area south of 40° N. and in the Mediterranean, where it rains at this time.
IN summer season in the northern hemisphere, the high pressure area persists only over the Greenland ice sheet; centers are established over the continents low pressure, The Icelandic low is weakening. Western transport remains the main circulation process in temperate and high latitudes, but it is not as intense as in winter time. The Azores High intensifies and expands, and most of the North Atlantic, including the Mediterranean Sea, is under the influence of tropical air masses and does not receive precipitation. Only off the coast of North America, where moisture-unstable air enters along the periphery of the Azores High, does monsoon-type precipitation occur, although this process is not at all as pronounced as on the Pacific coast of Eurasia.
In summer and especially in autumn, tropical hurricanes arise over the Atlantic Ocean between the northern tropic and the equator (as in the Pacific and Indian oceans at these latitudes), which sweep over the Caribbean Sea, the Gulf of Mexico, Florida with enormous destructive force, and sometimes penetrate far to the north, up to 40° N
Due to the high solar activity observed in recent years off the coast of the Atlantic Ocean, the frequency of tropical hurricanes has increased significantly. In 2005, three hurricanes hit the southern coast of the United States - Katrina, Rita and Emily, the first of which caused enormous damage to the city of New Orleans.
The system of surface currents in the Atlantic Ocean generally follows their circulation in the Pacific Ocean.
In the equatorial latitudes there are two trade wind currents - the Northern Trade Wind and the Southern Trade Wind, moving from east to west. Between them, the Intertrade Countercurrent moves east. The Northern Trade Wind Current passes near 20° N latitude. and off the coast of North America it gradually deviates to the north. The Southern Trade Wind Current, passing south of the equator from the coast of Africa to the west, reaches the eastern protrusion of the South American continent and at Cape Cabo Branco it divides into two branches running along the coast of South America. Its northern branch (Guiana Current) reaches the Gulf of Mexico and, together with the North Trade Wind Current, takes part in the formation of the system of warm currents of the North Atlantic. The southern branch (Brazilian Current) reaches 40° S, where it meets a branch of the circumpolar current of the Western Winds - the cold Falkland Current. Another branch of the Western Winds, which carries relatively cold waters to the north, enters the Atlantic Ocean off the southwestern coast of Africa. This Benguela Current is an analogue of the Peruvian Current of the Pacific Ocean. Its influence can be traced almost to the equator, where it flows into the South Trade Wind Current, closing the southern Atlantic gyre and significantly reducing the temperature of surface waters off the coast of Africa.
The overall pattern of surface currents in the North Atlantic is much more complex than in the southern part of the ocean, and also differs significantly from the system of currents in the northern part of the Pacific Ocean.
A branch of the North Trade Wind Current, strengthened by the Guiana Current, penetrates through the Caribbean Sea and the Yucatan Strait into the Gulf of Mexico, causing a significant increase in water levels there compared to the ocean. As a result, a powerful waste current arises, which, rounding Cuba, emerges through the Strait of Florida into the ocean called the Gulf Stream (“stream from the gulf”). This is how the greatest system of warm surface currents in the World Ocean arises off the southeastern coast of North America.
Gulf Stream at 30°N. and 79°W merges with the warm Antilles Current, which is a continuation of the North Trade Wind Current. Next, the Gulf Stream passes along the edge of the continental shelf to approximately 36° N latitude. At Cape Hatteras, deviating under the influence of the Earth's rotation, it turns east, skirting the edge of the Great Newfoundland Bank, and goes to the shores of Europe under the name of the North Atlantic Current, or “Gulf Stream Drift”.
When leaving the Strait of Florida, the width of the Gulf Stream reaches 75 km, depth - 700 m, and current speed - from 6 to 30 km/h. The average surface water temperature is 26 °C. After merging with the Antilles Current, the width of the Gulf Stream increases 3 times, and the water flow is 82 million m3/s, i.e. 60 times the flow of all rivers on the globe.
North Atlantic Current at 50°N. and 20°W is divided into three branches. The northern one (Irminger Current) goes to the southern and western shores of Iceland, and then goes around the southern coast of Greenland. The main middle branch continues to move northeast, towards the British Isles and the Scandinavian Peninsula, and goes into the Arctic Ocean called the Norwegian Current. The width of its flow north of the British Isles reaches 185 km, depth - 500 m, flow speed - from 9 to 12 km per day. The surface water temperature is 7... 8 °C in winter and 11... 13 °C in summer, which is on average 10 °C higher than at the same latitude in the western part of the ocean. The third, southern, branch penetrates the Bay of Biscay and continues south along the Iberian Peninsula and the northeastern coast of Africa in the form of the cold Canary Current. Flowing into the North Trade Wind Current, it closes the subtropical gyre of the North Atlantic.
The northwestern part of the Atlantic Ocean is mainly influenced by cold waters coming from the Arctic, and different hydrological conditions develop there. In the area of the island of Newfoundland, the cold waters of the Labrador Current move towards the Gulf Stream, pushing warm waters Gulf Stream from the northeastern coast of North America. In winter, the waters of the Labrador Current are 5...8 °C colder than the Gulf Stream; all year round their temperature does not exceed 10 °C; they form a so-called “cold wall”. The convergence of warm and cold waters promotes the development of microorganisms in the upper layer of water and, consequently, the abundance of fish. The Great Newfoundland Bank is especially famous in this regard, where cod, herring, and salmon are caught.
To approximately 43°N. The Labrador Current carries icebergs and sea ice, which, combined with the fogs characteristic of this part of the ocean, pose a great danger to shipping. A tragic illustration is the disaster of the Titanic liner, castaway in 1912, 800 km southeast of Newfoundland.
The water temperature on the surface of the Atlantic Ocean, as in the Pacific, is generally lower in the southern hemisphere than in the northern. Even at 60° N latitude. (with the exception of the northwestern regions), the temperature of surface waters fluctuates throughout the year from 6 to 10 °C. In the southern hemisphere at the same latitude it is close to 0 °C and in the eastern part it is lower than in the western.
The warmest surface waters of the Atlantic (26...28 °C) are confined to the zone between the equator and the Northern Tropic. But even these maximum values do not reach the values observed at the same latitudes in the Pacific and Indian Oceans.
The salinity of surface waters of the Atlantic Ocean is much more varied than in other oceans. Largest values(36-37%o is the maximum value for the open part of the World Ocean) are typical for subtropical regions with low annual precipitation and strong evaporation. High salinity is also associated with the influx of salt water from the Mediterranean Sea through the shallow Strait of Gibraltar. On the other hand, large areas of the water surface have average oceanic and even low salinity. This is due to large amounts of atmospheric precipitation (in equatorial regions) and the desalination effect of large rivers (Amazon, La Plata, Orinoco, Congo, etc.). In high latitudes, salinity decreases to 32-34%o, especially in summer time, is explained by the melting of icebergs and floating sea ice.
The structural features of the North Atlantic basin, the circulation of the atmosphere and surface waters in subtropical latitudes determined the existence here of a unique natural formation called the Sargasso Sea. This is a section of the Atlantic Ocean between 21 and 36 latitudes. and 40 and 70° W. The Sargasso Sea is “boundless, but not limitless.” Its peculiar boundaries can be considered the currents: the North Trade Wind in the south, the Antilles in the southwest, the Gulf Stream in the west, the North Atlantic in the north and the Canary in the east. These boundaries are fluid, so the area of the Sargasso Sea fluctuates between 6 and 7 million km2. Its position roughly corresponds to the central part of the Azores baric maximum. Within the Sargasso Sea are the volcanic and coral islands of the Bermuda archipelago.
The main features of the surface waters of the Sargasso Sea in comparison with the surrounding waters are their low mobility, poor development of plankton and the highest transparency in the World Ocean, especially in summer (to a depth of 66 m). Also characteristic high performance temperature and salinity.
The sea gets its name from floating brown algae belonging to the genus Sargassum. Algae are carried by currents, and the area where they accumulate coincides with the space between the Gulf Stream and the Azores. Their average weight in the Sargasso Sea is about 10 million tons. There are such numbers of them nowhere else in the World Ocean. European and American eels spawn in the waters of the Sargasso Sea at depths of 500-600 m. The larvae of these valuable commercial fish are then transported by currents to the mouths of large rivers, and the adults return to spawn in the Sargasso Sea. They take several years to complete their full life cycle.
The similarities noted above between the Atlantic and Pacific oceans are also manifested in the features of their organic world. This is quite natural, since both oceans, stretching between the northern and southern polar circles and forming in the south, together with the Indian Ocean, a continuous water surface, the main features of their nature, including the organic world, reflect the general features of the World Ocean.
Like the entire World Ocean, the Atlantic is characterized by an abundance of biomass with a relative poverty of the species composition of the organic world in temperate and high latitudes and much greater species diversity in the intertropical space and subtropics.
The temperate and subantarctic zones of the southern hemisphere are included in the Antarctic biogeographic region.
The Atlantic Ocean, as well as other oceans in these latitudes, is characterized by the presence of large mammals in its fauna - fur seals, several species of true seals, and cetaceans. The latter are represented here most fully compared to other parts of the World Ocean, but in the middle of the last century they were subjected to severe extermination. Of the fish, the endemic families of nototheniids and white-blooded pike are characteristic of the South Atlantic. The number of plankton species is small, but its biomass, especially in temperate latitudes, is very significant. Zooplankton includes copepods (krill) and pteropods, while phytoplankton is dominated by diatoms. The corresponding latitudes of the northern part of the Atlantic Ocean (North Atlantic biogeographical region) are characterized by the presence in the organic world of the same groups of living organisms as in the southern hemisphere, but they are represented by other species and even genera. And compared to the same latitudes of the Pacific Ocean, the North Atlantic is distinguished by greater species diversity. This is especially true for fish and some mammals.
Many areas of the North Atlantic have long been and continue to be places of intense fishing. Cod, herring, halibut, sea bass, sprat. Since ancient times, mammals have been hunted in the Atlantic Ocean, especially seals, whales and other marine animals. This led to a severe depletion of the Atlantic's fishing resources compared to the Pacific and Indian oceans.
As in other parts of the World Ocean, the greatest diversity of life forms and the maximum species richness of the organic world is observed in the tropical part of the Atlantic Ocean. The plankton contains numerous foraminifera, radiolarians, and copepods. Nekton is characterized by sea turtles, squids, sharks, and flying fish; Among commercial fish species, tuna, sardines, mackerel are abundant, and in zones of cold currents - anchovies. Among the bottom forms are various algae: green, red, brown (sargassum already mentioned above); Animals include octopuses and coral polyps.
But despite the relative species richness of the organic world in the tropical Atlantic Ocean, it is still less diverse than in the Pacific and even the Indian Oceans. Coral polyps are much less represented here, the distribution of which is limited mainly to the Caribbean; There are no sea snakes or many species of fish. This may be due to the fact that at equatorial latitudes the Atlantic Ocean has the smallest width (less than 3000 km), which is incomparable with the vast expanses of the Pacific and Indian oceans.
TABLE OF CONTENTS
INTRODUCTION
The scientific direction of ocean geography, which emerged as an independent branch of geographical science in the second half of the twentieth century, was officially approved in the decisions of the V and VI Congresses of the Geographical Society of the USSR (1970, 1975) and the I All-Union Conference on Ocean Geography (1983). The main tasks of ocean geography were the study of general geographic patterns within the oceanosphere, the establishment of specific dependencies between natural conditions and ocean ecosystems, between natural resources and the ocean economy, as well as the identification of anomalous regimes of rational environmental management.Physical geography of the ocean deals with the study of the spatial structure and basic physical properties of the ocean as a single natural system, on the one hand, and as part of a more general planetary system - the biosphere - on the other hand. Its tasks include identifying the relationships between the nature of the ocean and continents, large-scale connections between the oceanosphere and the rest of the elements of the Earth’s geographic shell, processes of energy and mass exchange between them, and other phenomena.
The twentieth century, especially its last quarter, was marked by a very intensive increase in anthropogenic impact on the natural environment, which caused an environmental crisis on Earth, which continues in our time. This process covered not only land, but also the World Ocean, especially inland and marginal seas adjacent to economically developed countries. The Atlantic Ocean bears most of the anthropogenic load.
The above circumstances determine the relevance of the chosen topic. Object of study at work is the Atlantic Ocean, subject- its natural resources.
Purpose of the work– analyze the natural resources of the Atlantic. To achieve this goal, we set the following tasks:
- give a general description of the Atlantic Ocean;
- analyze the properties of waters, the composition of flora and fauna, and also pay attention to the minerals of the ocean;
- reveal the features and problems of ocean development.
This work will be useful to everyone who is interested in issues of oceanology, as well as environmental management.
CHAPTER 1. CHARACTERISTICS OF THE ATLANTIC OCEAN
1.1.Geographical location, climatic and hydrological conditions
The Atlantic Ocean is the most studied and developed by people. It got its name from the titan Atlas (after Greek mythology holding the vault of heaven on his shoulders). At different times it was called differently: “The Sea beyond the Pillars of Hercules”, “Atlantic”, “Western Ocean”, “Sea of Darkness”, etc. The name "Atlantic Ocean" first appeared in 1507 on Wald-Seemüller's map, and since then the name has become established in geography.The boundaries of the Atlantic Ocean along the shores of the continents (Eurasia, Africa, the Americas and Antarctica) are natural, with other oceans (the Arctic, Pacific and Indian) - largely conditional.
The Atlantic Ocean borders the Arctic Ocean at 70° N. w. (Baffin Island - Disko Island), then from Cape Brewster (Greenland) along the Icelandic-Farrer threshold to 6° N. w. (Scandinavian Peninsula); with the Pacific Ocean - from about. Oste (Terra del Fuego) to Cape Sternek (Antarctic Peninsula); with the Indian Ocean - 20° east. from Cape Agulhas to Antarctica. The rest of the ocean is limited by the coastlines of Eurasia, Africa, North and South America, and Antarctica (Fig. 1). The given boundaries are officially accepted in our country and are indicated in the Atlas of the Oceans (publishing house of the Ministry of Defense of the USSR and the Navy, 1980). Within the designated limits, the ocean area is 93.4 million km 2, the volume of water is 322.7 million km 3. Water exchange occurs in 46 years, which is 2 times faster than in the Pacific Ocean.
The significant role of the Atlantic in people’s lives is largely explained by purely geographical circumstances:
a large extent (from the Arctic to the Antarctic) between four continents, and it separates mainly flat areas on the continents that are convenient for human settlement and have long been developed by them;
the fact that large and medium-sized rivers flow into the ocean (Amazon, Congo, Niger, Mississippi, St. Lawrence, etc.), which served and serve natural ways messages;
the large ruggedness of the coastline of Europe, the presence of the Mediterranean Sea and the Gulf of Mexico, which contributed to the development of navigation and ocean exploration.
The Atlantic Ocean has several seas: the Baltic, Mediterranean, Black, Marmara, Azov, Caribbean and 3 large bays: Mexican, Biscay and Guinea. The largest islands - Great Britain and Ireland - are located off the coast of Europe. Particularly large clusters of islands are located off the coast of Central America: the Greater and Lesser Antilles, the Bahamas; off the coast of South America - Falkland, in the southern part of the ocean - South Orkney and South Sandwich; off the coast of Africa - the Canaries, Cape Verde, Azores, Madeira, Principe, Sao Tome, etc. In the axial zone of the ocean are the islands of Iceland, Ascension, St. Helena, Tristan da Cunha, on the border with the Arctic Ocean - The largest island on Earth is Greenland.
The climates of the Atlantic are largely determined by its large meridional extent, the peculiarities of the formation of the pressure field, and the unique configuration (there are more water areas in temperate latitudes than in equatorial-tropical latitudes). On the northern and southern outskirts there are huge regions of cooling and the formation of centers of high atmospheric pressure. Constant areas of low pressure are also formed over the ocean in subequatorial and temperate latitudes and high blood pressure- in subtropical ones.
These are the Equatorial and Antarctic depressions, the Icelandic minimum, the North Atlantic (Azores) and South Atlantic maximums 1.
In the southern hemisphere, where the ocean surface is only interrupted by land in relatively small areas, all the main pressure systems are extended along the equator in the form of sublatitudinal belts separated by frontal zones, and during the year only slightly shift following the sun towards the summer hemisphere.
In the winter of the southern hemisphere, the southeast trade wind penetrates to the equator and slightly further north, towards the Gulf of Guinea and northern South America. The main precipitation at this time falls in the northern hemisphere, and dry weather prevails on both sides of the Southern Tropic. South of 40° S. Western transport is active, winds blow, often reaching gale force, thick clouds and fogs are observed, and heavy precipitation falls in the form of rain and snow. These are the “roaring forties” latitudes. From Antarctica, in high latitudes, southeastern and eastern winds blow, with which icebergs and sea ice are blown to the north.
In the warm half of the year, the main directions of air flow remain the same, but the equatorial trough expands to the south, the southeast trade wind intensifies, rushing into an area of low pressure over South America, and precipitation falls along its eastern coast. Western winds in temperate and high latitudes remain the dominant atmospheric process.
Natural conditions in the subtropical and temperate latitudes of the North Atlantic differ significantly from those characteristic of the southern part of the ocean. This is due both to the characteristics of the water area itself and to the size of the land bordering it, the temperature and air pressure above which change sharply throughout the year. The most significant contrasts in pressure and temperature are created in winter, when high pressure centers form over ice-covered Greenland, North America and the interior of Eurasia due to cooling and the temperature not only over land, but also over the ice-clogged interisland waters of the Canadian Arctic Archipelago is very low . The ocean itself, with the exception of the coastal northwestern part, even in February maintains a surface water temperature of 5 to 10 °C. This is due to the influx of warm waters from the south into the northeastern part of the Atlantic and the lack of cold water from the Arctic Ocean.
In the north of the Atlantic Ocean, a closed area of low pressure is formed in winter - the Icelandic, or North Atlantic, minimum. Its interaction with the Azores (North Atlantic) maximum, located at the 30th parallel, creates a predominant westerly wind flow over the North Atlantic, carrying moist-unstable relatively warm air from the ocean to the Eurasian continent. This atmospheric process is accompanied by precipitation in the form of rain and snow at positive temperatures. A similar situation applies to the ocean area south of 40° N. and in the Mediterranean, where it rains at this time.
In the summer season of the northern hemisphere, the high pressure area remains only over the Greenland ice sheet, low pressure centers are established over the continents, and the Icelandic low weakens. Western transport remains the main circulation process in temperate and high latitudes, but it is not as intense as in winter. The Azores High intensifies and expands, and most of the North Atlantic, including the Mediterranean Sea, is under the influence of tropical air masses and does not receive precipitation. Only off the coast of North America, where moist, unstable air enters along the periphery of the Azores High, does monsoon-type precipitation occur, although this process is not at all as pronounced as on the Pacific coast of Eurasia.
In summer and especially in autumn, tropical hurricanes arise over the Atlantic Ocean between the northern tropic and the equator (as in the Pacific and Indian oceans at these latitudes), which sweep over the Caribbean Sea, the Gulf of Mexico, Florida with enormous destructive force, and sometimes penetrate far to the north, up to 40° N
Due to the high solar activity observed in recent years off the coast of the Atlantic Ocean, the frequency of tropical hurricanes has increased significantly. In 2005, three hurricanes hit the southern coast of the United States - Katrina, Rita and Emily, the first of which caused enormous damage to the city of New Orleans.
1.2.Bottom topography
The Mid-Atlantic Ridge runs across the entire ocean (at approximately equal distances from the continental coasts) (Fig. 2).The outlines of the shores of the Atlantic Ocean are extremely remarkable. If Africa and South America, Europe and North America move them close to each other on the map, so that their coastlines align, then the contours of the continents will converge, like two halves of a torn ruble. This coincidence in the outlines of the coasts led some scientists to a rather simple and original conclusion that the listed continents used to form a single supercontinent, in which a giant crack arose under the influence of the Earth’s rotation. America separated from Europe and Africa and drifted along viscous deep rocks to the west, and the depression that formed between them filled with water and turned into the Atlantic Ocean.
Later, when it was established that a huge mountain system, the Mid-Atlantic Ridge, stretched from north to south in the Atlantic Ocean, it was not so easy to explain the origin of the Atlantic Ocean depression by the drift of America. The question arose: if America sailed from Africa, then where did the ridge 300-1500 kilometers wide, the peaks of which rise 1500-4500 meters above the ocean bed, come from between them? Maybe there was no continental drift? Maybe the waves of the Atlantic are walking over the flooded continents? This is precisely the opinion held by most geologists.
But the more information accumulated about the structure of the mysterious ridge, about the details of the bottom topography and the components composing it rocks, the clearer the complexity and seriousness of the problem became to scientists. This was further aggravated by the fact that the scientific data obtained often gave rise to contradictory judgments.
In the process of studying the ocean, it turned out that along the axis of the Mid-Atlantic Ridge there runs a deep valley - a crack that cuts the ridge along almost its entire length. Such valleys usually arise under the influence of tectonic tension forces and are called rift valleys. They are zones of active manifestation of tectonics, seismicity and volcanism in the geological history of the Earth. The discovery of a rift valley on the ocean floor was reminiscent of a giant crack in a hypothetical supercontinent and continental drift. However, this new information and, above all, the relief features of the ridge required a different explanation of the mechanism of continental drift.
Schematically, the Mid-Atlantic Ridge is now represented as a symmetrical mountain structure, where the rift valley serves as the axis of symmetry. It is interesting that earthquakes occurring in the Atlantic Ocean are mostly associated with the Mid-Atlantic Ridge, and most of them are confined to the rift valley. Examining the relief of the ridge and pieces of rocks raised from the bottom, scientists noticed a pattern that surprised them in the geological structure of this mountain structure, namely: the further - be it to the west or east - from the rift valley, the older the bottom topography and the more ancient the mountain rocks become rocks that make up the mysterious underwater mountainous country. Thus, basalt rocks recovered by geologists from the crest of a ridge and from a rift valley, as a rule, are several hundred thousand years old; some basalt samples are several million years old, but not more than five million. In geological terms, these rocks are young. On the flanks of the ridge the basalts are much older than on the ridge; their age reaches 30 million years or more. Even further from the axis of symmetry, closer to the continents, the age of rocks raised from the ocean floor is determined to be 70 million years. It is important to note that no rocks older than 100 million years have been found in the Atlantic Ocean, while on land the oldest rocks are more than three billion years old.
The given information about the age of ocean rocks allows us to consider the Mid-Atlantic Ridge as a fairly young rock formation, which continues to develop and change to this day.
The Atlantic Ocean is second in size only to the Pacific. It is distinguished from other oceans by its highly rugged coastline, forming numerous seas and bays, especially in the northern part. In addition, the total area of river basins flowing into this ocean or its marginal seas is significantly larger than that of rivers flowing into any other ocean. Another difference of the Atlantic Ocean is the relatively small number of islands and the complex bottom topography, which, thanks to underwater ridges and rises, forms many separate basins.
The Atlantic Ocean is located in all climate zones of the Earth. The main part of the ocean is between 40° N latitude. and 42° S – located in subtropical, tropical, subequatorial and equatorial climatic zones. There are high positive air temperatures here all year round. The most severe climate is found in sub-Antarctic and Antarctic latitudes, and to a lesser extent in subpolar and northern latitudes.
CHAPTER 2. NATURAL RICHES OF THE ATLANTIC OCEAN
2.1.Waters and their properties
The zoning of water masses in the ocean is complicated by the influence of land and sea currents. This is manifested primarily in the temperature distribution of surface waters. In many areas of the ocean, isotherms off the coast deviate sharply from the latitudinal direction.The northern half of the ocean is warmer than the southern half, the temperature difference reaches 6°C. The average surface water temperature (16.5°C) is slightly lower than in the Pacific Ocean. The cooling effect is exerted by the waters and ice of the Arctic and Antarctic.
In sub-equatorial latitudes there are two trade wind currents - the Northern Trade Wind and the Southern Trade Wind, moving from east to west. Between them, the Intertrade Countercurrent moves east. The Northern Trade Wind Current passes near 20° N latitude. and off the coast of North America it gradually deviates to the north. The Southern Trade Wind Current, passing south of the equator from the coast of Africa to the west, reaches the eastern protrusion of the South American continent and at Cape Cabo Branco it divides into two branches running along the coast of South America. Its northern branch (Guiana Current) reaches the Gulf of Mexico and, together with the North Trade Wind Current, takes part in the formation of the system of warm currents of the North Atlantic. The southern branch (Brazil Current) reaches 40° S, where it meets a branch of the circumpolar current of the Western Winds - the cold Falkland Current. Another branch of the Western Winds, which carries relatively cold waters to the north, enters the Atlantic Ocean off the southwestern coast of Africa. This Benguela Current is an analogue of the Peruvian Current of the Pacific Ocean. Its influence can be traced almost to the equator, where it flows into the South Trade Wind Current, closing the southern Atlantic gyre and significantly reducing the temperature of surface waters off the coast of Africa.
The overall picture of surface currents in the North Atlantic is much more complex than in the southern part of the ocean.
A branch of the North Trade Wind Current, strengthened by the Guiana Current, penetrates through the Caribbean Sea and the Yucatan Strait into the Gulf of Mexico, causing a significant increase in water levels there compared to the ocean. As a result, a powerful waste current arises, which, rounding Cuba, emerges through the Strait of Florida into the ocean called the Gulf Stream (“stream from the gulf”). This is how the greatest system of warm surface currents in the World Ocean arises off the southeastern coast of North America.
Gulf Stream at 30°N. and 79°W merges with the warm Antilles Current, which is a continuation of the North Trade Wind Current. Next, the Gulf Stream passes along the edge of the continental shelf to approximately 36° N latitude. At Cape Hatteras, deviating under the influence of the Earth's rotation, it turns east, skirting the edge of the Great Newfoundland Bank, and goes to the shores of Europe under the name of the North Atlantic Current, or “Gulf Stream Drift”.
When leaving the Strait of Florida, the width of the Gulf Stream reaches 75 km, its depth is 700 m, and the current speed is from 6 to 30 km/h. The average surface water temperature is 26 °C. After merging with the Antilles Current, the width of the Gulf Stream increases 3 times, and the water flow is 82 million m 3 /s, i.e. 60 times higher than the flow of all rivers on the globe.
North Atlantic Current at 50°N. and 20°W is divided into three branches. The northern one (Irminger Current) goes to the southern and western shores of Iceland, and then goes around the southern coast of Greenland. The main middle branch continues to move northeast, towards the British Isles and the Scandinavian Peninsula, and goes into the Arctic Ocean called the Norwegian Current. The width of its flow north of the British Isles reaches 185 km, depth – 500 m, flow speed – from 9 to 12 km per day. The surface water temperature is 7... 8 °C in winter and 11... 13 °C in summer, which is on average 10 °C higher than at the same latitude in the western part of the ocean. The third, southern, branch penetrates the Bay of Biscay and continues south along the Iberian Peninsula and the northeastern coast of Africa in the form of the cold Canary Current. Flowing into the North Trade Wind Current, it closes the subtropical gyre of the North Atlantic.
The northwestern part of the Atlantic Ocean is mainly influenced by cold waters coming from the Arctic, and different hydrological conditions develop there. In the area of the island of Newfoundland, the cold waters of the Labrador Current move towards the Gulf Stream, pushing the warm waters of the Gulf Stream away from the northeastern coast of North America. In winter, the waters of the Labrador Current are 5...8 °C colder than the Gulf Stream; all year round their temperature does not exceed 10 °C; they form a so-called “cold wall”. The convergence of warm and cold waters promotes the development of microorganisms in the upper layer of water and, consequently, the abundance of fish. The Great Newfoundland Bank is especially famous in this regard, where cod, herring, and salmon are caught.
To approximately 43°N. The Labrador Current carries icebergs and sea ice, which, combined with the fogs characteristic of this part of the ocean, pose a great danger to shipping. A tragic illustration is the disaster of the Titanic, which sank in 1912 800 km southeast of Newfoundland.
The water temperature on the surface of the Atlantic Ocean, as in the Pacific, is generally lower in the southern hemisphere than in the northern. Even at 60° N latitude. (with the exception of the northwestern regions), the temperature of surface waters fluctuates throughout the year from 6 to 10 °C. In the southern hemisphere at the same latitude it is close to 0 °C and in the eastern part it is lower than in the western.
The warmest surface waters of the Atlantic (26...28 °C) are confined to the zone between the equator and the Northern Tropic. But even these maximum values do not reach the values observed at the same latitudes in the Pacific and Indian Oceans.
The salinity of surface waters of the Atlantic Ocean is much more varied than in other oceans. The highest values (36-37%o - the maximum value for the open part of the World Ocean) are characteristic of subtropical regions with low annual precipitation and strong evaporation. High salinity is also associated with the influx of salt water from the Mediterranean Sea through the shallow Strait of Gibraltar. On the other hand, large areas of the water surface have average oceanic and even low salinity. This is due to large amounts of atmospheric precipitation (in equatorial regions) and the desalination effect of large rivers (Amazon, La Plata, Orinoco, Congo, etc.). In high latitudes, a decrease in salinity to 32-34%o, especially in summer, is explained by the melting of icebergs and floating sea ice.
The structural features of the North Atlantic basin, the circulation of the atmosphere and surface waters in subtropical latitudes determined the existence here of a unique natural formation called the Sargasso Sea (Fig. 2). This mysterious area of almost stagnant water lies in the southwestern part of the North Atlantic, between Bermuda and the West Indies. This sea got its name from the Portuguese word “saggaco”, which means “seaweed”. Almost stagnant, but clean and warm water is inhabited by sargassum algae, which are able to live and reproduce afloat (Fig. 3). Thanks to them, conditions here are more reminiscent of a tidal zone rather than an open ocean. Microscopic plankton do not live here because the water temperature is too high.
2.2.Flora
Ocean vegetation is very diverse. Phytobenthos (bottom vegetation) occupies about 2% of the bottom area and is distributed on the shelf to a depth of 100 m. It is represented by green, brown, red algae and some higher plants. The tropical ocean zone has a high species diversity, but a small amount of biomass compared to cold and temperate geographic zones. The northern littoral zone is characterized by brown algae, and for the sublittoral - kelp. Red algae and some types of sea grass are found. Green algae are very common in the tropical zone. Various types of sea lettuce are the largest in size. Among the red algae, porphyry, rhodolinia, chaidrus, and ahnfeltia are widely represented. For many animals, free-floating Sargassum algae, typical of the Sargasso Sea, form a unique biotope. Of the brown algae in the sublittoral zone in the northern part of the ocean, giant representatives of Macrocystis are characteristic. Phytoplankton, unlike phytobenthos, develops throughout the entire body of water. In the cold and temperate zones of the ocean it is concentrated at a depth of up to 50 m, and in the tropical zone - up to 80 m. It is represented by 234 species. Important representatives of phytoplankton are silicon algae, characteristic of temperate and circumpolar regions. In these areas, silicon algae represent more than 95% of the total phytoplankton. Near the equator the amount of algae is insignificant. The mass of phytoplankton ranges from 1 to 100 mg/m3, and in the high latitudes of the Northern and Southern Hemispheres during the period of mass development (sea bloom) it reaches 10 g/m3 or more.2.3.Fauna
The fauna of the Atlantic Ocean is rich and diverse. Animals inhabit the entire thickness of ocean water. The diversity of fauna increases towards the tropics. In polar and temperate latitudes they number thousands of species, in tropical latitudes - tens of thousands.Temperate and cold waters are inhabited by large marine mammals - whales and pinnipeds, fish - herring, cod, perch and flounder; in zooplankton there is a sharp predominance of copepods and sometimes pteropods. There is great similarity between the faunas of the temperate zones of both hemispheres. More than 100 species of animals are bipolar, that is, they live only in cold and temperate zones, these include seals, fur seals, whales, sprat, sardines, anchovies, and many invertebrates, including mussels. The tropical waters of the Atlantic Ocean are characterized by: sperm whales, sea turtles, crustaceans, sharks, flying fish, crabs, coral polyps, scyphoid jellyfish, siphonophores, radiolarians. There are also many dangerous inhabitants: sharks, barracudas, moray eels. There are urchin fish and invertebrate sea urchins, the pricks of which are very painful.
The world of corals is very unique, but the coral structures of the Atlantic are insignificant in comparison with the Pacific Ocean. At a depth of about 4 m off the coast of Cuba, a “sea fan” coral lives, which has the appearance of burdock-shaped leaves penetrated by a network of vessels - this is the soft coral Gongonaria, forming entire thickets - “underwater forests”.
The deep-sea regions of the Atlantic, like other oceans, represent a special environment of enormous pressure, low temperatures and eternal darkness. Here you can find crustaceans, echinoderms, annelids, silicon sponges, sea lilies.
In the Atlantic, there is also an “ocean desert” (“ocean Sahara”) - this is the Sargasso Sea, where the biomass value is no more than 25 mg/m 3, which is primarily due, apparently, to the special gas regime of the sea.
2.4. Minerals
A large number of offshore oil and gas fields have been discovered in the Atlantic Ocean and its seas and are being intensively developed. The richest offshore oil and gas areas in the world include: the Gulf of Mexico, the Maracaibo Lagoon, the North Sea, and the Gulf of Guinea, which are being intensively developed. Three large oil and gas provinces have been identified in the Western Atlantic: 1) from Davis Strait to the latitude of New York (industrial reserves near Labrador and south of Newfoundland); 2) on the Brazilian shelf from Cape Calcañar to Rio de Janeiro (more than 25 fields have been discovered); 3) in the coastal waters of Argentina from the Gulf of San Jorge to the Strait of Magellan. According to estimates, promising oil and gas areas make up about 1/4 of the ocean, and the total potential recoverable oil and gas resources are estimated at more than 80 billion tons. The largest iron ore deposit of Waubana is located off the east coast of the island of Newfoundland (total reserves are about 2 billion tons). Tin deposits are being developed off the coast of Great Britain and Florida. Heavy minerals (ilmenite, rutile, zircon, monazite) are mined off the coast of Florida, in the Gulf of Mexico. off the coast of Brazil, Uruguay, Argentina, the Scandinavian and Iberian Peninsulas, Senegal, and South Africa. The shelf of South-West Africa is an area of industrial diamond mining (reserves of 12 million carats). Gold placers have been discovered off the Nova Scotia Peninsula. Phosphorites were found on the shelves of the USA, Morocco, Liberia, and on the Agulhas Bank. Diamond deposits were discovered off the coast of South-West Africa on the shelf in sediments of ancient and modern rivers. Ferromanganese nodules were found in bottom basins off the coasts of Florida and Newfoundland 2 . Coal, barite, sulfur, sand, pebbles and limestone are also mined from the seabed.Like the entire World Ocean, the Atlantic is characterized by an abundance of biomass with a relative poverty of the species composition of the organic world in temperate and high latitudes and much greater species diversity in the intertropical space and subtropics.
Zooplankton includes copepods (krill) and pteropods, while phytoplankton is dominated by diatoms. The corresponding latitudes of the northern part of the Atlantic Ocean (North Atlantic biogeographical region) are characterized by the presence in the organic world of the same groups of living organisms as in the southern hemisphere, but they are represented by other species and even genera. And compared to the same latitudes of the Pacific Ocean, the North Atlantic is distinguished by greater species diversity. This is especially true for fish and some mammals. Many areas of the North Atlantic have long been and continue to be places of intense fishing. Cod, herring, halibut, sea bass, and sprat are caught on banks off the coast of North America, in the North and Baltic seas. Since ancient times, mammals have been hunted in the Atlantic Ocean, especially seals, whales and other marine animals. This led to a severe depletion of the Atlantic's fishing resources compared to the Pacific and Indian oceans.
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Coastal marine placers rich in ilmenite, rutile, zircon and monocyte are represented by large deposits on the coasts of Brazil and the Florida Peninsula (USA). On a smaller scale, minerals of this type are concentrated off the coast of Argentina, Uruguay, Denmark, Spain, and Portugal. Tin-bearing and ferruginous sands are found on the Atlantic coast of North America and Europe, and coastal-marine placers of diamonds, gold, and platinum are found off the coast of South-West Africa (Angola, Namibia, South Africa). On the shelf of the Atlantic coast of North and South America and Africa (Blake Plateau, off Morocco, Liberia, etc.) phosphorite formations and phosphate sands (the extraction of which is still unprofitable due to lower quality compared to terrestrial phosphorites) have been discovered. Extensive fields of ferromanganese nodules are located in the northwestern part of the ocean, in the North American Basin and on the Blake Plateau. The total reserves of ferromanganese nodules in the Atlantic Ocean are estimated at 45 billion tons. The level of concentration of non-ferrous metals in them (with a low manganese content) is close to that of ore-bearing land rocks. A large number of offshore oil and gas fields have been discovered in the Atlantic Ocean and its seas and are being intensively developed. The richest offshore oil and gas areas in the world include the Gulf of Mexico, the Maracaibo Lagoon, the North Sea, and the Gulf of Guinea, which are being intensively developed. Three large oil and gas provinces have been identified in the Western Atlantic: 1) from Davis Strait to the latitude of New York (industrial reserves near Labrador and south of Newfoundland); 2) on the Brazilian shelf from Cape Calcañar to Rio de Janeiro (more than 25 fields have been discovered); 3) in the coastal waters of Argentina from the Gulf of San Jorge to the Strait of Magellan. According to estimates, promising oil and gas areas make up about 1/4 of the ocean, and the total potential recoverable oil and gas resources are estimated at more than 80 billion tons. Some areas of the Atlantic shelf are rich in coal (Great Britain, Canada), iron ore (Canada, Finland) .
24. Transport system and ports of the Atlantic Ocean.
A leading place among other sea basins in the world. The world's largest oil cargo flow from the Persian Gulf countries on its way to the Atlantic is divided into two branches: one goes around Africa from the south and heads to Western Europe, North and South America, and the other through Suez. Oil from countries North Africa to Europe and, partly, to North America, from the Gulf of Guinea countries to the USA and Brazil. From Mexico and Venezuela to the USA via the Caribbean Sea, and from Alaska via the Panama Canal to ports on the Atlantic coast. Liquefied gas from North African countries (Algeria, Libya) to Western Europe and the USA. In dry bulk transportation - iron ore (from Brazilian and Venezuelan ports to Europe), grain (from the USA, Canada, Argentina - to European ports), phosphorites (from the USA (Florida), Morocco - Western Europe), bauxite and alumina (from Jamaica, Suriname and Guyana in the USA), manganese (from Brazil, West and South Africa), chrome ore (from South Africa and the Mediterranean), zinc and nickel ores (from Canada), timber cargo (from Canada, Scandinavian countries and northern ports Russia to Western Europe). General cargo, which is 2/3 transported by liner vessels. Universal ports with a high level of mechanization. Western Europe - 1/2 of cargo turnover. The English Channel to the Kiel Canal, the east coast of Great Britain, Mediterranean port complexes along the coast of the Gulf of Lyon and the Ligurian Sea. USA from Gulf of Maine to Chesapeake Bay: New York - New Jersey, Ameriport and Hampton Rhodes. The Gulf of Mexico, where there are three main port-industrial complexes (New Orleans and Baton Rouge; Galveston Bay and the Houston Canal; the ports of Beaumont, Port Arthur, and Orange connected to the Gulf of Mexico by canals through Lake Sabine). oil (Amuay, Cartagena, Tobruk) and chemical (Arzev, Alexandria, Abidjan) factories, aluminum (Belen, San Luis, Puerto Madryn), metallurgy (Tubaran, Maracaibo, Warrij), cement (Freeport) industries. the southeastern coast of Brazil (Santos, Rio de Janeiro, Victoria) and in the Gulf of La Plata (Buenos Aires, Rosario, Santa Fe). (Port Harcourt, Lagos, Niger Delta). North African ports are wide open to the sea, and their universal nature requires significant costs to modernize the port facilities (Algeria, Tripoli, Casablanca, Alexandria and Tunisia). On a number of Caribbean islands (Bahamas, Cayman, Virgin Islands), the deepest transshipment terminals for large tankers (400 - 600 thousand deadweight tons) in this part of the ocean have been built.
