Organic world of the Atlantic Ocean: features and description. Which parts of the Atlantic Ocean are particularly polluted and why? How the natural complex changes in the Atlantic Ocean
Detailed solution to paragraph § 16 on geography for 7th grade students, authors Korinskaya V.A., Dushina I.V., Shchenev V.A. 2017
Questions and assignments.
1. What influence does its geographical location and size have on the nature of the Atlantic Ocean?
A gigantic mountain range stretches across the entire Atlantic. In one place it comes to the surface - this is the island of Iceland. The ridge divides the ocean floor into two almost equal parts. Vast shelves adjoin the coasts of Europe and North America. The Atlantic Ocean lies in all climate zones. The widest part of the ocean lies in tropical and temperate latitudes. Trade winds and westerly winds of temperate latitudes blow in these latitudes. In winter, storms often occur in temperate latitudes; in the Southern Hemisphere, they rage in all seasons of the year. Surface water temperatures are lower than those in the Pacific and Indian Oceans. This is explained by the cooling influence of water and ice carried out from the Arctic Ocean and Antarctica, as well as intense mixing of water masses. Noticeable differences between water and air temperatures in several areas of the Atlantic cause the formation of strong fogs. The salinity of water masses in some areas of the ocean is higher than average, since a significant part of the evaporated moisture, due to the relative narrowness of the ocean, is transported by winds to neighboring continents. Currents in the Atlantic have a meridional rather than latitudinal direction. The reasons for this are the large elongation of the ocean from north to south and the outline of the coastline. Currents in the Atlantic more actively transport input masses, and with them heat and cold, from one latitude to another. The ocean is characterized by numerous icebergs and floating sea ice.
2. Identify natural complexes in the Atlantic Ocean in which latitudinal zoning is manifested, and complexes formed under the influence of land. Explain their features.
The Atlantic Ocean has almost all natural zones. Within them there are natural complexes of seas and bays (Mediterranean, Northern, Baltic and other seas). By their nature they differ from the complexes of the open ocean. In the northern subtropical zone there is the Sargasso Sea, unique in its nature - a sea without shores. Its boundaries are formed by currents. The waters of this sea have high salinity (up to 37%) and temperature.
3. Write a description of the nature of the Mediterranean Sea.
The land adjacent to the shores of the Mediterranean Sea in Eurasia and Africa is distinguished by the unity of natural and cultural landscapes. This uniformity of nature and conditions of economic activity around one of the largest seas on Earth was noted by geographers a very long time ago and gave rise to the introduction of the geographical concept of “Mediterranean”, or “Middle-earth”. The peculiarities and originality of the natural conditions of the Mediterranean are determined primarily by the subtropical climate with dry summers and wet winters. Nowhere else on Earth is this type of climate so widespread and so pronounced as on the shores of the Mediterranean Sea, which is why it is called Mediterranean. Climate features determine the uniqueness of the entire natural complex. They determine the nature of runoff and hydrological conditions, the course of soil-forming processes and the formation of a special genetic type of brown soils. A special type of vegetation with clear features of adaptation to summer dryness is also associated with the Mediterranean climate. The Mediterranean Sea cuts into the land between the continents of Europe, Africa and Asia. In the northeast, the Mediterranean Sea is connected by the Dardanelles Strait with the waters of the Sea of Marmara, then through the Bosphorus Strait with the Black Sea. In the southeast it connects to the Red Sea through the Suez Canal. The total area of the Mediterranean Sea is 2.5 million square kilometers, the volume of water is 3.8 million cubic meters. km. The Mediterranean Sea has an average depth of 1,541 meters, and the deepest point is at 5,121 meters. The coastline of the Mediterranean Sea is mainly leveled on mountainous shores, and on low shores it is of the lagoon-estuary type. The largest bays of the Mediterranean Sea: Taranto, Lyon, Valencia, Genoa, Sidra and Gabes. The largest islands: Sicily, Corsica, Balearic Islands, Sardinia, Crete and Cyprus. Large rivers flow into the Mediterranean Sea: Tiber, Nile, Ebro, Po and Rhone. The total annual flow is approximately 430 cubic kilometers. The Mediterranean Sea has very little phyto- and zooplankton, but a lot of algae, such as peridinea and diatoms. The waters are home to approximately 550 species of fish, including herring, anchovy, mackerel, tuna, mullet, coryphen, bonito and horse mackerel.
4. Which parts of the Atlantic Ocean are the most polluted? Tell me why?
The Atlantic Ocean shelves are rich in oil deposits and other minerals. Thousands of wells have been drilled offshore the Gulf of Mexico and the North Sea. Due to the growth of cities, the development of shipping in many seas and in the ocean itself, a deterioration in natural conditions has recently been observed. The waters and air are polluted, and conditions for recreation on the shores of the ocean and its seas have deteriorated. For example, the North Sea is covered with many kilometers of oil slicks. Off the coast of North America, the oil film is hundreds of kilometers wide. The Mediterranean Sea is one of the most polluted on Earth. The Atlantic is no longer able to clean itself of waste on its own. The fight against pollution in this ocean is an international matter. Treaties have already been concluded that prohibit the dumping of hazardous waste into the ocean.
5. What role does the Atlantic Ocean play in the life of humanity?
Of all the oceans, the Atlantic occupies the most important place in the life of mankind. This happened historically. The most important sea routes pass through the Atlantic. Since time immemorial, the Atlantic Ocean has been a place of intensive fishing and hunting. Whaling in the Bay of Biscay was carried out as early as the 9th–12th centuries. The natural conditions of the Atlantic are favorable for the development of life, therefore it is the most productive of all the oceans. Most of the fish catch and production of other marine products comes from northern part ocean. The Atlantic Ocean shelves are rich in oil and other mineral deposits. Thousands of wells have been drilled offshore the Gulf of Mexico and the North Sea.
6. What is unique about the geographic location of the Arctic Ocean? How does it affect his nature?
The Arctic Ocean is the smallest of the Earth's oceans. It is the shallowest. The ocean is located in the center of the Arctic, which occupies the entire space around the North Pole, including the ocean, adjacent parts of the continents, islands and archipelagos. A significant part of the ocean area is made up of seas, most of which are marginal and only one is internal. There are many islands in the ocean located near the continents. The ocean is surrounded by land on almost all sides, which determines the features of its nature - climate, hydrological regime. The boundaries of the Arctic Ocean run from the Scandinavian Peninsula (62° N), to the Shetland and Faroe Islands, along the Danish, Davis and Bering Channels, through which its waters connect with the waters of the Atlantic and Pacific Oceans.
The ocean coastline is highly dissected; It contains nine seas, which account for half of the total ocean surface. Many separate islands and archipelagos (Greenland, Spitsbergen, Franz Josef Land, Novaya Zemlya).
8. How can we explain that the air over the Arctic Ocean is warmer than over Antarctica?
Although Antarctica receives about 7% more solar heat in the summer than the Arctic, the Arctic's climate is significantly warmer than the South Polar region. There are several reasons to explain this seemingly strange phenomenon. One of them is the free communication of the Arctic Ocean with the Atlantic Ocean in the vast area between Greenland and the northern tip of Europe. The warm waters of the Atlantic, including the powerful Gulf Stream, freely penetrating under the Arctic ice, transfer a colossal amount of heat to the Arctic, thereby significantly softening its climate. In addition, together with the fresh water of the largest rivers of Eurasia and North America flowing into the Arctic Ocean, the Arctic receives an additional amount of heat all year round, which the Antarctic is deprived of. But, perhaps, one of the main reasons for the Antarctic cold is that the continent that exists at the South Pole is the highest of all six on Earth. The average height of the Antarctic continent is more than 2,000 m, while the next highest Eurasia has an average height of only about 900 m. This fact is explained by the fact that the continental rocks of Antarctica are covered with a thick layer of ice, the average thickness of which is approximately 1,800 m. Then how in the Central Arctic the height of the surface of the ice fields of the Arctic Ocean is a few meters, which practically corresponds to sea level. Due to the difference in altitude alone, Antarctica should be colder than the Arctic by an average of about 13°C, and at the top of the ice dome - by as much as 25–28°C, since the air temperature in the atmosphere decreases by 6.5°C with every kilometer of altitude.
9. What natural complexes are distinguished in the Arctic Ocean? Why?
The Arctic Ocean is located within the northern Arctic natural zone of the World Ocean. The seas of the ocean lie in the northern subpolar zone. 1. The Northern Polar Belt is a unique water complex. During the year, most of the surface is covered with drifting ice. Wind, currents and tides cause ice to move, and piles of ice are formed - hummocks up to 10–12 m high. This belt is not very suitable for life. Only seals live on its outskirts , walruses, polar bears. 2. The subarctic zone covers parts of the ocean adjacent to the land; their nature is not so harsh. In summer, the water off the coast is free of ice, and is also very desalinated by river waters. In the water areas where warm waters penetrate, there is a lot of plankton and fish.
10. Identify the main types of economic activity in the Atlantic and Arctic oceans.
The Atlantic Ocean represents all types of human economic activity in marine areas. Among them highest value have maritime transport, then - underwater oil and gas production, and only then - fishing and use of biological resources. On the shores of the Atlantic there are more than 70 coastal countries with a population of over 1.3 billion people. Many transoceanic routes with large volumes of freight and passenger traffic pass through the ocean. The most significant ports in the world in terms of cargo turnover are located on the coasts of the ocean and its seas. The already explored mineral resources of the ocean are significant (examples are given above). However, oil and gas fields are currently being intensively developed on the shelf of the North and Caribbean Seas, in the Bay of Biscay. Many countries that previously did not have significant reserves of these types of mineral raw materials are now experiencing economic growth due to their production (England, Norway, the Netherlands, Mexico, etc.).
The biological resources of the ocean have been intensively used for a long time. However, due to overfishing of a number of valuable commercial fish species, recent years The Atlantic is inferior to the Pacific Ocean in terms of fish and seafood production. Intensive human economic activity in the Atlantic Ocean and its seas causes a noticeable deterioration of the natural environment - both in the ocean (water and air pollution, reduction in stocks of commercial fish species) and on the coasts. In particular, recreational conditions on the ocean shores are deteriorating. In order to prevent further and reduce existing pollution of the natural environment of the Atlantic Ocean, scientific recommendations are being developed and international agreements are being concluded on the rational use of ocean resources.
The Arctic Ocean is of exceptional importance for the countries whose shores are washed by its waters. The harsh nature of the ocean makes it difficult to search for minerals. But oil and natural gas deposits have already been explored on the shelf of the Kara and Barents seas, off the coast of Alaska and Canada. The biological wealth of the ocean is small. In the Atlantic region they fish and obtain seaweed, and hunt seals. Whale production in the ocean is strictly limited. The development of the Northern Sea Route began only in the 30s. XX century The Northern Sea Route (abbreviated NSR) is the main shipping route in the Arctic, which significantly reduces the distances between European and Far Eastern ports. The NSR plays a huge role in the development of Siberia. Equipment and food are transported to Siberia along this route, and timber and ore are exported. Navigation lasts from 2 to 4 months, and in some areas with the help of icebreakers its duration is longer. To ensure the operation of the Northern Sea Route, special services have been created in our country: polar aviation, a whole network of meteorological stations on the coast and on drifting ice floes.
11. What professions should polar explorers have?
The Arctic Ocean is studied by people who are called by the expressive word “polar explorers”. Belonging to a polar explorer is determined not only by profession, but also by geographic area of activity. Despite the fact that a person is armed with powerful technology, working in the Arctic Ocean is difficult and dangerous. Polar explorers are characterized not only by courage and courage, endurance and hard work, but also by high professional skills. Geographer, meteorologist, doctor.
The Atlantic Ocean stretches from north to south for 16 thousand km from subarctic to Antarctic latitudes. The ocean is wide in the northern and southern parts, narrowing in equatorial latitudes to 2900 km. In the north it communicates with the Arctic Ocean, and in the south it is widely connected with the Pacific and Indian Oceans. It is limited by the shores of North and South America in the west, Europe and Africa in the east, and Antarctica in the south.
The Atlantic Ocean is the second largest among the planet's oceans. The ocean coastline in the northern hemisphere is heavily dissected by numerous peninsulas and bays. There are many islands, internal and marginal seas near the continents. The Atlantic includes 13 seas, which occupy 11% of its area.
Geographical location of the Atlantic Ocean Wikipedia
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Name the objects of geographical location Atlantic Ocean Cape Galinas Guiana Current Mount Aconcagua 5. Lake Titicaca 6.
Amazon River 7. Orinoco River 8. La Plata Bay 9. Cape Horn.
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In the Atlantic Ocean, all zonal complexes are distinguished - natural zones, except for the North Polar. The waters of the northern subpolar zone are rich in life. It is especially developed on the shelves off the coasts of Iceland, Greenland and the Labrador Peninsula. The temperate zone is characterized by intense interaction between cold and warm waters; its waters are the most productive areas of the Atlantic. Vast areas of warm waters of two subtropical, two tropical and equatorial zones are less productive than the waters of the northern temperate zone.
In the northern subtropical zone, a special natural aquatic complex of the Sargasso Sea stands out.
It is characterized by high water salinity (up to 37.5 ppm) and low bioproductivity. In the clear, pure blue water, brown algae grow - sargassum, which gives the name to the water area.
In the temperate zone of the southern hemisphere, as in the northern, natural complexes are rich in life in areas where waters with different temperatures and water densities mix. The sub-Antarctic and Antarctic belts are characterized by seasonal and permanent ice phenomena, which affect the composition of the fauna (krill, cetaceans, nototheniid fish).
Natural complexes of the Atlantic Ocean Wikipedia
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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? north 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 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, 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 Strait of Gibraltar, which connects the ocean with the Mediterranean Sea, there are two oppositely directed currents, one below the other. The current moving from the Mediterranean Sea to the Atlantic Ocean occupies a lower position, 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 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.
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 archipelagos of the Greater and Lesser Antilles form an island arc surrounding eastern part Caribbean Sea. In the Pacific Ocean, such island arcs are characteristic of deformation areas 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 a depth of about 60 m to several kilometers, is covered with thin, silty sediments of a dark blue or bluish-green 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.
In the central part of the Atlantic Ocean, almost repeating the contours of the coastlines, there is a huge underwater mountain range approx. 16 thousand km, known as the Mid-Atlantic Ridge. This ridge divides the ocean into two approximately equal parts. Most of the peaks of this underwater ridge do not reach the ocean surface and are located at a depth of at least 1.5 km. Some of the highest peaks rise above ocean level and form the islands - the Azores in the North Atlantic and Tristan da Cunha - in the South. In the south, the ridge skirts the coast of Africa and continues further north into the Indian Ocean.
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 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 the island. Cuba north along the US coast and approximately 40? north 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 it that the climate of Norway and all of northwestern Europe is much warmer than would be expected at latitudes corresponding to the area stretching from Nova Scotia to southern Greenland. 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
Borders and coastline. 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.
Bottom relief. 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.
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.
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 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 (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 current, carrying 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, through the Strait of Florida enters the ocean called the Gulf Stream (“stream from the gulf”). This is how the greatest system of warm surface currents in the World Ocean originates 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. 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 stream north of British Isles reaches 185 km, depth - 500 m, current 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, salinity decreases to 32-34% o, especially in summer time, is explained by the melting of icebergs and floating sea ice.
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The second largest Atlantic Ocean is located mostly in the Western Hemisphere and is limited by the shores of North and South America, Europe, Africa and Antarctica. Its border with the Indian Ocean is conditionally drawn along the meridian of Cape Agulhas (about 20° east). The ocean coastline in the northern hemisphere is heavily dissected by peninsulas and bays; in the southern hemisphere, the shores are slightly indented. Important Feature ocean - the presence of Mediterranean seas extending thousands of kilometers deep into the continents (Gulf of Mexico, Caribbean and Mediterranean seas). There are 13 seas in the ocean; they occupy 11% of its area.
Bottom relief
A narrow continental shelf stretches along the coast, but the shelf area of the Atlantic Ocean is larger than that of the Pacific Ocean. The continental slope is steep, indented by submarine canyons. The Mid-Atlantic Ridge stretches across the entire ocean almost in the middle, cut by transverse faults into separate segments. The height of the ridge is 2 km. In its axial part there is a deep rift valley, to which the active volcanoes. On both sides of the ridge there are basins with a relatively flat bottom, separated by uplifts.
Mineral Resources
The North Sea shelf, in the Venezuelan, Mexican, Guinea and Biscay bays are rich in oil. Phosphorite deposits were discovered in the area of rising deep waters off the tropical coast of North Africa. Placer tin was discovered near the coasts of Great Britain and Florida, and diamonds were discovered off the coast of South-West Africa. Reserves of ferromanganese nodules have been found off the coast of Newfoundland and Florida. Sulfur is being mined in the Gulf of Mexico.
Climate
The Atlantic Ocean is located in all climate zones of the Earth.
Over the ocean, 4 main centers of atmospheric action are formed - the Icelandic and Antarctic lows, the North Atlantic and South Atlantic highs, with which westerly winds of moderate latitudes are associated (the strongest in the Southern Hemisphere - the “roaring forties”). The northern tropical hurricanes are characterized by the so-called West Indian hurricanes. Numerous icebergs and floating sea ice from the Arctic Ocean and off the coast of Antarctica - distinguishing feature ocean
Currents
Due to the strong elongation of the Atlantic Ocean from north to south, meridional water flows are more developed in it than latitudinal ones. In the Atlantic, as in the Pacific, two rings of surface currents are formed, but meridional currents predominate here. In the Northern Hemisphere, the warm Northern Trade Wind, Gulf Stream, North Atlantic and cold Canary Currents form a clockwise movement of water. In the Southern Hemisphere, the warm Southern Trade Wind, Brazilian and cold currents of the Western Winds and Benguela rotate the waters counterclockwise.
Currents have a significant influence on the temperature distribution of surface waters. The northern half of the ocean is warmer than the southern half and the temperature difference reaches 6 °C.
The average temperature of surface waters is slightly lower (16.5 °C) than in the Pacific Ocean. The cooling effect is exerted by the waters and ice of the Arctic Ocean and Antarctica. Due to the relative narrowness of the ocean, a significant part of the evaporated moisture is transferred to neighboring continents, so the salinity of surface waters in the Atlantic Ocean is high.
Organic world
The Atlantic Ocean is poorer in species of organisms than the Pacific Ocean (only 200 thousand species of plants and animals). However, its productivity is extremely high. The organic world of tropical regions is more diverse, but the temperate zone regions are distinguished by the number of organisms (not species) and biomass. A significant mass of plankton consists of crustaceans, among them krill, the main food product of baleen whales, is especially abundant off the coast of Antarctica. In the tropical zone, bottom vegetation consists of green and red algae; in extratropical areas, brown algae predominate in the northern part and red algae in the southern part. The Atlantic Ocean produces 2/5 of the world's fish catch (herring, hake, sea bass, tuna, cod).
Natural complexes
In the Atlantic Ocean, all natural zones are distinguished, except for the North Polar. The waters of the northern subpolar zone are rich in life. It is especially developed on the shelves off the coast of Greenland and Labrador. The temperate zone is characterized by intense interaction between cold and warm waters, and they are also rich in organisms. These are the most fishy areas of the Atlantic. Vast areas of warm waters of two subtropical, two tropical and equatorial zones are less productive than the waters of the northern temperate zone. In the northern subtropical zone, a special natural aquatic complex of the Sargasso Sea stands out. It is characterized by high water salinity - up to 37.5 ‰ and low productivity. The water is clear, pure blue. Brown algae, Sargassum, which gives the name to the water area, grows in it.
In the temperate zone of the Southern Hemisphere, there are (as in the northern) complexes where waters of different temperatures and densities mix. These areas are rich in life. The complexes of the subantarctic and antarctic belts are characterized by seasonal ice phenomena.
Lecture added 03/07/2014 at 14:34:40
1.) Between what continents is the ocean located, what other oceans is it connected to,
2.) How is the ocean located relative to the equator, tropics, polar circles, prime median
3.In all climate zones
2. The Atlantic Ocean is divided into northern and southern parts, the border between which is conventionally drawn along the equator.
2) The Atlantic Ocean crosses the equator, the northern and southern tropics, crosses a little, the northern circle, the southern circle (if you don’t take into account the southern ocean because some teachers don’t take it into account), it is intersected by the zero meridian
3) located in all climatic zones except the Arctic, Antarctic and sub-Antarctic in the south (again, excluding the Southern Ocean)
Both tropics cross the ocean
The northern border is usually drawn along the Arctic Circle.
Bordered by the Arctic Ocean along the Antarctic Circle
From the prime meridian - in the west.
1) The Atlantic Ocean is located between Eurasia, America, South America, Africa and from the south touches Antarctica.The Atlantic Ocean is connected to all oceans Pacific (west), Indian (east), southern (south) and northern ice (north) oceans
1.North America, South America, Africa, Eurasia
The Atlantic and Pacific, Indian and Arctic oceans, as well as continental bodies of water, make up the World Ocean. The hydrosphere plays a critical role in shaping the planet's climate. Under the influence of solar energy, part of the water in the oceans evaporates and falls as precipitation on the continents. The circulation of surface water moistens the continental climate and brings heat or cold to the mainland. Ocean water changes its temperature more slowly and therefore differs from the temperature regime of the earth. It should be noted that the climatic zones of the World Ocean are the same as on land.
Climate zones of the Atlantic Ocean
The Atlantic Ocean has a large extent and four atmospheric centers with different air masses - warm and cold - are formed in it. The water temperature regime is affected by water exchange with the Mediterranean Sea, Antarctic seas and the Arctic Ocean. All the climatic zones of the planet pass through the Atlantic Ocean, so different parts The ocean has completely different weather conditions.
Climatic zones of the Indian Ocean
The Indian Ocean is located in four climatic zones. In the northern part of the ocean there is a monsoon climate, which was formed under the influence of the continental one. The warm tropical zone has high air temperatures. Sometimes there are storms with strong winds, and even tropical hurricanes occur. The greatest amount of precipitation falls in the equatorial zone. It can be cloudy here, especially in the area close to Antarctic waters. Clear and favorable weather occurs in the Arabian Sea region.
Climate zones of the Pacific Ocean
The climate of the Pacific Ocean is influenced by the weather of the Asian continent. Solar energy is distributed zonally. The ocean is located in almost all climatic zones except the Arctic. Depending on the belt, in different areas there is a difference in atmospheric pressure, and different air flows circulate. In winter, strong winds predominate, and in summer, southern and weak winds. In the equatorial zone, calm weather almost always prevails. Warmer temperatures in the western part of the Pacific Ocean, cooler in the east.
Source: ECOportal.info
In the Atlantic Ocean, all zonal complexes are distinguished - natural zones, except for the North Polar. The waters of the northern subpolar zone are rich in life. It is especially developed on the shelves off the coasts of Iceland, Greenland and the Labrador Peninsula. The temperate zone is characterized by intense interaction between cold and warm waters; its waters are the most productive areas of the Atlantic. Vast areas of warm waters of two subtropical, two tropical and equatorial zones are less productive than the waters of the northern temperate zone.
In the northern subtropical zone, a special natural aquatic complex of the Sargasso Sea stands out. It is characterized by high water salinity (up to 37.5 ppm) and low bioproductivity. In the clear, pure blue water, brown algae grow - sargassum, which gives the name to the water area.
In the temperate zone of the southern hemisphere, as in the northern, natural complexes are rich in life in areas where waters with different temperatures and water densities mix. The sub-Antarctic and Antarctic belts are characterized by seasonal and permanent ice phenomena, which affect the composition of the fauna (krill, cetaceans, nototheniid fish).
Natural complexes of the Atlantic Ocean Wikipedia
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Atlantic Ocean: !.Surface currents in the ocean.2.Organic world.3. Zonal natural complexes (natural zones) and azonal aquatic complexes of the ocean.
Answers:
1) The Gulf Stream is a warm current of the Atlantic Ocean, it softens the climate of Europe 2) The organic world of the Atlantic Ocean The organic world of the Atlantic Ocean is inferior in the number of species to the Pacific and Indian. This is due to its youth, long-term isolation from the Indian and Pacific oceans, and the strong influence of the cold climate in the Quaternary period.
The phytobenthos of the northern part of the ocean is represented by brown algae (mainly mucoids, kelp, alaria), green, red and brown (Sargasso) algae are common in the tropical zone, and kelp is most common in the southern part of the ocean. Zoobenthos: octopuses, coral polyps, crustaceans, echinoderms, sponges, specific types of fish. 3) In the Atlantic Ocean, all zonal complexes are distinguished - natural zones, except for the North Polar.
The waters of the northern subpolar zone are rich in life. It is especially developed on the shelves off the coasts of Iceland, Greenland and the Labrador Peninsula. The temperate zone is characterized by intense interaction between cold and warm waters; its waters are the most productive areas of the Atlantic. Vast areas of warm waters of two subtropical, two tropical and equatorial zones are less productive than the waters of the northern temperate zone.
In the northern subtropical zone, a special natural aquatic complex of the Sargasso Sea stands out. It is characterized by high water salinity (up to 37.5 ppm) and low bioproductivity.
In the clear, pure blue water, brown algae grow - sargassum, which gives the name to the water area. In the temperate zone of the southern hemisphere, as in the northern, natural complexes are rich in life in areas where waters with different temperatures and water densities mix.
The sub-Antarctic and Antarctic belts are characterized by seasonal and permanent ice phenomena, which affect the composition of the fauna (krill, cetaceans, notothenium FISH
Within the Atlantic Ocean, all physiographic zones are clearly represented, except for the North Polar.
The northern subpolar (subarctic) belt covers the waters off the island of Greenland and the Labrador Peninsula.
In winter, the air temperature drops to - 20°, water temperature to - 1 °C and below. The ocean is partially covered with ice in winter. Ice formation causes an additional increase in the salinity of water and its immersion to depth. In spring and summer, the waters of the belt receive a lot of solar radiation, the ice melts rapidly, the surface layer is desalinated, its temperature reaches + 6 ° C.
A subpolar cyclonic water cycle is formed in the northern subpolar belt.
IN central parts zone, divergence and rise of waters occur. In summer, as a result of heating the surface layer, a subsurface layer of temperature jump is formed. That's why deep mixing stops. Abundant solar radiation causes powerful photosynthetic activity and massive development of phytoplankton in water containing many nutrients.
The water turns green - comes hydrobiological spring. With intensive development of zooplankton begins hydrobiological summer.
The northern temperate zone occupies extensive the water area between North America and Europe, including several seas, bays and straits. It is narrow near North America, where warm and cold currents come together, and wide in the east, where the jets of the North Atlantic Current diverge widely. This zone, like all temperate zones of the World Ocean, is characterized by maximum horizontal temperature gradients and small fluctuations throughout the year, which is associated with the entry into the temperate zones of air and water masses of different origins - tropical and arctic.
Such contrasts are especially noticeable on the western margins of the oceans.
The northern temperate zone is characterized by the dominance of westerly winds. Air masses of tropical and polar origin meet here and are separated by the polar front. A similar phenomenon is observed in the ocean; tropical and high-latitude water masses interact and partially mix.
In the belt located The North, Irish, Celtic Seas, the true subtropical zone is located approximately between 25 and 40 ° N.
w. This is a zone of dominance of high atmospheric pressure and downward movement of air (how many hundreds of meters per day), incoming With antipassat from the equatorial belt.
Air masses of temperate latitudes penetrate into the northern part of the belt in winter, V southern summer - equatorial air.
The state of the atmosphere is usually stable, rain is rare. Over warm water warm, relatively dry tropical air. From here, the air moves to moderate latitudes (southwest wind) and southwest, towards the equator, giving rise to the northeast trade wind.
The southern strip of the subtropical belt is the zone where the trade wind originates.
She is characterized by clear blue sky, blue sea, weak excitement.
The weak wind is associated with the absence of strong and stable currents in the middle part of the belt. The waters of the North Trade Wind Current, the Gulf Stream, move clockwise around it. The oceanographic conditions of this part of the belt are determined by the Gulf Stream. The main process here is the transfer of a huge mass of warm (+26-+ 30 °C) tropical waters of high salinity (over 36%o) to higher latitudes.
There are countercurrents on both sides of the Gulf Stream. At the edges of the current, vortices (less than 50 km wide) are formed, rotating in the opposite direction.
Changes in the Gulf Stream have a strong impact on vast and remote areas of the North Atlantic. In addition, many tropical cyclones travel north along the Gulf Stream.
Within the belt are the Sargasso, Marmara, Black, Azov, Mediterranean, Ionian, Adriatic, Cretan, Aegean, and Tyrrhenian seas.
The northern tropical zone corresponds to the trade wind zone of the Northern Hemisphere between 10-12 and 25° N.
sh., includes the Caribbean Sea and most of the Gulf of Mexico.
Trade wind strength is on average 3-5, on the border of the subtropics 2-3, in equatorial latitudes 5-6, in winter up to 8 points. In summer, the trade wind zone shifts to the north, the strength of the wind decreases, but basically the trade wind is the most stable wind on Earth. In summer, the northern tropical zone includes intertropical convergence zone with equatorial air and abundant precipitation. The trade wind zone has dry winters and wet, rainy summers.
This climate corresponds to the savannah zone on land.
The belt is characterized by heating of surface waters. Layer thickness warm water in the east 10-15, in the west 75-150 m. The salinity of the water is high (36.0-36.5), the maximum salinity (about 37% o) is observed at depths of 50-200 m.
In tropical latitudes, storms are rare, but they arise and develop here every year. And two to four tropical cyclones move, in which the wind sometimes reaches hurricane force, i.e.
i.e. more than 30 m/s. Cyclones originate during the season of maximum heating (+ 28 °C) of surface waters in summer and autumn, mainly in the warmer, western areas ocean. In the area of the Antilles, powerful upward air currents develop over the heated surface of the water. They are visible visually in the form of cumulus clouds. The rising air carries with it large number water vapor. At altitude, steam condenses, additional latent heat of vaporization enters the atmosphere, and intense rain falls.
Due to the rise of air, the pressure drops to 715 mm Hg. st. and below. Air rushes into the resulting depression from all sides. Due to the rotation of the Earth, it is deflected to the right, forming a vortex with a diameter of 100-400 km, in which air rotates counterclockwise around a central area of low pressure at a speed of up to 100 m/s or more.
Energy and energy increase in proportion to the square of the speed. destructive force vortex. On the ocean, the cyclone creates powerful waves; on the shores, destruction is caused by wind, storm and unusually heavy rainfall, accompanied by extensive flooding.
The amount of precipitation on some islands reaches 1000 mm or more.
In the northern tropical zone, where the surface water temperature is almost everywhere above + 20 ° C, communities of coral reefs and mangroves, characteristic only of low latitudes, are common. But in the Atlantic Ocean they do not reach such development as in the Indian and Pacific.
The equatorial belt is located mainly in the Northern Hemisphere on both sides of the thermal equator between 10-12° N. w. and 0-3° S. w. It includes parts of the Northern and Southern Trade Wind Currents and a system of equatorial countercurrents.
The belt is dominated by an equatorial climate. It is characterized by a high temperature of the surface layer of water, a complex water circulation system with a predominance of rise, and relatively high bioproductivity. On the continents, this zone corresponds to the zone of moist equatorial forests.
The intertropical zone of convergence of the trade winds of the two hemispheres with intense rain passes through the belt twice a year (in spring and autumn).
Therefore, in the belt there are two seasons - spring and autumn - wet with the so-called zenithal rains (the sun passes through the zenith at this time), and two - winter and summer - relatively dry (the sun moves away from the equator, the trade wind penetrates into the belt, and at this time zenithal rains fall in the tropics, southern and northern respectively). The equator receives not only the energy of direct solar radiation, but also a large amount of latent heat of vaporization associated with warm air saturated with water vapor and driven by trade winds.
The equatorial belt collects moisture and heat from the vast tropical (trade wind) belts.
The trade winds of both hemispheres enter and gradually fade into the strip of the thermal equator. Between them there is usually always a strip of wind calm, calms and squalls up to 500 km wide. As a result of strong heating of the calm ocean surface, powerful upward currents of moist air close to the saturation state arise.
Their cooling during ascent causes condensation of vapors, the formation of large clouds and heavy rainfall, usually with thunderstorms.
Water temperature at surfaces During the year it changes little - by 1-3 “C. Salinity in in general close to normal, only in areas of high river flow - in the mouths of the Amazon, Orinoco - 34, and in the Gulf of Biafra - 32-33%.
The southern tropical zone is located between 0-3° S.
w. and 18° S. w. in the east and 30° south. w. in the west. The southeast trade wind dominates here. In his eastern parts of the Southern Trade Wind Current originates, which crosses the ocean from east to west with speed 0.5 m/s. The depth of the current is 300 m. The water temperature on the surface reaches + 27 “C, the salinity is high - 36% o.
Countercurrents are sometimes observed within the current flow. Hydrological regime of western districts caused by the Brazilian Current. The shelf here is narrow.
There is a large river flow in the belt, especially in the area where the Congo River flows into the ocean. Hurricanes are rare, and seasonal upwelling is noticeable. In coastal areas there is high bioproduction.
The southern subtropical belt is located between the zones of the South Trade Wind and Antarctic Circumpolar Currents.
Due to the presence of warm and cold currents, the boundaries of the belt off the coast of South America lie at higher latitudes, and at coast of Africa - closer to the equator.
The open ocean is characterized by intense solar radiation, low precipitation, high evaporation, and weak winds of variable directions. This explains the absence of powerful currents, the formation of warm (+16-I-18 °C), highly saline (36-37%0) waters, their immersion and low bioproductivity.
High bioproductivity on the shelf of Uruguay, where the waters of the La Plata River and the Falkland Current penetrate, as well as waters from the depths.
The southern temperate zone begins south of the subtropical convergence zone at 37- 40 ° south w. IN these latitudes, the Atlantic Ocean connects with the Pacific Ocean through the Drake Passage, as well as with the Indian Ocean south of Africa.
The belt is dominated by Western And northwest winds, deep cyclones moving from west to east, accompanied by stormy winds.
The frequency and severity of storms are high. Storms occur in any season, but most often in autumn and winter. Here, the environment is favorable for the development of wind waves - the unrestricted water space of the open ocean and great depths. Storm winds, without encountering any obstacles on their way, have great acceleration, wave heights are up to 20 m. The waves reach Cape Horn, which is known as one of the stormiest places in the world.
All year round there is low stratus cloudiness in the belt, frequent fogs and prolonged rains. The air temperature is low - + 10 in summer, 0 ° C in winter.
General information and physical-geographical location
The Atlantic Ocean is located mainly in. Western Hemisphere. From north to south it extends for 16 thousand.
km. In the northern and southern parts, the ocean expands, and in equatorial latitudes it sounds up to 2900 km.
The Atlantic Ocean is the second largest among the oceans. Ocean coastline in. The northern hemisphere is heavily dissected by peninsulas and bays. Continents in the ocean have many islands, internal and marginal seas
Bottom relief
It stretches across the entire ocean at approximately equal distances from the shores of the continents.
Mid-ocean ridge. The relative height of the ridge is 2 km. In the axial part of the ridge there is a rift valley from 6 to. ZO. km and a depth of up to 2 km. Transverse faults divide the ridge into separate segments. Associated with rifts and faults at mid-ocean ridges are active underwater volcanoes and volcanoes. And Slandia and. Azores Islands. The ocean has its greatest depth within the trench.
Puerto Rico - 8742 m. Shelf area. The Atlantic Ocean is quite large - larger than the. Pacific Ocean.
Climate
The Atlantic Ocean is located in all climate zones. Earth, so its climates are very diverse. Most of the ocean (between 40°N and 42°S) is located in the subtropical, tropical, subequatorial and equatorial climate zones. The southern parts of the ocean are characterized by a strict climate, and the northern regions are somewhat less cold.
Properties of waters and ocean currents
The zoning of water masses in the ocean is very complicated by the influence of land and sea currents, which is manifested primarily in the temperature distribution of surface waters.
The northern half of the ocean is warmer than the southern half, with different temperatures reaching up to 6 °. C. The average surface water temperature is 16.5 °C.
Salinity of surface waters c. Atlantic Ocean high. Many large rivers flow into the ocean and its seas (Amazon, Coigo, Mississippi, Nile, Danube, Parana, etc.). Ice forms in the desalinated bays and seas of subpolar and temperate latitudes in winter off the eastern shores.
A special feature of the ocean is the numerous icebergs and floating sea ice that are carried here from. Northern. Arctic Ocean and from the shores.
Antarcticatidi.
Due to strong elongation. The Atlantic Ocean from north to south has more developed ocean currents in the meridional direction than in the latitudinal one. In the Atlantic, two systems are formed on top of the currents. In the Northern Hemisphere it looks like a figure eight -. Northern. Passatnaya,. Gulf Stream. North Atlantic and. The Ka-Nar currents form a clockwise movement of water in temperate and tropical latitudes. In the northern part.
The North Atlantic Current guides the waters. Atlantic to North. Arctic Ocean counterclockwise. Like cold currents they return to. Atlantic Ocean in the northeastern part. B. Southern Hemisphere.
Passatnaya,. Brazilian,. Western. Vetrov and. The Benguela currents form a counterclockwise movement of water in the form of one ring.
Organic world
Atlantic Ocean compared to. Quiet had a poorer species composition of living organisms.
However, in terms of quantity and total biomass, then. The Atlantic Ocean is rich in organisms. This is primarily due to the significant spread of the shelf, on which many bottom and bottom fish live (cod, perch, flounder, etc.).
Natural complexes
The Atlantic Ocean is divided into all zonal complexes - natural zones, except for the North Polar. The waters of the north subpolar zone are rich various types living organisms - especially on the shelf near the berets. Greenland and. Labrador. The temperate zone is characterized by intense interaction between cold and warm waters and an abundance of living organisms.
These are the most fishing areas. Atlantic. Large expanses of warm waters of the subtropical, tropical and equatorial zones are less productive than the waters of the northern temperate zone.
In the northern subtropical zone there is a special natural water complex. Sargasovog in the sea. It is characterized by increased water salinity - up to 37.5% and low productivity.
In the temperate zone.
In the southern hemisphere (as in the northern) there are complexes where waters of different temperatures and densities mix. The complexes of the subantarctic and antarctic belts are characterized by the seasonal distribution of floating ice and icebergs.
Economic use
The Atlantic Ocean presents all types of maritime activities, among which the most important are maritime, transport, underwater oil and gas production, and only then - the use of biological resources
. Atlantic Ocean- the main sea route of the world, an area of intense shipping. On the banks.
The Atlantic Ocean is home to more than 70 coastal countries with a population of more than 1.3 billion people
The mineral resources of the ocean include placer deposits of rare metals, diamonds, and gold.
In the depths of the shelf, reserves of iron ore and sulfur are concentrated, large deposits of oil and gas have been discovered, and are exploited by many countries (North Sea, etc.). Some shelf areas are rich in coal.
Ocean energy is used to operate tidal power plants (for example, at the mouth of the Rance River in the north of France).
Many Atlantic countries extract from the ocean and its seas such mineral wealth as table salt, magnesium, bromine, uranium.
Desalination plants operate in dry areas
The biological resources of the ocean are also being intensively used. The Atlantic Ocean is the largest per unit area, but its biological resources are depleted in some areas
Due to intense economic activity In many seas in the open ocean, natural conditions are deteriorating - water and air pollution, a decrease in stocks of valuable commercial fish, etc.
Other animals. Recreational conditions on the ocean shores are deteriorating.
Source: statc.ru
All properties of water and natural processes in the World Ocean, the ecological situation in general and, accordingly, life change from the poles to the equator, that is, they have a pronounced zonal character. This allows-
It is possible to identify latitudinal physical-geographical belts in the World Ocean and outline the most common features their nature. D.V. Bogdanov identified eleven latitudinal divisions, which he called natural belts
Ocean: two polar, subpolar, temperate, subtropical and tropical zones and one equatorial (Fig. 86).
Polar (Arctic and Antarctic) belts occupy most of the Arctic and a narrow strip around Antarctica. The air and water there have a negative temperature throughout the year, so almost the entire year the water is bound by a continuous ice cover of sea pack and shelf ice. The vertical thermohaline circulation of water is weak, somewhat intensified in winter, but not observed in summer due to desalination of the upper layer. Due to weak mixing, the removal of nutrients from below is difficult. The belts are characterized by polar days and nights and auroras. In such a harsh ecological situation, life is extremely poor: the number of species and individuals is small. In summer, for a short period (1-1.5 months), phytoplankton appears in the polynyas, followed by zooplank.
Rice. 86. Natural zones of the World Ocean (according to D.V. Bogdanov)
tone - cold-loving fish and fish-eating pinnipeds (walruses and seals), as well as polar bears (only in the northern hemisphere). In Antarctica, the main inhabitants are penguins. Some other birds appear in summer. The economic importance of these belts is minimal: there are few fish and sea animals, and navigation is impossible due to the harsh ice conditions. On land, these belts correspond to ice deserts.
Subpolar (subarctic and subantarctic) belts. These include the marginal seas of Eurasia, North America and the ocean strip around Antarctica at a latitude of 60-70°. These are zones of the ice edge: in winter there is ice, in summer there is water. In winter, conditions are close to those of the polar zones: lack of light, negative temperatures, ice. In summer
The water temperature reaches 3 - 5 °C in the northern hemisphere, 2 - 3 °C in the southern hemisphere. There are an abundance of icebergs, a lot of sunlight and oxygen. Since intense thermohaline circulation occurs in winter up to the shelf and continental slope, water with abundant food rises upward, which is favorable for the development of life. During the short spring, a mass of phytoplankton develops, the water turns green, and a little later, in the summer, active development of zooplankton begins (many crustaceans, including krill up to 3-4 mm long). During this period, schools of fish and whales come here to feed. In summer, nesting places for many birds, including those that feed on fish, appear on the rocky shores of the islands, the so-called bird colonies: gulls, guillemots, cormorants, fulmars, etc. They feed the chicks with insects. During this period, there is a large fishery for both bottom fish (flounder, cod, halibut, haddock, sea bass) and pelagic fish (herring), as well as whales. In addition, seals from the Jan-Mayen and White Sea herds are still hunted. In summer, transport ships sail in these waters, but in a number of areas, the assistance of icebreakers is required for their passage. On land, these zones correspond to the tundra in the northern hemisphere and the tundra-meadow zone, otherwise called the oceanic meadow zone, in the southern hemisphere.
Temperate zones occupy large areas in both hemispheres. The water temperature is positive all year round (up to 12-15°C in summer, up to 5-8°C in winter), so there is no sea ice, with the exception of inland waters (for example, in the Baltic Sea), but there are icebergs. Salinity is 34 - 35% 0, there is enough oxygen. These are areas of westerly winds and currents. Winter cooling of surface water and an increase in its density causes significant vertical mixing and enrichment of the surface layers with nutrients. With sufficient heat in winter, this leads to intensive development life (abundance of individuals with a moderate number of species). Temperate zones are rich in fish (herring, cod, hake, navaga, saury, salmon, etc.). But since the layer of temperature jump is already expressed here, especially in summer, and above and below it there are different temperatures and, accordingly, environmental conditions, then fish are found in these layers different types For example, tuna in upper warm waters can swim as far as the UK. The commercial importance of these zones is great; both bottom-dwelling and pelagic fish are caught. The most important international shipping lines pass through the waters of this belt in the northern hemisphere. When navigating, one has to take into account currents, frequent storms, fogs, and icebergs. On land in
In the oceanic sectors of the continents, forests correspond to these belts.
Subtropical zones- These are strips at the latitude of the Sargasso and Mediterranean seas and the southern tips of Africa and Australia. In these zones, the temperature is high all year round (8-10° lower in winter than in summer), the temperature jump layer is well expressed, salinity is high - 37%o, and there is little oxygen. The waters are poor in nutrients, as their subsidence predominates. There is less plankton and, accordingly, fish and other organisms. The scale of fishing is modest: sardines, horse mackerel, mackerel, and tuna are caught, but mollusks and crustaceans are fished. On land, these zones correspond to the subtropics of the Mediterranean on the western coasts and deciduous forests on the eastern coasts.
Tropical zones wide, these are zones of trade winds, trade wind currents. Water temperatures are above 20 °C all year round, with the exception of narrow strips of coastal upwelling. The layer of temperature jump is clearly expressed, therefore there are significant temperature contrasts in depth, salinity is 36-37% 0, there is little oxygen in the water. There are few nutrients, and therefore plankton, the water is clear, blue, and the blue color of sea water is the color of the “sea desert”. Life in the sea is quantitatively relatively poor, but there is a wide variety of southern fish and other animals. Since there is not enough food in these belts, fish swim long distances in search of it. The only means of escape from predators is speed (up to 60 km/h). Therefore, the sharks that live here (they are mainly predators), mackerel, tuna, flying fish, sailfish, swordfish, etc. are excellent swimmers and have a muscular body. Due to the fact that the water in the tropics is oversaturated with carbonates, many mollusks and coral polyps build their internal skeleton and shells from it, while organogenic limestones gradually accumulate at the bottom. These belts have rich fisheries for mollusks and crustaceans. In coastal upwelling zones, life is richer (anchovy, etc.). In the past, this was a classic sailing area. On land, these zones correspond to zones of tropical deserts and savannas.
Equatorial belt- a narrow strip between the Northern and Southern trade wind currents, corresponding to the equatorial inter-trade wind countercurrent. It is associated with the rise of deep waters and the enrichment of the upper layers with nutrients. The water temperature is high all year round, but the layer of warm water is small - only 20 - 50 m; below there is a layer of temperature jump. In this
The belt has a diverse and vibrant life; the number of species in the seas of the Sunda archipelago, for example, is a hundred times greater than in the Arctic seas. At the bottom of the ocean, in the coral “shelter buildings,” there are many clumsy “sedentary” fish, like rock bass. “Flashes” of life are observed near the mouths of rivers - the Amazon, Niger, etc., as the rivers carry out nutrients. Due to the abundance of phyto- and zooplankton and suspended matter, the water is very turbid, so there are few predator fish and many juveniles, which are safe here. The main commercial fish are tuna, swordfish, sardines, and mackerel. But trawl fishing is difficult because of the reefs. Fishing objects also include sea turtles, corals, pearl shells, and sponges. In mangroves on low coasts up to a width of
50 km there are a lot of mollusks and crustaceans. On land, this belt corresponds to equatorial forests.
The named ocean belts are located somewhat asymmetrically relative to the equator: in the southern hemisphere they are shifted to the north. Moreover, due to the fact that in the southern hemisphere the influence of the continents is small, zonality in the ocean is more pronounced than in the northern hemisphere.
The identification of natural zones in the Ocean is not only of scientific interest, complementing the picture of the physical-geographical zonation of the globe. Like any natural zoning, it has practical significance, since it identifies areas that are promising for the development of fishing and other industries.
The organic world of the Atlantic Ocean depends on temperature, salinity and other indicators characterizing the water area of this part of the Moscow Region. Living conditions for organisms change significantly from north to south. Therefore, in the Atlantic there are areas rich in natural resources and relatively poor areas where the number of animal species is in the tens, not hundreds.
The role of living organisms in the natural complex of microorganisms
The organic world of the Atlantic Ocean is significantly influenced by the large extent of the water area from north to south. The diversity of animals and plants is influenced by vast areas of land runoff and other natural factors. The expanses of the sea, the bottom and the surf are home to thousands of organisms that belong to different kingdoms nature of the Earth. Plants and animals are the most important components of the natural complex. They are influenced by climate, the composition and properties of water, and the rocks that make up the bottom. In turn, the organic world of the Atlantic Ocean influences other components of nature:
- algae enrich the water with oxygen;
- the respiration of plants and animals leads to an increase in carbon dioxide levels;
- skeletons of coelenterate colonies form the basis of coral reefs and atolls;
- Living organisms absorb mineral salts from water, reducing their amount.
Organic world of the Atlantic Ocean (briefly)
Temperature and salinity values are critical for the microscopic living creatures that make up plankton, as well as algae. These indicators are important for nekton - animals that freely swim in the water column. The relief features of the shelf and ocean floor determine the life activity of bottom organisms - benthos. This group includes many coelenterates and crustaceans. There are a number of features of species composition that characterize the organic world of the Atlantic Ocean. The photo of the seabed presented below makes it possible to verify the diversity of benthos in subtropical and tropical latitudes. Fish-rich waters are confined to areas of intensive plankton reproduction in temperate and hot zones. These same regions also support a diversity of seabirds and mammals. High latitudes in the north and south are characterized by the predominance of birds that feed on the surface of ice-free water, and nesting colonies are built on the shore.
Phytoplankton
They constitute an important part of plankton. This group includes diatoms, blue-greens, flagellates and other tiny living organisms capable of photosynthesis. They inhabit water columns up to 100 m deep, but highest density observed in the first 50 m from its surface. Intense solar radiation in the warm season leads to rapid development of phytoplankton - “blooming” of water in the temperate and subpolar latitudes of the Atlantic Ocean.
Large plants
Photosynthetic green, red, brown algae and other representatives of the MO flora are an important part of the natural complex. Thanks to plants, the entire organic world of the Atlantic Ocean receives oxygen for breathing and nutrients. The list of bottom vegetation or phytobenthos includes not only algae, but also representatives of angiosperms that have adapted to living in salt water, for example the genera Zoster and Posidonia. These “sea grasses” prefer soft subtidal soils and form underwater meadows at depths of 30 to 50 m.
Typical representatives of the flora of the continental shelf in the cold and temperate zones on both sides of the equator are kelp. They attach to bottom rocks and single stones. Marine vegetation in the hot zone is poorer due to high temperatures and significant insolation.
Economic importance of algae:
- brown (kelp) - used as food, used to obtain iodine, potassium and algin;
- red algae - raw materials for the food and pharmaceutical industries;
- brown sargassum algae is a source of algin.
Zooplankton
Phytoplankton and bacteria are food for herbivorous microscopic animals. Floating freely in the water column, they constitute zooplankton. It is based on the smallest representatives of crustaceans. Larger ones are combined into meso- and macroplankton (comb jellies, siphonophores, jellyfish, shrimp and small fish).
Nekton and benthos
There is a large group of living organisms in the ocean that are able to withstand the pressure of water and move freely in its thickness. Medium-sized and large-sized marine animals have such abilities.
- Crustaceans. Shrimp, crabs and lobsters belong to this subtype.
- Shellfish. Typical representatives of the group are scallops, mussels, oysters, squid and octopus.
- Fish. The genera and families of this superclass are the most numerous - anchovies, sharks, flounder, sprat, salmon, sea bass, capelin, pollock, haddock, halibut, sardines, herring, mackerel, cod, tuna, hake.
- Reptiles. A few representatives are sea turtles.
- Birds. Penguins, albatrosses, and petrels forage for food in the water.
- Marine mammals. Highly organized animals - dolphins, whales, fur seals, seals.
The basis of the benthos is made up of animals that lead an attached lifestyle on the bottom, for example, coelenterates (coral polyps).
Features of plants and animals of the Atlantic
- In the northern and southern parts of the basin, the presence of different species and genera in the fauna is noted.
- There are few plankton species, but total mass reaches impressive values, especially in the temperate climate zone. Foraminifera, pteropods and (krill) predominate.
- High bioproductivity is a feature that characterizes the characteristics of the organic world of the Atlantic Ocean. It is distinguished by a significant density of life in shallow waters near the island of Newfoundland, water areas to the southwest and northwest of the coast of Africa, marginal seas and the eastern shelf of the USA and South America.
- The tropical zone, as noted above, is an unfavorable area for phytoplankton.
- The productivity of Atlantic Ocean nekton on the shelf and part of the continental slope is higher than in similar areas of neighboring oceans. The predominant species are fish that feed on phyto- and zooplankton (anchovies, herring, mackerel, mackerel and others). In open waters, tuna are of commercial importance.
- The species richness of mammals is one of the features of the animal world of the Atlantic Ocean. In the past century, they were subjected to significant extermination, and their numbers decreased.
- Coral polyps are not as diverse as in the Pacific basin. Few sea snakes and turtles.
There are various factors that explain many of the listed features that characterize the organic world of the Atlantic Ocean. The conclusion from everything said above suggests the following: the reasons for the differences are associated with the small width of the Atlantic in the hot zone, expansion in the temperate and subpolar regions. On the contrary, the Pacific and Indian oceans have their greatest extent in the tropical zone. Another factor that influenced the relative poverty of the Atlantic in heat-loving animals was the influence of the last glaciation, which caused significant cooling in the Northern Hemisphere.
Organic world of the Atlantic Ocean: fishery objects
Temperate and tropical latitudes in the Northern and Southern Hemispheres are rich in life. Fish species of commercial importance include anchovies, pollock, tuna, cod, hake and others. Mammals are hunted: whales and fur seals. Other types of biological resources are represented by mollusks, crustaceans, brown and red algae. Ocean plants are used for pet food and industrial processing. Most shellfish are delicacies, valued in the cuisine of many countries (oysters, squid, octopus, the same characteristic can be given to crustaceans, including lobsters, shrimp and crabs.
Fishing and seafood production is more intensive on the shelf and in the area of continental slopes. But in recent decades, areas of the water area that previously experienced less strong anthropogenic influence have been brought into economic circulation. Therefore, they are escalating environmental problems not only coastal areas, but the entire ocean.