The Atlantic Ocean is second in size only to the Pacific Ocean; its area is approximately 91.56 million km 2. 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, significantly more than that of rivers flowing into any other ocean. Another difference Atlantic Ocean is a relatively small number of islands and a complex bottom topography, which, thanks to underwater ridges and uplifts, forms many separate basins.
NORTH ATLANTIC OCEAN
Borders and coastline.
The Atlantic Ocean is divided into northern and southern parts, the border between which is conventionally drawn along the equator. From an oceanographic point of view, however, the southern part of the ocean should include the equatorial countercurrent, located at 5–8° N latitude. The northern border is usually drawn along the Northern Arctic Circle. In some places this boundary is marked by underwater ridges.
In the Northern Hemisphere, the Atlantic Ocean is highly indented coastline. Its relatively narrow northern part is connected to the Arctic Ocean by three narrow straits. In the northeast, the 360 km wide Davis Strait (at the latitude of the Arctic Circle) connects it with the Baffin Sea, which belongs to the Arctic Ocean. In the central part, between Greenland and Iceland, is the Denmark Strait, only 287 km wide at its narrowest point. Finally, in the northeast, between Iceland and Norway, is the Norwegian Sea, approx. 1220 km. In the east, two water areas protruding deeply into the land are separated from the Atlantic Ocean. The more northern one begins North Sea, which to the east passes into the Baltic Sea with the Bothnian and Gulfs of Finland. To the south there is a system of inland seas - the Mediterranean and the Black - total length OK. 4000 km. In the Strait of Gibraltar, which connects the ocean with the Mediterranean Sea, there are two oppositely directed currents, one below the other. The lower position is occupied by the current coming from Mediterranean Sea into the Atlantic Ocean, since Mediterranean waters, due to more intense evaporation from the surface, are characterized by greater salinity and, consequently, greater density.
In the tropical zone in the southwest North Atlantic located in the Caribbean Sea and Gulf of Mexico, connected to the ocean by the Strait of Florida. The coast of North America is indented by small bays (Pamlico, Barnegat, Chesapeake, Delaware and Long Island Sound); to the northwest are the Bays of Fundy and St. Lawrence, the Strait of Belle Isle, Hudson Strait and Hudson Bay.
Islands.
The largest islands are concentrated in the northern part of the ocean; these are the British Isles, Iceland, Newfoundland, Cuba, Haiti (Hispaniola) and Puerto Rico. On eastern outskirts There are several groups of small islands in the Atlantic Ocean - the Azores, Canary Islands, and Cape Verde. Similar groups exist in the western part of the ocean. Examples include the Bahamas, Florida Keys and Lesser Antilles. The archipelagos of the Greater and Lesser Antilles form an island arc surrounding eastern part Caribbean Sea. IN Pacific Ocean similar island arcs are typical for areas of deformation earth's crust. Deep-sea trenches are located along the convex side of the arc.
Bottom relief.
The Atlantic Ocean basin is bordered by a shelf, the width of which varies. The shelf is cut through by deep gorges - the so-called. underwater canyons. Their origin is still controversial. One theory is that the canyons were cut by rivers when sea levels were lower than they are today. Another theory connects their formation with the activity of turbidity currents. It has been suggested that turbidity currents are the main agent responsible for the deposition of sediment on the ocean floor and that they are the ones that cut submarine canyons.
The bottom of the North Atlantic Ocean has a complex, rugged topography formed by a combination of underwater ridges, hills, basins and gorges. Most of the ocean floor, from depths of about 60 m to several kilometers, is covered with thin, muddy sediments that are dark blue or bluish-green in color. A relatively small area is occupied by rocky outcrops and areas of gravel, pebble and sandy deposits, as well as deep-sea red clays.
Telephone and telegraph cables were laid on the shelf in the North Atlantic Ocean to connect North America with Northwestern Europe. Here, the area of the North Atlantic shelf is home to industrial fishing areas that are among the most productive in the world.
A rift zone stretches along the axis of the Mid-Atlantic Ridge.
Currents.
Surface currents in the North Atlantic Ocean move clockwise. The main elements of this big system are facing north warm current The Gulf Stream, as well as the North Atlantic, Canary and Northern Trade Wind (Equatorial) Currents. The Gulf Stream follows from the Strait of Florida and Cuba in a northerly direction along the coast of the United States and approximately 40° N latitude. deviates to the northeast, changing its name to the North Atlantic Current. This current is divided into two branches, one of which follows northeast along the coast of Norway and further into the Arctic Ocean. It is thanks to her that the climate of Norway and all northwestern Europe significantly warmer than would be expected at latitudes corresponding to the area extending from Nova Scotia to southern Greenland. The second branch turns south and further southwest along the coast of Africa, forming a cold Canary Current. This current moves southwest and joins the North Trade Wind Current, which heads west towards the West Indies, where it merges with the Gulf Stream. To the north of the North Trade Wind Current there is an area of stagnant waters, teeming with algae, known as the Sargasso Sea. The cold Labrador Current runs along the North Atlantic coast of North America from north to south, coming from Baffin Bay and the Labrador Sea and cooling the shores of New England.
SOUTH ATLANTIC OCEAN
Borders and coastline.
Some experts attribute everything to the Atlantic Ocean in the south body of water all the way to the Antarctic Ice Sheet; others take it for southern border Atlantic imaginary line connecting Cape Horn in South America to the Cape Good Hope in Africa. The coastline in the southern part of the Atlantic Ocean is much less indented than in the northern part; there are also no inland seas, through which the influence of the ocean could penetrate deep into the continents of Africa and South America. The only large bay on the African coast is the Gulf of Guinea. On the coast of South America large bays also few in number. The southernmost tip of this continent is Tierra del Fuego– has an indented coastline, bordered by numerous small islands.
Islands.
Large islands not in the southern part of the Atlantic Ocean, but there are individual isolated islands, such as Fernando de Noronha, Ascension, Sao Paulo, St. Helena, the Tristan da Cunha archipelago, and in the extreme south - Bouvet, South Georgia, South Sandwich, South Orkney, Falkland Islands.
Bottom relief.
In addition to the Mid-Atlantic Ridge, there are two main submarines in the South Atlantic. mountain ranges. The whale ridge extends from the southwestern tip of Angola to the island. Tristan da Cunha, where it joins the Mid-Atlantic. The Rio de Janeiro Ridge stretches from the Tristan da Cunha Islands to the city of Rio de Janeiro and consists of groups of individual underwater hills.
Currents.
The major current systems in the South Atlantic Ocean move counterclockwise. The South Trade Wind Current is directed to the west. At the protrusion of the eastern coast of Brazil, it splits into two branches: the northern one carries water along the northern coast of South America to the Caribbean, and the southern one, the warm Brazil Current, moves south along the coast of Brazil and joins the Western Winds Current, or Antarctic Current, which heads east , and then to the northeast. Part of this cold current separates and carries its waters north along the African coast, forming the cold Benguela Current; the latter eventually joins the South Trade Wind Current. The warm Guinea Current moves south along the coast of Northwest Africa into the Gulf of Guinea.
Atlantic Ocean is second largest ocean of the planet. It is 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 ocean coastline is strongly indented in the Northern Hemisphere and weakly in the Southern Hemisphere. The greatest depth is 8742 m in the trench Puerto Rico.
The area of the Atlantic Ocean with its seas is 91.6 million km2, the average depth is 3332 m, the maximum depth is 8742 m.
The Atlantic Ocean was formed after the collapse of Gondwana and Laurasia (in the Mesozoic), it is relatively young. The Mid-Atlantic Ridge stretches across the ocean in the meridional direction, dividing it into western and eastern parts.
The Atlantic Ocean is located in almost all climate zones except the Arctic, but its largest part lies in the areas of equatorial, subequatorial, tropical and subtropical climates. In the temperate latitudes of the Northern Hemisphere, strong westerly winds dominate, but they reach their greatest strength in the temperate latitudes of the Southern Hemisphere. In subtropical and tropical latitudes, trade winds predominate.
In the Atlantic Ocean there are well-defined currents directed almost in the meridional direction. This is due to the large elongation of the ocean from north to south and the outlines of its coastline. The most famous warm current Gulf Stream and its continuation - North Atlantic flow.
The salinity of ocean waters is generally higher medium salinity waters of the World Ocean, and the organic world is poorer in terms of biodiversity in comparison with the Pacific Ocean.
Since ancient times, the Atlantic Ocean began to be developed by people and is now considered the most developed. Important passages across the Atlantic sea routes, connecting Europe with North America and both these parts of the world with oil countries Persian Gulf. The shelves of the North Sea and the Gulf of Mexico are places of oil production. Material from the site
The seas of the Atlantic Ocean are the main fishing areas; up to half of the world's fish catch is caught here. The main fishing areas are shelves, that is, relatively shallow areas of the ocean. Herring fish (herring, sardines), cod (cod, haddock, navaga), mackerel, flounder, halibut, sea bass, eel, sprats, etc. are of commercial importance (Fig. 60). Unfortunately, stocks of Atlantic herring and cod, sea bass and other fish species have sharply decreased. Today, the problem of preserving the biological and mineral resources of not only the Atlantic, but also the rest of the oceans is particularly acute. Fishing countries around the world agree on permissible fish catches and measures to combat poachers.
The Atlantic Ocean, or Atlantic, is the second largest (after the Pacific) and the most developed among other water areas. In the east it is limited by the coasts of South and North America, in the west - Africa and Europe, in the north - Greenland, in the south it merges with the Southern Ocean.
Distinctive features of the Atlantic: a small number of islands, complex bottom topography and a highly indented coastline.
Characteristics of the ocean
Area: 91.66 million sq. km, with 16% of the territory falling on seas and bays.
Volume: 329.66 million sq. km
Salinity: 35‰.
Depth: average - 3736 m, greatest - 8742 m (Puerto Rico Trench).
Temperature: in the very south and north - about 0°C, at the equator - 26-28°C.
Currents: conventionally there are 2 gyres - Northern (currents move clockwise) and Southern (counterclockwise). The gyres are separated by the Equatorial Intertrade Current.
Main currents of the Atlantic Ocean
Warm:
Northern trade wind - begins off the west coast of Africa, crosses the ocean from east to west and meets the Gulf Stream near Cuba.
Gulf Stream- the most powerful current in the world, which carries 140 million cubic meters of water per second (for comparison: all the rivers of the world carry only 1 million cubic meters of water per second). It originates near the coast of the Bahamas, where the Florida and Antilles currents meet. Having united, they give rise to the Gulf Stream, which flows into the Atlantic Ocean through the strait between Cuba and the Florida Peninsula. The current then moves north along the US coast. Approximately off the coast of North Carolina, the Gulf Stream turns east and enters the open ocean. After approximately 1,500 km, it meets the cold Labrador Current, which slightly changes the course of the Gulf Stream and carries it to the northeast. Closer to Europe, the current splits into two branches: Azores and North Atlantic.
Only recently it became known that 2 km below the Gulf Stream there is a reverse current flowing from Greenland to the Sargasso Sea. This flow of icy water was called the Anti-Gulf Stream.
North Atlantic- a continuation of the Gulf Stream, which washes the western coast of Europe and brings the warmth of southern latitudes, providing a mild and warm climate.
Antilles- begins east of the island of Puerto Rico, flows north and joins the Gulf Stream near the Bahamas. Speed - 1-1.9 km/h, water temperature 25-28°C.
Interpass countercurrent - current encircling Earth along the equator. In the Atlantic, it separates the North Trade Wind and South Trade Wind Currents.
South Passat (or South Equatorial) - passes through the southern tropics. average temperature water - 30°C. When the South Trade Wind Current reaches the coast of South America, it divides into two branches: Caribbean, or Guiana (flows north to the coast of Mexico) and Brazilian— moving south along the coast of Brazil.
Guinean - located in the Gulf of Guinea. It flows from west to east and then turns south. Together with the Angolan and South Equatorial currents, it forms the cyclic current of the Gulf of Guinea.
Cold:
Lomonosov countercurrent - discovered by a Soviet expedition in 1959. It originates off the coast of Brazil and moves north. The 200 km wide stream crosses the equator and flows into the Gulf of Guinea.
Canary- flows from north to south, towards the equator along the coast of Africa. This wide stream (up to 1 thousand km) near Madeira and the Canary Islands meets the Azores and Portuguese currents. Approximately around 15°N latitude. joins the Equatorial Countercurrent.
Labrador - begins in the strait between Canada and Greenland. It flows south to the Newfoundland Bank, where it meets the Gulf Stream. The waters of the current carry cold from North Arctic Ocean, and along with the flow, huge icebergs are carried south. In particular, the iceberg that destroyed the famous Titanic was brought precisely by the Labrador Current.
Benguela- is born near the Cape of Good Hope and moves along the coast of Africa to the north.
Falkland (or Malvinas) branches off from the West Wind Current and flows north along the east coast of South America to the Gulf of La Plata. Temperature: 4-15°C.
Current of the westerly winds encircles the globe in the region of 40-50°S. The flow moves from west to east. In the Atlantic it branches off South Atlantic flow.
Underwater world of the Atlantic Ocean
The underwater world of the Atlantic is poorer in diversity than in the Pacific Ocean. This is due to the fact that the Atlantic Ocean was more frozen during ice age. But the Atlantic is richer in the number of individuals of each species.
Flora and fauna underwater world clearly distributed among climatic zones.
The flora is represented mainly by algae and flowering plants (Zostera, Poseidonia, Fucus). IN northern latitudes Laminaria predominates; in temperate areas, red algae predominates. Throughout the ocean, phytoplankton actively thrives at depths of up to 100 m.
The fauna is rich in species. Almost all species and classes of marine animals live in the Atlantic. Of the commercial fish, herring, sardine, and flounder are especially valued. There is an active catch of crustaceans and mollusks, and whaling is limited.
The tropical zone of the Atlantic amazes with its abundance. There are a lot of corals and a lot amazing views animals: turtles, flying fish, several dozen species of sharks.
The name of the ocean first appears in the works of Herodotus (5th century BC), who calls it the Sea of Atlantis. And in the 1st century AD. The Roman scientist Pliny the Elder writes about a vast expanse of water called Oceanus Atlanticus. But official name The “Atlantic Ocean” was established only in the 17th century.
The history of Atlantic exploration can be divided into 4 stages:
1. From antiquity to the 15th century. The first documents that talk about the ocean date back to the 1st millennium BC. The ancient Phoenicians, Egyptians, Cretans and Greeks knew the coastal zones of the water area well. Maps of those times have been preserved with detailed depth measurements and indications of currents.
2. The time of the Great Geographical Discoveries (XV-XVII centuries). The development of the Atlantic continues, the ocean becomes one of the most important trade routes. In 1498, Vasco de Gama, having circumnavigated Africa, paved the way to India. 1493-1501 - Columbus's three voyages to America. The Bermuda anomaly was identified, many currents were discovered, and detailed maps depths, coastal zones, temperatures, bottom topography.
Expeditions of Franklin in 1770, I. Kruzenshtern and Yu. Lisyansky of 1804-06.
3. XIX - first half of the XX century - the beginning of scientific oceanographic research. Chemistry, physics, biology, ocean geology are studied. A map of currents has been compiled, and research is being carried out to lay an underwater cable between Europe and America.
4. 1950s - present day. A comprehensive study of all components of oceanography is being carried out. Priority: climate research different zones, identifying global atmospheric problems, ecology, mining, ensuring ship traffic, seafood production.
In the center of the Belize Barrier Reef there is a unique underwater cave - Big Blue hole. Its depth is 120 meters, and at the very bottom there is a whole gallery of smaller caves connected by tunnels.
The Atlantic is home to the only sea in the world without shores - the Sargasso. Its boundaries are formed by ocean currents.
Here is one of the most mysterious places on the planet: Bermuda Triangle. The Atlantic Ocean is also home to another myth (or reality?) - the continent of Atlantis.
Atlantic ocean map
Ocean area – 91.6 million sq. km;
Maximum depth – Puerto Rico Trench, 8742 m;
Number of seas – 16;
The largest seas are the Sargasso Sea, the Caribbean Sea, the Mediterranean Sea;
The largest gulf is the Gulf of Mexico;
The most large islands– Great Britain, Iceland, Ireland;
The strongest currents:
- warm - Gulf Stream, Brazilian, North Passat, South Passat;
- cold - Bengal, Labrador, Canary, Western Winds.
The Atlantic Ocean occupies the entire space from subarctic latitudes to Antarctica. In the southwest it borders on the Pacific Ocean, in the southeast on the Indian Ocean and in the north on the Arctic Ocean. In the northern hemisphere, the coastline of the continents that are washed by the waters of the Arctic Ocean is greatly indented. There are many inland seas, especially in the east.
The Atlantic Ocean is considered a relatively young ocean. The Mid-Atlantic Ridge, which stretches almost strictly along the meridian, divides the ocean floor into two approximately equal parts. In the north, individual peaks of the ridge rise above the water in the form of volcanic islands, the largest of which is Iceland.
The shelf part of the Atlantic Ocean is not large - 7%. The greatest width of the shelf, 200 – 400 km, is in the area of the North and Baltic seas.
The Atlantic Ocean is found in all climate zones, but most of it is in tropical and temperate latitudes. The climatic conditions here are determined by trade winds and westerly winds. Greatest strength winds reach the temperate latitudes of the South Atlantic Ocean. In the region of the island of Iceland there is a center for the generation of cyclones, which significantly affect the nature of the entire Northern Hemisphere.
Average temperatures surface waters in the Atlantic Ocean is much lower than in the Pacific. This is due to the influence of cold waters and ice that come from the Arctic Ocean and Antarctica. In high latitudes there are many icebergs and drifting ice floes. In the north, icebergs slide from Greenland, and in the south from Antarctica. Nowadays, the movement of icebergs is monitored from space by artificial satellites of the earth.
Currents in the Atlantic Ocean have a meridional direction and are characterized by strong movement activity water masses from one latitude to another.
Organic world Atlantic Ocean species composition poorer than Tikhoy's. This is explained by geological youth and cooler climatic conditions. But despite this, the reserves of fish and other marine animals and plants in the ocean are quite significant. The organic world is richer in temperate latitudes. More favorable conditions for many species of fish to live in the northern and northwestern parts of the ocean, where there are fewer flows of warm and cold currents. Here the following products are of industrial importance: cod, herring, sea bass, mackerel, capelin.
The natural complexes of individual seas and the inflow of the Atlantic Ocean stand out as unique. This is especially true for inland seas: the Mediterranean, Black, Northern and Baltic. In the northern subtropical zone The Sargasso Sea is located, unique in its nature. The giant sargassum algae that the sea is rich in made it famous.
The Atlantic Ocean has important sea routes that connect New World with the countries of Europe and Africa. The Atlantic coast and islands are home to world-famous recreation and tourism areas.
The Atlantic Ocean has been explored since ancient times. Since the 15th century, the Atlantic Ocean has become the main waterway of mankind and does not lose its importance today. The first period of ocean exploration lasted until the middle XVIII century. It was characterized by the study of the distribution of ocean waters and the establishment of ocean boundaries. A comprehensive study of the nature of the Atlantic began with late XIX centuries.
The nature of the ocean is now being studied by more than 40 scientific ships from around the world. Oceanologists carefully study the interaction of the ocean and the atmosphere, observe the Gulf Stream and other currents, and the movement of icebergs. The Atlantic Ocean is no longer able to restore its own biological resources. Preserving its nature today is an international matter.
Choose from one of the unique Atlantic Ocean locations and... Google maps take an exciting journey.
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Atlantic Ocean part of the World Ocean bounded by Europe and Africa to the east and North and South America to the west. The name comes from the name of the Titan Atlas (Atlas) in Greek mythology.
The Atlantic Ocean is second in size only to the Pacific; its area is approximately 91.56 million km 2. The length of the Atlantic Ocean from north to south is about 15 thousand km, the smallest width is about 2830 km (in the equatorial part of the Atlantic Ocean). Average depth 3332 m, average volume water 337541 thousand km 3 (without seas, respectively: 82441.5 thousand km 2, 3926 m and 323 613 thousand km 3). It is distinguished from other oceans by the 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.
Atlantic coast states - 49 countries: Angola, Antigua and Barbuda, Argentina, Bahamas, Barbados, Benin, Brazil, Great Britain, Venezuela, Gabon, Haiti, Guyana, Gambia, Ghana, Guinea, Guinea-Bissau, Grenada, Democratic Republic Congo, Dominica, Dominican Republic, Ireland, Iceland, Spain, Cape Verde, Cameroon, Canada, Ivory Coast, Cuba, Liberia, Mauritania, Morocco, Namibia, Nigeria, Norway, Portugal, Republic of Congo, Sao Tome and Principe , Senegal, Saint Kitts and Nevis, Saint Lucia, Suriname, USA, Sierra Leone, Togo, Trinidad and Tobago, Uruguay, France, Equatorial Guinea, South Africa.
Climate
The climate of the Atlantic Ocean is varied, the predominant part of the ocean area is between 40 degrees N. w. and 40 degrees south. w. located in equatorial, tropical and subtropical climate zones. In the north and south of the ocean, areas of strong cooling and high atmospheric pressure are formed. The circulation of the atmosphere over the ocean causes the action of trade winds, and in temperate latitudes - westerly winds, which often turn into storms. Climate features affect the properties of water masses.
Conventionally, it is carried out along the equator. From an oceanographic point of view, however, the southern part of the ocean should include the equatorial countercurrent, located at 5–8° N latitude. The northern border is usually drawn along the Arctic Circle. In some places this boundary is marked by underwater ridges.
In the Northern Hemisphere, the Atlantic Ocean has a highly indented coastline. Its narrow northern part is connected to the Arctic Ocean by three narrow straits. In the northeast, the 360 km wide Davis Strait connects it to the Baffin Sea, which belongs to the Arctic Ocean. In the central part, between Greenland and Iceland, there is the Denmark Strait, at its narrowest point only 287 km wide. Finally, in the northeast, between Iceland and Norway, there is the Norwegian Sea, approx. 1220 km. In the east, two water areas protruding deeply into the land are separated from the Atlantic Ocean. The more northern of them begins with the North Sea, which to the east passes into the Baltic Sea with the Gulf of Bothnia and the Gulf of Finland. To the south there is a system of inland seas - the Mediterranean and the Black - with a total length of approx. 4000 km.
In the tropical zone in the southwest of the North Atlantic are the Caribbean Sea and the Gulf of Mexico, connected to the ocean by the Strait of Florida. The coast of North America is indented by small bays (Pamlico, Barnegat, Chesapeake, Delaware and Long Island Sound); to the northwest are the Bays of Fundy and St. Lawrence, the Strait of Belle Isle, Hudson Strait and Hudson Bay.
Surface currents in the North Atlantic Ocean move clockwise. The main elements of this large system are the northward warm Gulf Stream, as well as the North Atlantic, Canary and North Trade Wind (Equatorial) Currents. The Gulf Stream follows from the Strait of Florida and Cuba in a northerly direction along the coast of the United States and approximately 40° N latitude. deviates to the northeast, changing its name to the North Atlantic Current. This current is divided into two branches, one of which follows northeast along the coast of Norway and further into the Arctic Ocean. The second branch turns south and further southwest along the coast of Africa, forming the cold Canary Current. This current moves southwest and joins the North Trade Wind Current, which heads west towards the West Indies, where it merges with the Gulf Stream. To the north of the North Trade Wind Current there is an area of stagnant waters, teeming with algae, known as the Sargasso Sea. The cold Labrador Current runs along the North Atlantic coast of North America from north to south, coming from Baffin Bay and the Labrador Sea and cooling the shores of New England.
South Atlantic Ocean
Some experts refer to the Atlantic Ocean in the south all the water space up to the Antarctic ice sheet; others take the southern limit of the Atlantic to be an imaginary line connecting Cape Horn in South America with the Cape of Good Hope in Africa. The coastline in the southern part of the Atlantic Ocean is much less indented than in the northern part; there are also no inland seas through which the influence of the ocean could penetrate deep into the continents of Africa and South America. The only large bay on the African coast is the Gulf of Guinea. On the coast of South America, large bays are also few in number. The southernmost tip of this continent - Tierra del Fuego - has an indented coastline bordered by numerous small islands.
There are no large islands in the southern part of the Atlantic Ocean, but there are isolated isolated islands, such as Fernando de Noronha, Ascension, Sao Paulo, St. Helena, the Tristan da Cunha archipelago, and in the extreme south - Bouvet, South Georgia , South Sandwich, South Orkney, Falkland Islands.
In addition to the Mid-Atlantic Ridge, there are two main submarine mountain ranges in the South Atlantic. The whale ridge extends from the southwestern tip of Angola to the island. Tristan da Cunha, where it joins the Mid-Atlantic. The Rio de Janeiro Ridge stretches from the Tristan da Cunha Islands to the city of Rio de Janeiro and consists of groups of individual underwater hills.
The major current systems in the South Atlantic Ocean move counterclockwise. The South Trade Wind Current is directed to the west. At the protrusion of the eastern coast of Brazil, it splits into two branches: the northern one carries water along the northern coast of South America to the Caribbean, and the southern one, the warm Brazil Current, moves south along the coast of Brazil and joins the Western Winds Current, or Antarctic Current, which heads east , and then to the northeast. Part of this cold current separates and carries its waters north along the African coast, forming the cold Benguela Current; the latter eventually joins the South Trade Wind Current. The warm Guinea Current moves south along the coast of Northwest Africa into the Gulf of Guinea.
Atlantic Ocean Currents
Between the currents of the Atlantic Ocean one should distinguish between permanent and surface ones. The latter are completely flat, shallow, purely surface currents, occurring wherever a continuous, not too weak wind blows. These currents are therefore for the most part very changeable; however, the current, maintained on both sides of the equator by the trade winds, is quite uniform and reaches a speed of 15-18 km per day. But even constant currents, especially if they are weaker, are subject to the influence of continuous winds regarding direction and strength. The main difference between constant currents is equatorial a current crossing the entire width of the A. ocean from E. to W. It begins at approx. near the Guinea Islands and has an initial width of 300-350 km between 1° north. lat. and 2 - 2 ½° south. lat. In the west it gradually expands, so that on the meridian of Cape Palma it already extends between 2° north. lat. (even further north) and 5° south. wide, and approx. 10° west duty. reaches a width of 8° - 9° (800-900 km). A little west of the Ferro meridian, a rather significant branch in the northwestern direction, traced to 20°, in places to 30° north, is separated from the main current. lat. The equatorial current itself near the Brazilian coast in front of Cape San Roc is divided into the Guiana Current (north) and the Brazilian Coastal Current (south). The initial speed of this current is 40-50 km per day, to the southwest. from Cape Palma in summer it sometimes increases to 80-120 km, and even further west, approx. at 10° west latitude, it reaches an average of 60 km, but can rise to 110 km. The temperature of the equatorial current is everywhere several degrees lower than the temperature of the neighboring parts of the sea, and this proves that the water of this current is delivered by polar currents. Challenger's studies showed that the equatorial current does not reach a significant depth, since already at a depth of 100 m the current speed was found to be half that on the surface, and at 150 m depth almost no movement was noticeable at all. Southern branch - Brazilian Current, extends approx. at a distance of 400 km from the coast, has a daily speed of 35 km and, gradually expanding, reaches the mouth of La Plata. Here it is divided: the weaker branch continues in the south almost to Cape Gorna, while the main branch turns to the east and, connecting with the current from the Pacific Ocean, skirting the southern tip of America, forms a large south Atlantic current. This latter accumulates its waters off the southern part of the western coast of Africa, so that only with a southerly wind does the Agulhas current, which goes around the southern tip of the continent, deliver its more warm waters to the north, while with western or northern winds it turns completely to the east. Off the coast of Lower Guiana, a northern current dominates, carrying the accumulating waters back into the equatorial current. The northern branch of this current called Guiana- is directed along the coast of South America at a distance of 20 km from it, reinforced on one side by the northern trade wind current, on the other - the waters of the Amazon River, forming a flow towards the N. and N.W. The speed of the Guiana Current ranges from 36 to 160 km per day. Between Trinidad and Martinique it enters the Caribbean Sea, which it crosses with a gradually decreasing speed in a large arc, generally parallel to the coast, until it flows through the Yucatan Strait into the Gulf of Mexico. Here it divides into two branches: the weaker one along the northern coast of the island of Cuba goes straight to the Strait of Florida, while the main branch describes a large arc parallel to the coast and joins the first branch at the southern tip of Florida. The speed gradually increases to 50-100 km per day. Through the Straits of Florida (Beminin Gorge) it again enters the open ocean called Golfstroma, the ocean dominating the northern part of Africa; Golfstrom's significance extends far beyond the borders of the ocean; he provided greatest influence on the entire development of the latest international relations (see. Golfstrom). Crossing A. ocean approx. at 40° north lat., it is divided into several branches: one goes between Iceland and the Faroe Islands to the northeast; the other has east direction, at Cape Ortegala it enters the Bay of Biscay and then turns to the N. and N.W. called the Rennel Current, having separated from itself a small side branch into the Irish Sea, meanwhile the main current with a reduced speed goes to northern shores Norway and is even spotted off our Murmansk coast. The Rennel Current is dangerous for sailors, as it often drives ships heading to the Pas de Calais towards the cliffs of the Scillian Islands. Two currents emerging from the Arctic Ocean are also of outstanding importance for navigation and climate: one of them (East Greenland) is directed along the eastern coast of Greenland to the south, maintaining this direction for the main mass of its waters up to 50° north. wide, separating only the branch going past Cape Farewell into the Davis Strait; the second current, often unfairly called the Hudson Bay Current, leaves Baffin Bay through Davis Strait and joins the East Greenland Current at New Foundland. Meeting an obstacle there in the Gulf Stream, this current turns west and runs along the coast of the United States to Cape Hatteras and is noticeable even off Florida. Part of the waters of this current apparently passes under the Gulfstrom. Since the water of this current is 10° sometimes even 17° colder than the Gulf Stream, it has a strong cooling effect on the climate of the eastern coast of America. Shipping should especially take this current into account because of the mass of ice it brings from the polar countries. These ice floes have the shape ice mountains, originating from Greenland glaciers, then ice fields torn from ice jams Arctic Ocean. In the area of North Atlantic shipping lines, these floating ice masses appear in March and threaten ships sailing there until August.
Flora and fauna of the Atlantic Ocean
The flora of the Atlantic Ocean is very diverse. Bottom vegetation (phytobenthos), occupying the coastal zone to a depth of 100 m (about 2% of total area ocean floor), includes brown, green and red algae, as well as those living in salt water flowering plants(philospadix, zoster, poseidonia).
Between the bottom vegetation of the northern and southern parts The Atlantic Ocean has similarities, but the leading forms are represented by different species, and sometimes genera. The similarities between the vegetation of the western and eastern coasts are more clearly expressed.
There is a clear geographic change in the main forms of phytobenthos along latitude. In the high Arctic latitudes of the Atlantic Ocean, where the surface is covered with ice for a long time, the littoral zone is devoid of vegetation. The bulk of phytobenthos in the sublittoral zone consists of kelp with an admixture of red algae. In the temperate zone along the American and European coasts of the North Atlantic, it is typical rapid development phytobenthos. Brown algae (fucus and ascophyllum) predominate in the littoral zone. In the sublittoral zone they are replaced by species of kelp, alaria, desmarestia and red algae (furcelaria, ahnfeltia, lithothamnion, rhodomenia, etc.). Zostera is common on soft soils. In the temperate and cold zones of the Southern Hemisphere, brown algae, in particular kelp, predominate. In the tropical zone, in the littoral zone and in the upper horizons of the sublittoral zone, due to strong heating and intense insolation, vegetation is almost absent.
Between 20 and 40° N. w. and 30 and 60° W. in the Atlantic Ocean is located the so-called. The Sargasso Sea, characterized by constant presence floating masses brown algae- sargassum.
Phytoplankton, unlike phytobenthos, develops throughout the entire ocean area in the upper 100-meter layer, but highest concentration reaches in the upper 40-50 m layer.
Phytoplankton consists of small unicellular algae(diatoms, peridines, blue-greens, flint-flagellates, coccolithines). The mass of phytoplankton ranges from 1 to 100 mg/m3, and in high latitudes (50-60°) Northern and Southern hemispheres during the period of mass development (“blooming”) reaches 10 g/m3 or more.
In the cold and temperate zones The northern and southern parts of the Atlantic Ocean are dominated by diatoms, which make up the bulk of phytoplankton. For coastal areas of the North Atlantic, it is typical in spring mass development pheocystis (from golden algae). Widespread in the tropics different kinds coccolithin and blue-green algae Trichodesmium.
The greatest quantitative development of phytoplankton in the high latitudes of the Atlantic Ocean is observed in the summer during the period of the most intense insolation. The temperate region is characterized by two peaks in the development of phytoplankton. Spring “blooming” is characterized by maximum biomass. During the autumn “blooming” the biomass is significantly lower than in the spring. In the tropical region, phytoplankton development occurs all year round, but the biomass throughout the year is small.
The flora of the tropical region of the Atlantic Ocean is characterized by greater qualitative diversity, but less quantitative development than vegetable world temperate and cold zones.
Animal organisms inhabit the entire water column of the Atlantic Ocean. The diversity of fauna increases in the direction of the tropics. In cold and temperate zones it numbers thousands of species, in tropical zones - tens of thousands. For cold and temperate zones Characteristic: 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. At least 100 species of animals are bipolar, that is, they are characteristic of cold and temperate zones and are absent in the tropics. These include seals, fur seals, whales, sprat, sardines, anchovies, and many invertebrates, including mussels. The tropical zones of the Atlantic Ocean are characterized by: sperm whales, sea turtles, crustaceans, sharks, flying fish, crabs, coral polyps, scyphoid jellyfish, siphonophores, radiolarians. The fauna of the Sargasso Sea is unique. Both free-swimming animals (mackerel, flying fish, pipefish, crabs, etc.) and those attached to algae (anemones, bryozoans) live here.
Deep-sea fauna The Atlantic Ocean is richly represented by sponges, corals, echinoderms, crustaceans, fish, etc. This fauna is classified as an independent Atlantic deep-sea region. For information on commercial fish, see the section Fisheries and Marine Fisheries.
Seas and bays
Most of the seas Atlantic Ocean according to physical and geographical conditions, they are Mediterranean - the Baltic, Black, Mediterranean, Caribbean Seas, Gulf of Mexico, etc. and marginal - the North, Gulf of Guinea.
Islands
The largest islands are concentrated in the northern part of the ocean; these are the British Isles, Iceland, Newfoundland, Cuba, Haiti (Hispaniola) and Puerto Rico. On the eastern edge of the Atlantic Ocean there are several groups of small islands - the Azores, Canary Islands, and Cape Verde. Similar groups exist in the western part of the ocean. Examples include the Bahamas, Florida Keys and Lesser Antilles. The Greater and Lesser Antilles archipelagos form an island arc surrounding the eastern Caribbean Sea. In the Pacific Ocean, such island arcs are characteristic of areas of crustal deformation. Deep-sea trenches are located along the convex side of the arc.
There are no large islands in the southern part of the Atlantic Ocean, but there are isolated isolated islands, such as Fernando de Noronha, Ascension, Sao Paulo, St. Helena, the Tristan da Cunha archipelago, and in the extreme south - Bouvet, South Georgia , South Sandwich, South Orkney, Falkland Islands.