The Atlantic Ocean is the second largest and deepest. Its area is 91.7 million km2. The average depth is 3597 m, and the maximum is 8742 m. The length from north to south is 16,000 km.
Geographical location of the Atlantic Ocean
The ocean extends from the North Arctic Ocean in the north to the coast of Antarctica in the south. In the south, the Drake Passage separates the Atlantic Ocean from the Pacific Ocean. Feature Atlantic Ocean - many inland and marginal seas in the Northern Hemisphere, the formation of which is mainly associated with tectonic movements lithospheric plates. (Locate on the map “Building earth's crust» lithospheric plates, within which the ocean is located.) The largest of the seas: Baltic, Black, Azov, Irish, Northern, Sargasso, Norwegian, Mediterranean. There are more than 10 seas in the Atlantic Ocean. (Find on physical map Sargasso and Mediterranean seas, compare their natural features.)
The Atlantic Ocean and its seas wash five continents. On its shores there are more than 70 states (home to over 2 billion people) and 70% largest cities peace. Therefore, the most important sea routes shipping. The ocean is called “the element that unites peoples.”
Bottom relief The Atlantic Ocean, according to scientists, is the youngest and more leveled. The Mid-Atlantic Ridge extends over 18,000 km from north to south of the ocean. Along the ridge there is a rift system where the largest volcanic island, Iceland, was formed. Within the Atlantic Ocean, depths of 3000-6000 m predominate. Unlike the Pacific Ocean, there are few deep-sea trenches in the Atlantic Ocean. The deepest is Puerto Rico (8742 m) in the Caribbean Sea. Within the ocean there is a well-defined shelf zone, especially in the Northern Hemisphere off the coast North America and Europe.
Atlantic Ocean Climate
The ocean is found in almost all geographical zones. This determined the diversity of its climate. In the north, near the island of Iceland, an area of low pressure is formed over the ocean, which is called the Icelandic Low. The dominant winds over the ocean in tropical and subequatorial latitudes are trade winds, and in temperate latitudes they are westerly winds. Differences in atmospheric circulation cause uneven distribution of precipitation. (Refer to the Annual Precipitation map for the distribution of precipitation in the Atlantic Ocean.) average temperature surface waters in the Atlantic Ocean is +16.5 °C. The ocean has the most saline surface waters, its average salinity 35.4 ‰. The salinity of surface waters varies greatly between the north and south.
The maximum salinity reaches 36-37 ‰ and is typical for tropical areas with low annual amount precipitation and strong evaporation. The decrease in salinity in the north and south of the ocean (32-34 ‰) is explained by the melting of icebergs and floating sea ice.
Currents in the Atlantic Ocean act as powerful carriers of thermal energy. Two systems of currents have formed in the ocean: clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere. In tropical latitudes of the ocean, trade winds cause powerful surface currents from east to west on both sides of the equator - the North Trade Wind and South Trade Wind Currents. Crossing the ocean, these currents have a warming effect on the eastern shores of the North and South America. Powerful warm current The Gulf Stream (“Gulf Current”) originates in the Gulf of Mexico and reaches the islands of Novaya Zemlya. The Gulf Stream carries 80 times more water than all rivers globe. The thickness of its flow reaches 700-800 m. This mass warm water with temperatures up to +28 °C it moves at a speed of about 10 km/h. North of 40° N. w. The Gulf Stream turns to the shores of Europe, and here it is called the North Atlantic Current. The water temperature of the current is higher than in the ocean. Therefore, the current is dominated by warmer and more humid air masses and cyclones form. Cooling effect on western shores Africa is influenced by the Canary and Benguela Currents, and the cold Labrador Current influences the east coast of North America. The eastern shores of South America are washed by the warm Brazilian Current.
The ocean is characterized by rhythmically repeating ebbs and flows. Highest height tidal wave in the world reaches 18 m in the Bay of Fundy off the coast.
Natural resources and environmental problems of the Atlantic Ocean
The Atlantic Ocean is rich in diverse mineral resources. The most large deposits oil and gas have been explored in the shelf zone off the coast of Europe (area North Sea), America ( Gulf of Mexico, Maracaibo Lagoon) etc. (Fig. 43). Phosphorite deposits are significant; ferromanganese nodules are less common.
Organic world of the Atlantic Ocean in terms of the number of species it is poorer than the Pacific and Indian Oceans, but is characterized by higher productivity.
The tropical ocean has the greatest diversity organic world, the number of fish species is measured in tens of thousands. These are tuna, mackerel, sardines. In temperate latitudes large quantities There are herring, cod, haddock, and halibut. Jellyfish, squid, octopuses are also inhabitants of the ocean. Large marine mammals (whales, pinnipeds) live in cold waters, different kinds fish (herring, cod), crustaceans. The main fishing areas are the northeast off the coast of Europe and the northwest off the coast of North America. The wealth of the ocean is brown and red algae, kelp.
By degree economic use The Atlantic Ocean ranks first among other oceans. Using the ocean plays big role in the economic development of many countries of the world (Fig. 44).
The expanses of the Atlantic Ocean are most polluted with oil and petroleum products. In modern ways Water purification is carried out, and the discharge of production waste is prohibited.
Features geographical location The Atlantic Ocean is characterized by its great elongation from north to south and the presence of internal and marginal seas. The Atlantic Ocean plays a leading role in the implementation of international economic ties. For five centuries it has occupied first place in world shipping.
Basic questions: What are the features of the geographic location of the Atlantic Ocean? What is its role in the implementation of international economic relations?
The Atlantic Ocean is the second largest and deepest. Its area is 91.6 million km2.
Geographical position. The ocean extends from the Arctic Ocean in the north to the coast of Antarctica in the south. On South Drake Passage connects the Atlantic Ocean with the Pacific. A characteristic feature of the Atlantic Ocean is its many internal and marginal seas. From total area The ocean accounts for approximately 11% of the seas, while in the Pacific - 8%, and in the Indian - only 2%. The presence of internal and marginal seas is mainly associated with tectonic movements. (Show on the map Sargasso, Mediterranean Sea. ). The ocean has the most saline surface waters, its average salinity is 36-37‰. ( Study the salinity of the waters of the Atlantic Ocean using the textbook map).
Relief The Atlantic Ocean, according to scientists, is the youngest and more leveled. Runs along the entire ocean Mid-Atlantic Ridge with a length of more than 18,000 km. A rift system runs along the ridge, where the largest volcanic island on Earth, Iceland, was formed. It can be considered as a “product” of the expansion of the ocean floor. The vast territory of the Atlantic Ocean is dominated by depths of 3000 - 6000 m. Unlike the Pacific Ocean, there are few deep-sea trenches in the Atlantic Ocean. The most famous Puerto Rico(8742 m) in the Caribbean Sea - the greatest depth in the Atlantic Ocean. The shelf is becoming increasingly important for the economic activities of the population of coastal countries.
Currents in the Northern Hemisphere they form two rings. (Study the current system on the map. Show on the map Brazilian, Labrador, Benguela and other currents) The most famous current in the Atlantic Ocean is Gulf Stream(translated as “Gulf Current”) - originates in the Gulf of Mexico. It carries 80 times more water than all the rivers on the globe. The thickness of its flow reaches 700-800 m. This mass of warm water with a temperature of up to 28°C moves at a speed of about 10 km/h. North of 40° N. w. The Gulf Stream turns to the shores of Europe and here it is called North Atlantic Current. The water temperature of the current is higher than in the ocean. Therefore, warmer and more humid air masses dominate over the current and form cyclones. The ocean is characterized by rhythmically repeating tides And low tides. The highest tidal wave in the world reaches 18 m in the bay Fundy off the coast of Canada . (Fig. 1) (Show on map Brazilian and Benguela currents)
Climate. The elongation of the Atlantic Ocean from north to south determined the diversity of its climate . It is located in all climatic zones. In the north, near the island of Iceland, an area of low pressure is formed above the ocean, which is called the Icelandic minimum. The island of Iceland is the center of cyclone formation. Prevailing winds over the ocean in tropical and subequatorial latitudes - trade winds, in moderate - westerly winds. Differences in atmospheric circulation cause uneven distribution of precipitation (study "Annual precipitation" map). The average surface water temperature in the Atlantic Ocean is +16.5°C. Salinity indicators of surface waters are varied compared to other oceans. The maximum salinity of 36-37‰ is typical for tropical areas with low annual precipitation and strong evaporation. The decrease in salinity in high latitudes (32-34‰) is explained by the melting of icebergs and floating sea ice.
Natural resources And ecological problems . The Atlantic Ocean is rich in a variety of mineral resources. The largest oil and gas deposits have been explored in the shelf zone off the coast of Europe (North Sea region) (Figure 2,3,4), America (Gulf of Mexico, Maracaibo Lagoon), etc. Phosphorite deposits are significant, but ferromanganese nodules are much less common.
Organic world in terms of species, it is poorer than in the Pacific and Indian, but the richest in quantitative terms. The ocean is the youngest and has been isolated from other oceans for a long time. IN tropical part the greatest diversity of the organic world, the number of fish species is measured in tens of thousands. These are tuna, mackerel, sardines. IN temperate latitudes– herring, cod, haddock, halibut. Jellyfish, squid, and octopuses are also inhabitants of the ocean. IN cold waters large marine mammals live whales, pinnipeds), various types of fish ( herring, cod), crustaceans. The main fishing areas are northeastern off the coast of Europe and northwestern off the coast of North America. The wealth of the ocean is brown and red algae, kelp.
In terms of economic use, the Atlantic Ocean ranks first among other oceans. The use of the ocean plays a major role in the economic development of many countries. The ocean is called “the element that unites peoples.” There are more than 90 coastal states on the shores of four continents facing the ocean. They are home to over 2 billion people. 70% of the world's largest cities are located on its shores.
The expanses of the Atlantic Ocean are most polluted with oil and petroleum products. Modern methods are used to purify water, and the discharge of production waste is prohibited.
The importance of the Atlantic Ocean in the implementation ofinternational economic relations. INFor five centuries it has occupied first place in world shipping. The ocean is located in the “habitat center” of the peoples of various countries, which determine the development of the economy and culture of the world.
1.Practical work. Apply to contour map large seas, bays, straits in the Atlantic Ocean. *2. Determine the influence of the North Atlantic Current on the nature of the European coast. 3. Show countries on the map and big cities on the Atlantic coast. **4. Using an analysis of the textbook map, determine the importance of oil fields in the North Sea basin for European countries?
The Atlantic Ocean is limited in the west by the shores of North and South America, in the east by the shores of Europe and Africa to Cape Agulhas. Northern border with the Arctic Ocean runs along the parallel of 70 ° N. sh., east of Cape Brewster to Iceland, further to the Faroe and Shetland Islands at 61 ° N. w. to the shores of Norway.
The ocean area is 91.6 million km2, the average depth is 3,600 m. In the Puerto Rico Trench, the depths of the Atlantic Ocean reach maximum values of 8,742 m. Important feature ocean is the presence Mediterranean seas(Mediterranean Sea, Gulf of Mexico and Caribbean Sea). Most of islands of the Atlantic Ocean are of continental origin, but there are also volcanic and coral islands. The shelf occupies about 10% of the ocean floor area. The continental slope is steep, cut by underwater canyons (the largest is the Hudson). The relief of the Atlantic Ocean bed is dominated by underwater ridges, rises and basins. Almost in the middle of the ocean, the Mid-Atlantic Ridge stretches for 18,000 km. Its ridge is cut through a system rift valleys, and the spine itself is crossed by latitudinal faults.
Climate and water
The Atlantic Ocean lies in all climate zones except the subarctic, arctic and antarctic. Strong westerly winds prevail in temperate latitudes, and northeast and southeast trade winds prevail in subtropical and tropical latitudes. Temperate latitude winds are strong Southern Hemisphere(“Roaring Forties”) IN northern latitudes Tropical or West Indian hurricanes often sweep through.
Trade winds from tropical latitudes cause powerful North and South trade wind currents. Northern Trade wind current bifurcates at the Lesser Antilles: the Antilles Current moves along the shores of the Greater Antilles; southern industry pours into the Caribbean; combined with the Guiana Current, it flows into the Gulf of Mexico, raising the water level there. This causes the formation of the Florida Current, merging with the Antilles Current, forming known current Gulf Stream. The Northern Cyclonic Gyre consists of currents - the warm North Atlantic and Irminger and the cold Labrador.
Surface water temperatures vary from 26-28°C at the equator to 6-10°C at 60°N. w. and 0-1°C at 60°S. w. The salinity of water in the Atlantic Ocean ranges from 34 to 37 ‰.
It is carried from the Arctic Ocean to the Atlantic a large number of ice and icebergs. In the southern part of the ocean, ice and icebergs form off the coast of Antarctica.
The total number of fish species exceeds 15 thousand. In Antarctic waters, notothenia predominate among fish; benthic organisms and plankton are poor. In the tropics, bottom vegetation consists mainly of green and red algae. The most characteristic representatives tropical zone- siphonophores, jellyfish, crabs, flying fish, sharks, sea turtles, sperm whales, large cephalopods - squid, including bottom forms - octopuses. Mackerel, tuna, sardines, and anchovies are of industrial importance. Corals are common in tropical and subtropical regions. The deep-sea fauna is rich in crustaceans, echinoderms, and sponges.
Temperate latitudes are characterized by abundant life with a relatively small diversity of fauna. Copepods and pteropods, herring, cod and flounder fish, whales, pinnipeds, etc. are common here. Among the commercial fish highest value have herring, cod, haddock, halibut, sea bass. There are few seabirds. Frigates, albatrosses, penguins, etc. live off the coast of Antarctica.