What oceans are these seas related to? They belong to the world's oceans. Chemical composition of water
The ocean (ancient Greek Ὠκεανός, on behalf of the ancient Greek deity of the Ocean) is the largest water body, a component of the World Ocean, located among the continents, with a water circulation system and other specific features. The ocean is in continuous interaction with the atmosphere and the earth's crust. The surface area of \u200b\u200bthe world's oceans, which includes oceans and seas, is about 71 percent of the Earth's surface (about 361 million square kilometers). The relief of the bottom of the Earth's oceans as a whole is complex and varied.
The science that studies the oceans is called oceanology; the fauna and flora of the ocean is studied by a branch of biology called ocean biology.
Antique meaning
In ancient Rome, the word Oceanus denoted the waters that washed the known world from the west, that is, the open Atlantic Ocean. In this case, the expressions Oceanus Germanicus ("German Ocean") or Oceanus Septentrionalis ("Northern Ocean") denoted the North Sea, and Oceanus Britannicus ("British Ocean") - the English Channel.
Modern definition of oceans
The World Ocean is the global volume of seawater, the main part of the hydrosphere, which makes up 94.1% of its total area, a continuous, but not continuous, water shell of the Earth, surrounding continents and islands and characterized by a common salt composition. Continents and large archipelagos divide the world's oceans into parts (oceans). Large regions of the oceans are known as seas, bays, straits, etc.
Some sources divided the oceans into four parts, others into five. From 1937 to 1953, five oceans were distinguished: Quiet, Atlantic, Indian, Northern Ice and Southern (or Southern Arctic) ocean. The term "Southern Ocean" appeared many times in the 18th century, when a systematic study of the region began. In the publications of the International Hydrographic Organization, the Southern Ocean from the Atlantic, Indian and Pacific was separated in 1937. This was its own rationale: in its southern part, the boundaries between the three oceans are very conditional, at the same time the waters adjacent to Antarctica have their own specificity, and are also united by the Antarctic circumpolar current. However, later on, the allocation of a separate Southern Ocean was abandoned. In 2000, the International Hydrographic Organization adopted the division into five oceans, but this decision has not yet been ratified. In the current 1953 definition of oceans, there is no Southern Ocean.
In the table below, in addition to the seas related to the oceans, the seas related to the Southern Ocean are also indicated.
|
Area, million km² |
Volume, million km³ |
Average depth, m |
Maximum depth, m |
||
| Atlantic |
8,742 (Puerto Rico gutter) |
Baltic, North, Mediterranean, Black, Sargasso, Caribbean, Adriatic, Azov, Balearic, Ionian, Irish, Marble, Tyrrhenian, Aegean; Bay of Biscay, Gulf of Guinea, Gulf of Mexico, Hudson Bay : Weddell, Scotia, Lazareva |
|||
| Indian |
7 725 (Sunda Trench) |
Andaman, Arabian, Arafur, Red, Lakkadiv, Timor; Bay of Bengal, Persian Gulf Also related to the Southern Ocean: Riiser-Larsen, Davis, Astronauts, Commonwealth, Mawson |
|||
| Arctic |
5 527 (in the Greenland Sea) |
Norwegian, Barents, White, Kara, Laptev, East Siberian, Chukchi, Greenland, Beaufort, Baffin, Lincoln | |||
| Quiet |
11 022 (Mariana Trench) |
Beringovo, Okhotsk, Japanese, East China, Yellow, South China, Javan, Sulawesi, Sulu, Philippine, Coral, Fiji, Tasmanovo Also related to the Southern Ocean: Durville, Somov, Ross, Amundsen, Bellingshausen |
Brief description of the oceans
The Pacific Ocean (or Great) is the largest ocean in area and depth on Earth. Located between the continents of Eurasia and Australia in the west, North and South America in the east, Antarctica in the south. In the north, through the Bering Strait, it communicates with the waters of the Arctic, and in the south - the Atlantic and Indian oceans. Occupying 49.5% of the surface of the World Ocean and containing 53% of the water volume of the World Ocean, the Pacific Ocean extends approximately 15.8 thousand km from north to south and 19.5 thousand km from east to west. The area with the seas is 179.7 million km2, the average depth is 3984 m, the volume of water is 723.7 million km3 (without the seas, respectively: 165.2 million km2, 4282 m and 707.6 million km3). The greatest depth of the Pacific Ocean (and the entire World Ocean) is 11,022 m in the Mariana Trench. The date line runs across the Pacific Ocean along the 180th meridian. The study and development of the Pacific Ocean began long before the written history of mankind appeared. For sailing on the ocean, junks, catamarans and simple rafts were used. The 1947 expedition on the Kon-Tiki balsa log raft led by the Norwegian Thor Heyerdahl proved the possibility of crossing the Pacific Ocean westward from central South America to the Polynesian islands. Chinese junks made treks along the shores of the ocean to the Indian Ocean (for example, the seven voyages of Zheng He in 1405-1433). Currently, the coast and islands of the Pacific Ocean are developed and populated extremely unevenly. The largest centers of industrial development are the US coast (from the Los Angeles area to the San Francisco area), the coast of Japan and South Korea. The ocean plays a significant role in the economic life of Australia and New Zealand.
The second largest ocean on Earth after the Pacific Ocean, the name comes from the name of the titan Atlas (Atlanta) in Greek mythology or from the legendary island of Atlantis. It stretches from subarctic latitudes to Antarctica itself. The border with the Indian Ocean runs along the meridian of Cape Agulhas (20 ° E to the coast of Antarctica (Queen Maud Land). The border with the Pacific Ocean is drawn from Cape Horn along the meridian 68 ° 04 'W or the shortest distance from South America to the Antarctic Peninsula through Drake Passage, from Oste Island to Cape Sternek.The border with the Arctic Ocean runs along the eastern entrance of the Hudson Strait, then through the Davis Strait and along the coast of Greenland to Cape Brewster, through the Danish Strait to Cape Reidinupur on Iceland, along its coast to Cape Gerpier, then to the Faroe Islands, then to the Shetland Islands and 61 ° north latitude to the coast of the Scandinavian Peninsula.The area of \u200b\u200bseas, bays and straits of the Atlantic Ocean is 14.69 million km2 (16% of the total ocean area), volume 29.47 million km³ (8.9%) Area 91.6 million km2, of which about a quarter is inland seas The area of \u200b\u200bcoastal seas is small and does not exceed 1% from the total area of \u200b\u200bthe water area. The volume of water is 329.7 million km3, which is equal to 25% of the volume of the World Ocean. The average depth is 3736 m, the greatest is 8742 m (the trench of Puerto Rico). The average annual salinity of ocean waters is about 35 ‰. The Atlantic Ocean has a strongly indented coastline with a pronounced division into regional waters: seas and bays.
The Indian Ocean is the third largest ocean on Earth, covering about 20% of its water surface. The Indian Ocean is mainly located south of the Tropic of Cancer between Eurasia in the north, Africa in the west, Australia in the east, and Antarctica in the south.
Its area is 76.17 million km2, volume - 282.65 million km3. In the north it washes Asia, in the west - the Arabian Peninsula and Africa, in the east - Indochina, the Sunda Islands and Australia; in the south it borders the Southern Ocean.
The border with the Atlantic Ocean runs along the 20 ° east longitude meridian; with Tikhim - along 147 ° east longitude meridian.
The northernmost point of the Indian Ocean lies at about 30 ° north latitude in the Persian Gulf. The Indian Ocean is approximately 10,000 km wide between the southern points of Australia and Africa.
The Arctic Ocean (Eng. Ishavet, Norwegian and Nynorsk Nordishavet) is the smallest ocean on Earth, located between Eurasia and North America.
The area is 14.75 million km2, that is, slightly more than 4% of the entire area of \u200b\u200bthe World Ocean, the average depth is 1,225 m, the volume of water is 18.07 million km3.
The Arctic Ocean is the shallowest of all oceans, with an average depth of 1,225 m (maximum depth is 5,527 m in the Greenland Sea).
Oceans formation
Today in scientific circles there is a version that the ocean appeared 3.5 billion years ago as a result of the degassing of magma and the subsequent condensation of atmospheric vapors. Most of the ocean basins of our time arose in the last 250 Ma as a result of the split of the ancient supercontinent and the divergence (so-called spreading) of lithospheric plates. The exception is the Pacific Ocean, which is the shrinking remnant of the ancient Panthalassa Ocean.
Bathymetric position
According to the bathymetric position and the nature of the relief on the ocean floor, several stages are distinguished:
- Shelf - depth up to 200-500 m
- Continental slope - depth up to 3500 m
- Ocean bed - depth up to 6000 m
- Deep water troughs - depth below 6,000 m
Ocean and atmosphere
The ocean and atmosphere are fluids. The properties of these environments determine the habitat of organisms. Flows in the atmosphere affect the general circulation of water in the oceans, and the properties of ocean waters depend on the composition and temperature of the air. In turn, the ocean determines the basic properties of the atmosphere and is a source of energy for many processes occurring in the atmosphere. The circulation of water in the ocean is influenced by winds, the rotation of the Earth, and land barriers.
Ocean and climate
The ocean heats up more slowly in summer and cools more slowly in winter. This makes it possible to smooth out temperature fluctuations on the land adjacent to the ocean.
The atmosphere receives from the ocean a significant part of the heat supplied to it and almost all of the water vapor. The vapor rises, condenses, forming clouds, which are carried by the winds and poured as rain or snow onto land. Only the surface waters of the ocean are involved in heat and moisture exchange. Internal ones (about 95%) do not participate in the exchange.
Chemical composition of water
There is an inexhaustible source of chemical elements in the ocean, which is contained in the composition of its water, as well as in deposits located at the bottom. There is a constant renewal of mineral deposits, by the fallout or introduction of various sediments and solutions from the earth's crust to the bottom.
The average salinity of sea water is 35 ‰. The salty taste of the water is given by the 3.5% dissolved mineral substances contained in it - these are mainly sodium and chlorine compounds.
Due to the fact that the water in the ocean is constantly mixed by waves and currents, its composition is almost the same in all parts of the ocean.
Flora and fauna
The Pacific Ocean accounts for more than 50% of the total biomass of the World Ocean. Life in the ocean is abundant and varied, especially in the tropical and subtropical zones between the coasts of Asia and Australia, where vast areas are occupied by coral reefs and mangroves. The phytoplankton of the Pacific Ocean is mainly composed of microscopic unicellular algae, numbering about 1300 species. In the tropics, fucus, large green and especially famous red algae are especially common, which, along with coral polyps, are reef-forming organisms. 
The flora of the Atlantic is distinguished by its species diversity. The water column is dominated by phytoplankton, consisting of dinoflagellates and diatoms. In the midst of their seasonal bloom, the sea off the coast of Florida turns bright red, and a liter of seawater contains tens of millions of unicellular plants. The bottom flora is represented by brown (fucus, kelp), green, red algae and some vascular plants. At the mouths of the rivers, the sea zostera, or scum grows, and in the tropics, green (Caulerpa, Valonia) and brown (Sargassum) algae prevail. The southern part of the ocean is characterized by brown algae (fucus, lesonia, elektus). The fauna is distinguished by a large - about a hundred - number of bipolar species that live only in cold and temperate zones and are absent in the tropics. First of all, these are large sea animals (whales, seals, seals) and ocean birds. In tropical latitudes, sea urchins, coral polyps, sharks, parrotfish and surgeon fish live. Dolphins are often found in the waters of the Atlantic. Cheerful intellectuals of the animal world willingly accompany large and small vessels - sometimes, unfortunately, falling under the merciless blades of the propellers. The indigenous inhabitants of the Atlantic are the African manatee and the largest mammal on the planet, the blue whale.
The flora and fauna of the Indian Ocean are extremely diverse. The tropical region stands out for its rich plankton. The unicellular alga Trichodesmia (a type of Cyanobacteria) is especially abundant, due to which the surface layer of water becomes very cloudy and changes its color. The plankton of the Indian Ocean is distinguished by a large number of organisms glowing at night: peridinia, some species of jellyfish, ctenophores, tunicates. Brightly colored siphonophores are abundant, including poisonous phasaliae. In temperate and arctic waters, the main representatives of plankton are copepods, euphoazids and diatoms. The most abundant fish in the Indian Ocean are coryphans, tuna, notothenium and a variety of sharks. From reptiles there are several species of giant sea turtles, sea snakes, from mammals - cetaceans (toothless and blue whales, sperm whales, dolphins), seals, and elephant seals. Most cetaceans live in the temperate and circumpolar regions, where, due to the intensive mixing of waters, favorable conditions for the development of planktonic organisms arise. The flora of the Indian Ocean is represented by brown (sargassum, turbinaria) and green algae (caulerna). Lithotamnia and khalemeda, which together with corals participate in the construction of reef structures, are also richly developed. Typical for the coastal zone of the Indian Ocean is a phytocenosis formed by mangrove thickets. For temperate and Antarctic waters, red and brown algae are most characteristic, mainly from the groups of fucus and laminaria, porphyry, and gelidium. In the circumpolar regions of the southern hemisphere, giant macrocystis are found.
The reason for the poverty of the organic world of the Arctic Ocean is the harsh climatic conditions. The only exceptions are the North European Basin, the Barents and White Seas with their extremely rich flora and fauna. The flora of the ocean is represented mainly by kelp, fucus, anfelcia, and in the White Sea - also zoster. The fauna of the seabed of the eastern Arctic, especially the central part of the Arctic basin, is extremely poor. In the Arctic Ocean, there are more than 150 species of fish, including a large number of commercial fish (herring, cod, salmon, scorpion fish, flounder and others). Seabirds in the Arctic are predominantly colonial and live on the shores. Mammals are represented by seals, walruses, beluga whales, whales (mainly minke and bowhead whales), and narwhals. Lemmings can be found on the islands, and Arctic foxes and reindeer cross the ice bridges. A representative of the ocean fauna should also be considered a polar bear, whose life is mainly associated with drifting, pack ice or coastal fast ice. Most animals and birds all year round (and some only in winter) are white or very light in color.
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Our Earth from space looks like a blue planet. This is because ¾ of the earth's surface is occupied by the World Ocean. He is one, although he is strongly divided.
The surface area of \u200b\u200bthe entire World Ocean is 361 million square meters. km.
The oceans of our planet
The ocean is the watery shell of the earth, the most important component of the hydrosphere. The continents divide the oceans into parts.
Currently, it is customary to distinguish five oceans:
. - the largest and oldest on our planet. Its surface area is 178.6 million square meters. km. It occupies 1/3 of the Earth and makes up almost half of the World Ocean. To imagine this value, suffice it to say that all continents and islands combined can be easily accommodated in the Pacific Ocean. This is probably why it is often called the Great Ocean.
The Pacific Ocean owes its name to F. Magellan, who, during his round-the-world voyage, crossed the ocean under favorable conditions.
The ocean has an oval shape, its widest part is located in the equator.
The southern part of the ocean is an area of \u200b\u200bcalm, light winds and a stable atmosphere. To the west of the Tuamotu Islands, the picture changes dramatically - there is an area of \u200b\u200bstorms and squall winds, turning into fierce hurricanes.
In the tropics, the waters of the Pacific Ocean are clear, transparent and have a deep blue color. A favorable climate has formed near the equator. The air temperature here is + 25ºC and practically does not change throughout the year. Winds of moderate strength, calm often sets in.
The northern part of the ocean is similar to the southern one, as if in a mirror image: in the west, unstable weather with frequent storms and typhoons, in the east - calm and quiet.
The Pacific Ocean is the richest in the number of species of animals and plants. More than 100 thousand species of animals live in its waters. Almost half of the world's fish catch is caught here. The most important sea routes have been laid across this ocean, linking 4 continents at once.
. covers an area of \u200b\u200b92 million square meters. km. This ocean, like a huge strait, connects the two poles of our planet. In the center of the ocean runs the Mid-Atlantic Ridge, famous for the instability of the earth's crust. Individual peaks of this ridge rise above the water and form islands, the largest of which is Iceland.
The southern part of the ocean is affected by the trade winds. There are no cyclones here, so the water is calm, clean and transparent. Closer to the equator, the Atlantic changes completely. The waters are muddy here, especially along the coast. This is due to the fact that large rivers flow into the ocean in this part.
The northern tropical belt of the Atlantic is famous for its hurricanes. The two largest currents meet here - the warm Gulf Stream and the cold Labrador stream.
The northern latitudes of the Atlantic are the most picturesque area with huge icebergs and powerful ice tongues protruding from the waters. This area of \u200b\u200bthe ocean is dangerous for shipping.
. (76 million sq. Km) - the region of the most ancient civilizations. Seafaring began to develop here much earlier than in other oceans. The average depth of the ocean is 3700 meters. The coastline is weakly indented, with the exception of the northern part, where most of the seas and bays are located.
The waters of the Indian Ocean are saltier than others, as far fewer rivers flow into it. But, thanks to this, they are famous for their amazing transparency and rich azure and blue colors.
The northern part of the ocean is a monsoon region, typhoons are often formed in autumn and spring. Closer to the south, the water temperature is lower due to the influence of Antarctica.
. (15 million sq. Km) is located in the Arctic and occupies vast areas around the North Pole. The maximum depth is 5527m.
The central part of the bottom is a continuous intersection of mountain ranges, between which there is a huge depression. The coastline is heavily cut by seas and bays, and in terms of the number of islands and archipelagoes, the Arctic is second only to such a giant as the Pacific Ocean.
The most characteristic part of this ocean is the presence of ice. The Arctic Ocean remains by far the least explored, as research is hampered by the fact that most of the ocean is hidden under ice cover.
. ... The waters surrounding Antarctica combine features. Allowing to highlight them in a separate ocean. But there are still debates about what to consider as boundaries. If from the south the borders are marked by the continent, then the northern borders are most often drawn at 40-50º south latitude. Within such limits, the ocean area is 86 million square meters. km.
The bottom relief is cut by underwater canyons, ridges and hollows. The fauna of the Southern Ocean is rich, with the largest number of endemic animals and plants.
Characteristics of the oceans
The world's oceans are already several billion years old. Its prototype is the ancient ocean of Panthalassa, which existed when all continents were still a single whole. Until recently, it was assumed that the bottom of the oceans is flat. But it turned out that the bottom, like the land, has a complex relief, with its own mountains and plains.
Properties of the world's oceans
The Russian scientist A. Voyekov called the World Ocean "a huge heating battery" of our planet. The fact is that the average water temperature in the oceans is + 17ºC, and the average air temperature is + 14ºC. Water heats up much longer, but also consumes heat more slowly than air, while possessing high heat capacity.
But not all the water column in the oceans is at the same temperature. Only the surface water heats up under the sun, and the temperature drops with depth. It is known that at the bottom of the oceans the average temperature is only + 3ºC. And it remains so because of the high density of water.
It should be remembered that the water in the oceans is salty, and therefore it freezes not at 0ºC, but at -2ºC.
The degree of salinity of waters varies depending on geographical latitude: in temperate latitudes the waters are less salty than, for example, in the tropics. In the north, the waters are also less salty due to the melting of glaciers, which greatly desalinates the water.
The waters of the ocean are not the same in terms of transparency. At the equator, the water is more transparent. As the distance from the equator increases, the water becomes saturated with oxygen faster, which means more microorganisms appear. But near the poles, due to low temperatures, the waters again become more transparent. So, the waters of the Weddell Sea near Antarctica are considered the most transparent. The second place belongs to the waters of the Sargasso Sea.
The difference between the ocean and the sea
The main difference between the sea and the ocean is in size. The oceans are much larger, and the seas are often only part of the oceans. The seas also differ from the ocean to which they belong to the basin, in a unique hydrological regime (water temperature, salinity, transparency, distinctive flora and fauna compositions).
Oceans climate
Pacific climate infinitely diverse, as the ocean is located in almost all climatic zones: from equatorial to subarctic in the north and Antarctic in the south. 5 warm currents and 4 cold currents circulate in the Pacific Ocean.
The greatest amount of precipitation falls in the equatorial zone. The amount of precipitation exceeds the proportion of water evaporation, so the water in the Pacific Ocean is less salty than in others.
Atlantic climate defined by its great length from north to south. The equator zone is the narrowest part of the ocean, so the water temperature is lower here than in the Pacific or Indian.
The Atlantic is conventionally divided into northern and southern, drawing the border along the equator, and the southern part is much colder due to its proximity to Antarctica. Many areas of this ocean are characterized by thick fogs and powerful cyclones. They are most powerful near the southern tip of North America and in the Caribbean.
To form indian Ocean climate the proximity of two continents - Eurasia and Antarctica has a huge impact. Eurasia actively participates in the annual change of seasons, bringing dry air in winter and filling the atmosphere with excess moisture in summer.
The proximity of Antarctica leads to a decrease in water temperature in the southern part of the ocean. Frequent hurricanes and storms occur north and south of the equator.
Formation the Arctic Ocean climate due to its geographic location. Arctic air masses dominate here. Average air temperature: -20 ºC to -40 ºC, even in summer the temperature rarely rises above 0ºC. But ocean waters are warmer due to constant contact with the Pacific and Atlantic oceans. Therefore, the Arctic Ocean heats a significant part of the land.
Strong winds are rare, but fogs are frequent in summer. Precipitation falls mainly in the form of snow.
It is influenced by the proximity of Antarctica, the presence of ice and the absence of warm currents. It is dominated by the Antarctic climate with low temperatures, cloudy weather and mild winds. Snow falls throughout the year. A distinctive feature of the Southern Ocean climate is the high activity of cyclones.
The influence of the ocean on the Earth's climate
The ocean has a tremendous impact on the formation of the climate. It accumulates huge reserves of heat. Thanks to the oceans, the climate on our planet is becoming milder and warmer, since the temperature of the waters in the oceans does not change as sharply and quickly as the air temperature over land.
The oceans promote better air circulation. And such an important natural phenomenon as the water cycle provides the land with a sufficient amount of moisture.
The oceans cover about 70% of the surface of our planet. Thus, it is a water shell stretched over almost the entire surface of the Earth. The world's oceans are continuous, and it washes land areas from all sides, be they continents or islands.
By these very land areas, the world ocean is divided into 4 huge parts, which are called oceans. Each of them has its own characteristics, and, of course, its own name: Atlantic Ocean, Indian Ocean, Pacific Ocean, Arctic Ocean. In addition, there is also a fifth ocean - the South, which is slightly different from the rest. The science of oceanology is engaged in their study.
Some parts of the world's oceans are separated from it by land or underwater relief. As a rule, they have different temperatures, salinity levels and other indicators. These parts are called seas. They are located near land, and in some cases they may even be on the mainland, and have no communication with the oceans. In other words, the sea is a very large salt lake, which may not have clear boundaries, but simply pass into the ocean in some place.
Also an important part of the oceans are bays and straits.
As we already know, water washes the continents from all sides. And far from everywhere the coastline is a flat strip. There are many areas where the seas and oceans cut quite deep into the land, while maintaining free water exchange. Such parts of the world's oceans are called bays.
Well, among other things, there are also straits. They are also an integral part of the world's oceans. After all, the straits are water spaces connecting adjacent water basins (and their parts), and at the same time sandwiched between two parts of the land.
Phenomena in the World Ocean
1. In some places on the ocean floor there are cracks. Various substances seep through them: methane, hydrogen sulfide and others. After that, the substances mix with water and float along the ocean floor, like rivers. Underwater rivers, sounds great, right? This phenomenon is called cold seepage.
2. Another miracle of the world's oceans are underwater waterfalls. They are formed due to the difference in temperature and salinity of the waters, as well as the complex bottom topography. Such waterfalls are huge masses of denser water that rush sharply downward and replace less dense water. In total, less than a dozen underwater waterfalls are known, although their account can go to hundreds.
3. The depths of the ocean can be recognized by acoustic sounding (sound waves). In the middle of the 20th century, it became known that this method could fail. Then the "bottom" was discovered at a depth of 400 meters (incredible!). And later it turned out at all that this “bottom” either rises to the surface, then descends into the depths. Later, after various studies, it became clear that this effect was achieved thanks to squid. They can move in dense groups in which individuals are evenly distributed. This creates a false bottom.
4. Sometimes in the oceans there are very large areas of light. They are called milk seas. It is believed that this glow is due to luminescent bacteria, but it is too early to say for sure.
5. Ocean currents are streams of water moving in the oceans along certain routes. Carrying huge masses of water, they have a great influence on the formation of the world climate.
This is especially true of the coastal parts of the continents.
Living world of the oceans
Today, the oceans are one of the least explored parts of the Earth. According to the most optimistic statements, only about 5% of the world's oceans have been studied. But even these 5% allow us to imagine how diverse and interesting the underwater world of the oceans is.
The oceans are home to many living organisms. Of these, about 200 thousand species are known to science, but studies show that this is only a tenth. Thus, it remains only to fantasize what the remaining 2 million species of organisms are. What incredible animals are hiding in the ocean depths? If we rely on already known information, then the imagination can lead us very far.
Most deep-sea fish (living at a depth of more than 1 km) have relatively small eyes (or do not have them at all), since almost no light gets there. They also lead an almost immobile lifestyle, trying to conserve energy in this way. After all, there is almost no food for them at such depths. And therefore, by the way, most of the deep-sea fish are quite small. The big ones simply won't be able to feed themselves. But small, they are small, but they can eat more than they weigh themselves, which is why their belly swells greatly. Can you imagine such swallows? And they also know how to fish, no matter how strange it may sound. Not literally, of course. These fish lure their victims, attract them, and then eat them.
Conclusion
The World Ocean is an unknown mysterious underwater world. All that we know about him is a pitiful crumbs of knowledge. And it's great! After all, there are many incredible discoveries ahead of us, you just have to make a little effort.
Under By the oceans refers to the body of water occupied by all oceans and seas and providing a continuous liquid shell of the globe.
The distribution of land and sea on the globe is very uneven. In the northern hemisphere, 60.7% is under the oceans, and 39.3% of the total surface under the continents; in the southern hemisphere, respectively, 80.9% and 19.1%.
The oceans are divided into 4 oceans:
Quiet, Atlantic, Indian and North-Arctic.
The isolated parts of the oceans protruding into the land are called seas.
According to the classification of Yu.M. Shokal seas are subdivided into Mediterranean and marginal.
Mediterraneanseas, in turn, are divided into intercontinental(Mediterranean Sea) located between two continents (Africa, Europe) and inland (Baltic, White) seas.
Fringethe seas (Bering, Okhotsk, Japanese, etc.) are separated from the ocean by a chain of islands or peninsulas.
There are about 50 seas in the World Ocean. The World Ocean also includes: bays, estuaries, lagoons, straits and other parts of it that need to be known for the needs of navigation.
Bays called the parts of the oceans and seas, protruding into the land and gradually decreasing in width and depth. Depending on their shape, they are called: lip, bay, lagoon, fjords, etc.
Lip these are sea bays that protrude far into the land, into which large rivers usually flow (Onega Bay, Obskaya Bay).
Estuary This is the mouth of a river valley or gully flooded by the sea as a result of some subsidence of the land.
By the bay called a small bay, whose mouth width is less than the bay itself (Gelyandinsaya Bay, Sovetskaya Gavan, Sevastopol, Tsemesskaya, etc.)
Lagoon- these are inland shallow water bodies of ring-shaped islands (attons) or parts of the seas, separated from the sea by an oblique in whole or in part.
Fiord– it is a narrow, long, winding bay with high and steep shores, separated by an underwater threshold from the depths of the sea.
Fiords are typical of the coast of Norway.
Straitit is a relatively narrow body of water separating land areas and connecting two vast water basins.
2. The relief of the bottom of the oceans and seas. Brief navigation characteristics of soils.The relief of the bottom of the oceans and seas is quite diverse. Conventionally, several zones are distinguished in it, corresponding to different depths:
1. Continental or continental shoals (shelf) with depths of 0-200m - (7.6%)
2. Continental slope with depths of 200-3000m - (15.3%)
3. Ocean bed with depths of 3000-6000m - (75.9%)
4. Deep-water depressions over 6000m - (1.2%)
Continental shelf (shelf) - the shallowest part of the oceans and seas, adjacent to the continents. A navigational hazard on the shelf can be represented by certain forms of relief, such as: bank, rock, reef, shallow water, shallow water, underwater streamer, bar.
Bank- all isolated and limited area abrupt seabed rises. If the depth is less than 20 m, the bank is dangerous for navigation.
Rock it is a separate, small in area, abrupt rise of the bottom of hard rocks (basalt, granite, limestone). Debris and small rocks are called stones... Rocks and stones are surface, underwater and aboutdrying out (exposed in low water).
Reefit is a dangerous underwater or drying up of the seabed with rocky ground.
Stranded it is a vast shallow area of \u200b\u200bnon-solid soils with a depth of less than 20 m. hazardous to navigation.
Underwater braida - a narrow, long sandbank, which is an underwater continuation of the peninsula, a cape or a surface spit.
Bar, which happens:
- coastal - this is a narrow, stretched along the coastal strip of land of sand or shells, separating the lagoon from the sea;
- estuarine - this is a sandy underwater shaft in the coastal strip of the seabed in front of the river mouth.
Continental slope is a steeply inclined area of \u200b\u200bthe ocean floor (sea) located between 200-2500 m isobaths. Its relief is very complex: steep ledges, gentle steps, mountain ranges, deep narrow canyons and hollows.
Ocean bed - This is the central, largest part of the World Ocean, located at depths from 3000 to 6000 m. Its relief is also complex and varied: vast plains, mountain ranges, plateaus, hollows, depressions.
Deep sea trenches (troughs) - These are long narrow depressions of the ocean floor, with a depth of 6 to 10-11 thousand meters. The width of such troughs is no more than 20-70 km, and the length reaches several thousand kilometers. Currently, there are about 30 deep-sea depressions, the largest number of which are in the Pacific Ocean.
For navigation purposes usually use the classification of soils, which is based on the mechanical composition, as well as the holding properties of the soil.
The main types of soil are:
1. Solid slabs, individual rocks that do not hold anchors.
2. Lumps and boulders from 10 to 100 cm in size (boulders) and more (blocks).
3. Pebble soils (pebbles, crushed stone) 1-10 cm in size.
4. Gravel soils (gravel) 1-10 mm in size. The soil is incoherent, free-flowing.
Pebble and gravel soils do not hold the anchor well.
5. Sands - separately granular soil with a particle size of less than 1 mm. The soil is not coherent, loose.
6. Silty sands - predominant particles of 0.05-1 mm in size. The soil is incoherent, free-flowing.
7. Muddy sands - predominant particles with a size of 0.1-0.25 mm. The soil is weakly bound; in a dry state it crumbles easily. Sandy soils hold the anchor well.
8. Sandy silts - particles with a size of 0.01-01 mm prevail. Low viscosity.
9. Silt- - particles with a size of 0.01-0.05 mm prevail. The soil is cohesive, slightly plastic, viscous.
10. Clayey silts - particles with a size of 0.02 mm prevail. The soil is coherent, dense, plastic, viscous, sticky.
To choose the safest route when swimming in shallow water, soil maps are used, which can be of three types:
1. Navigational soil charts, on which the grounds are given only at separate points and are indicated by letters, for example, CRI - black silt, IR - silt, shell. On nautical charts, two types of letter designations have been introduced: large print indicates the nature of the sediment, and small print indicates the color of the soil and other information about it. For example: srmPsrGl - gray fine sand, gray clay.
2. Soil morphological maps give an idea of \u200b\u200bthe areal distribution of this or that soil. Certain types of soil on such maps are applied by hatching of various kinds.
3. Bathilitological maps - on which relief is plotted in the form of isobaths and sediment composition according to lithological research data. (Lithology is the study of the composition, origin, structure of rocks and the conditions of their occurrence).
The most widespread are bathylithological maps of the texture of soils, compared with the bottom relief. The soils are applied here based on the study of the relief, bottom slope angles, sediment texture and other lithological features.
Features of the development of sea coasts and coastal zone of the sea
Seaside -it is the outer boundary of the interaction of land and water surface of the seas and oceans, depicted on geographical maps by a line. In fact, we should talk about the coastal zone, i.e. about a more or less wide strip of the earth's surface, within which the interaction of land and sea (water body) takes place. The coastal zone consists of the coast itself - its surface part - and the underwater coastal slope.
As a result of the action of waves, when interacting with the lithosphere, abrasive and accumulative shores are formed.
Abrasive shore - a high, steep, receding coast of the ocean of the sea, destroyed by the action of the surf, with the development of abrasive landforms. Abrasion is the mechanical destruction of the shores of oceans, seas and lakes as a result of the activity of waves and surf.
Accumulative shore- the advancing coast of the ocean, sea, made up of sediments, brought by waves and surf.
Accumulation in geomorphology defines the general name of the processes of accumulation of loose mineral material and organic residues on the land surface and the bottom of water bodies.
The masses of clastic material in the coastal zone, transported by waves and surf, are called marine sediments... The sediment flow is characterized by power, capacity and saturation. In order to understand the processes of coastal erosion and its accumulation, it is also important to take into account the rate of inflow of material feeding the sediment flow. The sources of such income can be different. The accumulation of sediments in the zone of action of the surf the beach.
Modern sea coasts are represented by a huge variety of types associated with the fact that different sections of the World Ocean shores are at different stages of leveling, have a different character of initial dissection and a different geological structure.
The formation of accumulative shores of forms, on the one hand, and the cutting off of capes by abrasion, on the other, causes the coastline to level out. This inevitably gives the shores rugged outlines and dismemberment of the coastal land relief. There are the following most common shore types:
— fiord the shores formed by the flooding of the glacial valleys of the coastal mountainous countries. They are named so because they are characterized by fjords - narrow and long winding bays (the shores of Norway, Canada, Novaya Zemlya);
— skerry shores formed during the flooding of low glacial-denudation plains. Skerries are a collection of small rocky islands, narrow straits and bays;
— rias shores arising from the flooding of coastal sections of river valleys in mountainous countries;
— estuary banks formed as a result of flooding of river valleys of coastal plains. The resulting bays are called estuaries;
- shores dolmatinsky types arising from flooding of folded structures with a strike close to the general direction of the coast. At the same time, bizarre archipelagos of islands stretched along the general direction of the coast are formed;
- shores fault-block dissection, the formation of which is due to the flooding of tectonic depressions such as grabens, and the horst hills separating them act as capes and peninsulas.
The rarer types of ingressive shores are shores aral type,arising during the ingression of the sea in the lowering of the relief of the ash plains, as well as the coast, the configuration of which is due to volcanic activity. This is the type shallow the coast.
In the process of the formation of sea coasts of different physical nature, the factors of the dynamics of the coastal zone play an important role. Coastal dynamicsis called a set of processes and phenomena localized in it that determine its development.
The coastal zone consists of its own coast - its surface part - and an underwater coastal slope.
The part of the sea area located within the coastal zone is usually called by the seaside, or by the coast, but a strip of land on which coastal landforms have been preserved, created at a higher sea level than modern, the coast.
The shores of the seas and oceans, along with waves, are also subject to the effects of ebb and flow, which play a significant geomorphological role. The ebb and flow are periodic fluctuations in the level of the seas and oceans caused by the gravitational forces of the Earth, the Moon and the Sun. Tidal phenomena in the oceans are characterized by the following concepts:
— tide - a rise in the water level during the passage of a tidal wave;
— ebb - a drop in the water level during the passage of a tidal wave;
— change of waters - the moment of transition of high tide to low tide and vice versa;
— tidal events in the oceans - by dynamic and physicochemical processes in the waters of the seas and oceans caused by by-catch forces;
— tidal currents - currents caused by tidal waves.
The size and nature of sea by-catch depends not only on the relative positions of the Earth, the Moon and the Sun, but also on the geographical latitude, sea depth and the shape of the coastline.
Option 1
Part 1.
A1. The extreme northern point of Eurasia:
A2. Eurasia is washed by waters
a) the Pacific Ocean b) the Indian Ocean c) the Arctic Ocean
d) Atlantic Ocean.
A3. Eurasia consists of two parts of the world
a) North and South America b) Europe and Asia.
A4. The highest mountains in the world
a) Caucasus b) Himalayas c) Ural.
A5. Eurasia is in
A6. Rivers of Europe
a) Volga, Don, Dnieper, Rhine, Seine, Thames
b) Ob, Yangtze, Ganges, Indus, Amu Darya, Syrdarya, Euphrates.
A7. Which of the peninsulas of Eurasia is washed by the Atlantic Ocean
a) Kamchatka b) Taimyr c) Kola d) Iberian
A8. Select Southern European countries from the list: Italy, France, Bulgaria, Denmark, Portugal, San Marino, Poland
Part 2.
IN 1. What oceans are these seas related to?
a) Arabian Sea 1. Atlantic Ocean
b) East China Sea 2. Pacific Ocean
c) North Sea 3. Indian Ocean
d) Black Sea 4. Arctic Ocean
IN 2. Find the correspondence between the country and the peninsula on which it is located
A) Greece 1) Iberian
B) Italy 2) Hindustan
C) Thailand 3) Balkan
D) Portugal 4) Apennine
E) Turkey 5) Jutland
E) Denmark 6) Asia Minor
Part 3.
C1. Insert the blanks
Eurasia is the most …………………… continent on the planet. Here is the most ……………………. point of the Earth, Mount Chomolungma. Eurasia is washed by …………………… .. oceans. The most densely populated state is located on the territory of Eurasia …………. The largest peninsula of Eurasia is ………………….
Final test grade 7 "Eurasia"
Option 2
Part 1.
A1. The southernmost point of Eurasia:
a) metro Piai b) metro Chelyuskin c) metro Dezhnev d) metro Rocca
A2. The highest point of the Alps mountains is called
a) Mont Blanc b) Aconcagua c) Everest d) McKinley
a) Russia; b) China; c) India; d) Ukraine.
A4. The largest peninsula in Eurasia:
a) Arabian; b) Scandinavian; c) Iberian; d) Indochina.
A5. The largest country by population in Eurasia and the world:
a) India; b) Germany; To China; d) Japan.
A6. Which of the peninsulas of Eurasia is washed by the Indian Ocean
a) Apennine b) Hindustan c) Scandinavian d) Iberian
A7. Eurasia is in
a) arctic and temperate belts b) subtropical and tropical
c) in all belts - from arctic to equatorial.
A8. Choose from the list of Nordic countries: Italy, Norway, Denmark, Portugal, Finland, Germany
Part 2.
IN 1. Establish a correspondence between the extreme points of Eurasia and their location:
a) Cape Piai; 1) in the far north of Eurasia;
b) Cape Chelyuskin; 2) in the extreme south of Eurasia;
c) Cape Dezhnev; 3) in the extreme west of Eurasia;
d) Cape Roca; 4) in the extreme north of Europe;
5) in the extreme east of Eurasia.
IN 2. Find the correspondence between country and capital
A) Czech Republic 1) Paris
B) France 2) Beijing
C) China 3) Kiev
D) Ukraine 4) Berlin
E) Germany 5) Prague
Part 3.
C1. Insert blanks
Eurasia is located in ………………… ... climatic zones of the northern hemisphere, but most of the mainland is ………………………………. climatic zone. There are huge arid areas, as well as one of the wettest places on Earth …………………… in the mountains ………………… The least amount of precipitation is observed on the …………… peninsula.
