Which oceans do these seas belong to? The world's oceans include

Option 1

Part 1.

A1. Northernmost point of Eurasia:

A2. Eurasia is washed by waters

a) Pacific Ocean b) Indian Ocean c) 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, Syr Darya, Euphrates.

A7. Which Eurasian peninsula 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 do these seas belong 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

AT 2. Match the country and the peninsula on which it is located

A) Greece 1) Iberian

B) Italy 2) Hindustan

B) Thailand 3) Balkan

D) Portugal 4) Apennine

D) Türkiye 5) Jutland

E) Denmark 6) Asia Minor

Part 3.

C1. Fill in the blanks

Eurasia is the most ………………… continent on the planet. This is where the most …………………… is located. 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 7th grade “Eurasia”

Option 2

Part 1.

A1. Southernmost point of Eurasia:

a) m. Piai b) m. Chelyuskin c) m. Dezhneva d) m. Rocca

A2. The highest point of the Alps is called

a) Mont Blanc b) Aconcagua c) Everest d) McKinley

a) Russia; b) China; c) India; d) Ukraine.

A4. The largest peninsula of Eurasia:

a) Arabian; b) Scandinavian; c) Iberian; d) Indochina.

A5. The largest country in Eurasia and the world by population:

a) India; b) Germany; To China; d) Japan.

A6. Which Eurasian peninsula is washed by the Indian Ocean?

a) Apennine b) Hindustan c) Scandinavian d) Pyrenees

A7. Eurasia is in

a) arctic and temperate zones b) subtropical and tropical

c) in all zones - from the Arctic to the equatorial.

A8. Select Northern European countries from the list: 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 far west of Eurasia;

d) Cape Roca; 4) in the far north of Europe;

5) in the extreme east of Eurasia.

AT 2. Match the country and capital

A) Czech Republic 1) Paris

B) France 2) Beijing

B) China 3) Kyiv

D) Ukraine 4) Berlin

D) Germany 5) Prague

Part 3.

C1. Fill in the blanks

Eurasia is located in the …………………... climatic zones of the northern hemisphere, but most of the continent is occupied by ……………………………………. climate zone. There are huge dry areas here, as well as one of the wettest places on Earth, a place ………………… in the mountains ………………… The least rainfall is observed on the ………………… peninsula.

Our Earth appears to be a blue planet from space. This is because ¾ of the surface of the globe is occupied by the World Ocean. He is united, although greatly divided.

The surface area of ​​the entire World Ocean is 361 million square meters. km.

Oceans of our planet

The ocean is the water shell of the earth, the most important component of the hydrosphere. Continents divide the World Ocean 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 magnitude, it is enough to say that the Pacific Ocean can easily accommodate all the continents and islands combined. This is probably why it is often called the Great Ocean.

The Pacific Ocean owes its name to F. Magellan, who crossed the ocean under favorable conditions during his trip around the world.

The ocean has an oval shape, its widest part is located near the equator.

The southern part of the ocean is an area of ​​calm, light winds and a stable atmosphere. To the west of the Tuamotu Islands, the picture changes dramatically - here is an area of ​​storms and squalls that turn into fierce hurricanes.

In the tropical region, the waters of the Pacific Ocean are clean, transparent and have a deep blue color. A favorable climate developed near the equator. The air temperature here is +25ºC and practically does not change throughout the year. Winds are moderate and often calm.

The northern part of the ocean is similar to the southern part, as if in a mirror image: in the west there is unstable weather with frequent storms and typhoons, in the east there is peace and quiet.

The Pacific Ocean is the richest in the number of animal and plant species. Its waters are home to over 100 thousand species of animals. Almost half of the world's fish catch is caught here. The most important sea routes are laid through this ocean, connecting 4 continents at once.

. occupies an area of ​​92 million square meters. km. This ocean, like a huge strait, connects the two poles of our planet. The Mid-Atlantic Ridge, famous for the instability of the earth's crust, runs through the center of the ocean. 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 influenced by trade winds. There are no cyclones here, so the water here is calm, clean and clear. Closer to the equator, the Atlantic changes completely. The waters here are muddy, especially along the coast. This is explained by the fact that large rivers flow into the ocean in this part.

The northern tropical zone of the Atlantic is famous for its hurricanes. Two major 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 ​​the ocean is dangerous for shipping.

. (76 million sq. km) is an area of ​​ancient civilizations. Navigation began to develop here much earlier than in other oceans. The average depth of the ocean is 3700 meters. The coastline is slightly 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 because there are far fewer rivers flowing into it. But thanks to this, they are famous for their amazing transparency and rich azure and blue color.

The northern part of the ocean is a monsoon region; typhoons often form 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. Maximum depth - 5527m.

The central part of the bottom is a continuous intersection of mountain ranges, between which there is a huge basin. The coastline is heavily dissected by seas and bays, and in terms of the number of islands and archipelagos, the Arctic Ocean ranks second after such a giant as the Pacific Ocean.

The most characteristic part of this ocean is the presence of ice. The Arctic Ocean remains the most poorly studied to date, since research is hampered by the fact that most of the ocean is hidden under ice cover.

. . The waters washing Antarctica combine signs. Allowing them to be separated into a separate ocean. But there is still debate about what should be considered boundaries. If the borders from the south are marked by the mainland, then the northern borders are most often drawn at 40-50º south latitude. Within these limits, the ocean area is 86 million square meters. km.

The bottom topography is indented by underwater canyons, ridges and basins. 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 several billion years old. Its prototype is the ancient ocean Panthalassa, which existed when all the continents were still a single whole. Until recently, it was assumed that the ocean floors were level. But it turned out that the bottom, like the land, has a complex topography, with its own mountains and plains.

Properties of the world's oceans

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 takes much longer to heat up, but it also consumes heat more slowly than air, while having high heat capacity.

But not all water in the oceans has the same temperature. Under the sun, only surface waters heat up, and with depth the temperature drops. It is known that at the bottom of the oceans the average temperature is only +3ºC. And it remains this way due to the high density of water.

It should be remembered that the water in the oceans is salty, which is why it freezes not at 0ºC, but at -2ºC.

The degree of salinity of waters varies depending on latitude: in temperate latitudes the waters are less salty than, for example, in the tropics. In the north, the waters are also less saline due to the melting of glaciers, which greatly desalinize the water.

Ocean waters also vary in transparency. At the equator the water is clearer. As you move away from the equator, water becomes more quickly saturated with oxygen, which means more microorganisms appear. But near the poles, due to low temperatures, the waters become clearer again. Thus, the waters of the Weddell Sea near Antarctica are considered the most transparent. 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 its size. Oceans are much larger, and seas are often only part of the oceans. Seas also differ from the ocean to which they belong by a unique hydrological regime (water temperature, salinity, transparency, distinctive composition of flora and fauna).

Ocean climate

Pacific climate Infinitely diverse, the ocean is located in almost all climatic zones: from equatorial to subarctic in the north and Antarctic in the south. There are 5 warm currents and 4 cold currents circulating in the Pacific Ocean.

The greatest amount of precipitation falls in the equatorial belt. The amount of precipitation exceeds the share of water evaporation, so the water in the Pacific Ocean is less salty than in others.

Atlantic Ocean Climate determined by its large extent from north to south. The equator zone is the narrowest part of the ocean, so the water temperature here is lower than in the Pacific or Indian.

The Atlantic is conventionally divided into northern and southern, drawing the border along the equator, with the southern part being much colder due to its proximity to Antarctica. Many areas of this ocean are characterized by dense fogs and powerful cyclones. They are strongest near the southern tip of North America and in the Caribbean Sea.

For formation 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 causes a decrease in water temperature in the southern part of the ocean. Frequent hurricanes and storms occur north and south of the equator.

Formation climate of the Arctic Ocean determined by its geographical location. Arctic air masses dominate here. Average air temperature: from -20 ºC to -40 ºC, even in summer the temperature rarely rises above 0ºC. But the ocean waters are warmer due to constant contact with the Pacific and Atlantic oceans. Therefore, the Arctic Ocean warms a significant part of the land.

Strong winds are rare, but fog is common 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. The Antarctic climate prevails here with low temperatures, cloudy weather and gentle winds. Snow falls throughout the year. A distinctive feature of the Southern Ocean climate is high cyclone activity.

The influence of the ocean on the Earth's climate

The ocean has a tremendous influence on climate formation. It accumulates huge reserves of heat. Thanks to the oceans, the climate on our planet becomes softer 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 circulation of air masses. And such an important natural phenomenon as the water cycle provides the land with a sufficient amount of moisture.

The Ocean (ancient Greek Ὠκεανός, on behalf of the ancient Greek deity Ocean) is the largest body of water, part of the World Ocean, located among the continents, possessing 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 ​​the world's oceans, which includes oceans and seas, accounts for about 71 percent of the Earth's surface (about 361 million square kilometers). The bottom topography of the Earth's oceans is generally 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. At the same time, the expressions Oceanus Germanicus (“German Ocean”) or Oceanus Septentrionalis (“North Ocean”) denoted the North Sea, and Oceanus Britannicus (“British Ocean”) denoted the English Channel.

Modern definition of oceans

The World Ocean is a global volume of sea water, the main part of the hydrosphere, constituting 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, gulfs, straits, etc.

Some sources divided the World Ocean into four parts, others into five. From 1937 to 1953, five oceans were distinguished: the Pacific, Atlantic, Indian, Arctic and Southern (or Southern Arctic) ocean. The term “Southern Ocean” appeared many times back in the 18th century, when systematic exploration of the region began. In publications of the International Hydrographic Organization, the Southern Ocean was separated from the Atlantic, Indian and Pacific in 1937. There was a justification for this: in its southern part, the boundaries between the three oceans are very arbitrary, while at the same time, the waters adjacent to Antarctica have their own specifics, and are also united by the Antarctic Circumpolar Current. However, later they abandoned the distinction of a separate Southern Ocean. In 2000, the International Hydrographic Organization adopted a division into five oceans, but this decision has not yet been ratified. The current definition of oceans from 1953 does not include the Southern Ocean.

In the table below, in addition to the seas belonging to the oceans, the seas belonging to the Southern Ocean are also indicated.

Brief characteristics of the oceans

The Pacific Ocean (or Great Ocean) is the largest ocean in terms of 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 Ocean, and in the south, with the Atlantic and Indian Oceans. Occupying 49.5% of the surface of the World Ocean and containing 53% of the volume of water in 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 seas is 179.7 million km2, the average depth is 3984 m, the volume of water is 723.7 million km3 (without 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 International Date Line runs across the Pacific Ocean approximately along the 180th meridian. The study and development of the Pacific Ocean began long before the written history of mankind. Junks, catamarans and simple rafts were used to navigate the ocean. The 1947 expedition on the balsa log raft Kon-Tiki, led by the Norwegian Thor Heyerdahl, proved the possibility of crossing the Pacific Ocean westward from central South America to the islands of Polynesia. Chinese junks made voyages along the ocean shores into 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 coast of the United States (from the Los Angeles area to the San Francisco area), the coast of Japan and South Korea. The role of the ocean in the economic life of Australia and New Zealand is significant.

The second largest ocean on Earth after the Pacific Ocean, the name comes from the name of the Titan Atlas (Atlas) in Greek mythology or from the legendary island of Atlantis. It extends from subarctic latitudes all the way to Antarctica. The border with the Indian Ocean runs along the meridian of Cape Agulhas (20°E to the coast of Antarctica (Donning 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 the Drake Passage, from Oste Island to Cape Sterneck. 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 Island to Cape Brewster, through the Denmark Strait to Cape Reydinupyur on the island of Iceland, along its coast to Cape Gerpir, then to the Faroe Islands, further to the Shetland Islands and along 61° north latitude to the coast of the Scandinavian Peninsula.The area of ​​the seas, 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 ​​coastal seas is small and does not exceed 1% of the total 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 (Puerto Rico Trench). The average annual salinity of ocean waters is about 35 ‰. The Atlantic Ocean has a highly 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 to the north, Africa to the west, Australia to the east and Antarctica to 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° meridian of eastern longitude; from Quiet - along the 147° meridian of eastern longitude.

The northernmost point of the Indian Ocean is located at approximately 30°N 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 (English Arctic Ocean, Danish Ishavet, Norse and Nynorsk Nordishavet) is the smallest ocean on Earth by area, located between Eurasia and North America.

The area is 14.75 million km2, that is, slightly more than 4% of the entire area of ​​the 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 the oceans, with an average depth of 1,225 m (the greatest depth is 5,527 m in the Greenland Sea).

Formation of the oceans

Today, there is a version in scientific circles that the ocean appeared 3.5 billion years ago as a consequence of degassing of magma and subsequent condensation of atmospheric vapor. Most modern ocean basins arose in the last 250 million years as a result of the breakup of an ancient supercontinent and the divergence of lithospheric plates to the sides (the so-called spreading). The exception is the Pacific Ocean, which is a shrinking remnant of the ancient Panthalassa Ocean.

Bathymetric position

Based on the bathymetric position and nature of the relief on the ocean floor, the following 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 sea trenches - depth below 6000 m

Ocean and atmosphere

The ocean and atmosphere are fluid media. 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 warms up more slowly in summer and cools down more slowly in winter. This makes it possible to smooth out temperature fluctuations on land adjacent to the ocean.

The atmosphere receives from the ocean a significant part of the heat supplied to it and almost all the water vapor. The steam rises, condenses, forming clouds, which are carried by the winds and fall as rain or snow on land. Only surface waters of the ocean participate in heat and moisture exchange. Internal ones (about 95%) do not participate in the exchange.

Chemical composition of water

The ocean contains an inexhaustible source of chemical elements, which are contained in its water, as well as in deposits located on the bottom. There is a constant renewal of mineral deposits, through the fall or introduction to the bottom of various sediments and solutions from the earth's crust.

The average salinity of sea water is 35 ‰. The salty taste of water is given by the 3.5% dissolved minerals it contains - 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 diverse, especially in the tropical and subtropical zones between the coasts of Asia and Australia, where vast areas are occupied by coral reefs and mangroves. Phytoplankton in the Pacific Ocean consists primarily of microscopic single-celled algae, numbering about 1,300 species. In the tropics, fucus algae, large green algae, and especially the famous red algae are especially common, which, along with coral polyps, are reef-forming organisms.

The flora of the Atlantic is distinguished by species diversity. The water column is dominated by phytoplankton, consisting of dinoflagellates and diatoms. At the height of their seasonal bloom, the sea off the coast of Florida turns bright red, and a liter of seawater contains tens of millions of single-celled plants. The bottom flora is represented by brown (fucus, kelp), green, red algae and some vascular plants. Zostera, or eelgrass, grows in river mouths, and in the tropics green algae (caulerpa, valonia) and brown algae (sargassum) predominate. The southern part of the ocean is characterized by brown algae (Fucus, Lesonia, Electus). 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, fur seals) and ocean birds. Tropical latitudes are home to sea urchins, coral polyps, sharks, parrotfish and surgeonfish. Dolphins are often found in Atlantic waters. The cheerful intellectuals of the animal kingdom willingly accompany ships large and small - 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 incredibly diverse. The tropical region is distinguished by the richness of plankton. The unicellular algae Trichodesmium (a type of Cyanobacterium) 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 that glow at night: peridines, some types of jellyfish, ctenophores, and tunicates. Brightly colored siphonophores are abundant, including poisonous phasalia. In temperate and arctic waters, the main representatives of plankton are copepods, eufuazides and diatoms. The most numerous fish of the Indian Ocean are coryphens, tunas, nototheniids and various sharks. Among reptiles there are several species of giant sea turtles, sea snakes, and among mammals there are cetaceans (toothless and blue whales, sperm whales, dolphins), seals, and elephant seals. Most cetaceans live in temperate and subpolar regions, where intensive mixing of waters creates favorable conditions for the development of planktonic organisms. The flora of the Indian Ocean is represented by brown (sargassum, turbinaria) and green algae (caulerna). The calcareous algae lithothamnia and halimeda also develop luxuriantly, which participate together with corals in the construction of reef structures. Typical for the coastal zone of the Indian Ocean is the phytocenosis formed by mangroves. For temperate and Antarctic waters, the most characteristic are red and brown algae, mainly from the fucus and kelp groups, porphyry, and gelidium. Giant macrocystis are found in the polar regions of the southern hemisphere.

The reason for the poverty of the organic world of the Arctic Ocean is harsh climatic conditions. The only exceptions are the North European Basin, the Barents and White Seas with their extremely rich flora and fauna. The ocean flora is represented mainly by kelp, fucus, ahnfeltia, and in the White Sea - also zostera. The seabed fauna of the eastern Arctic, especially the central part of the Arctic basin, is extremely poor. There are more than 150 species of fish in the Arctic Ocean, including a large number of commercial fish (herring, cod, salmon, scorpionfish, flounder and others). Seabirds in the Arctic lead a predominantly colonial lifestyle and live on the shores. Mammals are represented by seals, walruses, beluga whales, whales (mainly minke and bowhead whales), and narwhals. Lemmings are found on the islands, and arctic foxes and reindeer cross the ice bridges. The polar bear, whose life is mainly associated with drifting ice, pack ice or coastal fast ice, should also be considered a representative of the ocean fauna. Most animals and birds all year round (and some only in winter) are white or very light in color.

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The world's oceans cover about 70% of the surface of our planet. Thus, it is a shell of water stretched over almost the entire surface of the Earth. The world's oceans are continuous and wash land areas on all sides, be they continents or islands.

These very land areas divide the world's oceans into 4 huge parts, which are called oceans. Each of them has its own characteristics, and, of course, its own name: the Atlantic Ocean, the Indian Ocean, the Pacific Ocean, the Arctic Ocean. In addition, there is also a fifth ocean - the Southern Ocean, which is slightly different from the rest. They are studied by the science of oceanology.

Some parts of the world's oceans are separated from it by land or underwater terrain. 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 salty lake, which may not have clear boundaries, but simply merge into the ocean in some places.

Also an important part of the World Ocean are bays and straits.

As we already know, water washes the continents from all sides. And not everywhere the coastline is a flat strip. There are many areas where seas and oceans protrude quite deeply 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, straits are water spaces that connect neighboring water basins (and their parts), and at the same time sandwiched between two parts of land.

Phenomena in the World Ocean

1. In some places there are cracks on the ocean floor. Various substances leak through them: methane, hydrogen sulfide and others. After this, the substances are mixed 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 differences in temperature and salinity of water, as well as complex bottom topography. Such waterfalls are huge masses of denser water that rush down sharply and replace less dense water. There are less than a dozen known underwater waterfalls, although there can be hundreds of them.

3. The depths of the ocean can be recognized using acoustic sounding (sound waves). In the mid-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 that this “bottom” either rises to the surface or sinks deeper. 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 very large luminous areas appear in the oceans. They are called the milky seas. It is believed that this glow occurs due to luminescent bacteria, but it is too early to say for sure.

5. Ocean currents are streams of water moving in the World Ocean along certain routes. By transporting huge masses of water, they have a great influence on the formation of the world's climate.

This is especially true for the coastal parts of continents.

The living world of the oceans

The oceans are today 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 you 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 research shows that this is only a tenth. Thus, one can only imagine what the remaining 2 million species of organisms are. What incredible animals hide in the ocean depths? If we rely on already known information, our imagination can take us very far.

Most deep-sea fish (those living at depths greater than 1 km) have relatively small eyes (or no eyes at all) because almost no light reaches them. 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 that’s why, by the way, most deep-sea fish are quite small. The big ones simply won’t be able to feed themselves. But they are small, but they can eat more than they weigh, which is why their belly becomes very bloated. Can you imagine such swallows? They also know how to fish, no matter how strange it may sound. Not in the literal sense, of course. These fish lure their victims, attract them, and then eat them.

Conclusion

The world's oceans are an unknown, mysterious underwater world. All we know about him is a pitiful crumb of knowledge. And that's great! After all, many incredible discoveries await us ahead, we just need to make a little effort.

Under the world's oceans refers to the water space 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% of the total surface is under the oceans, and 39.3% of the total surface is under the continents; in the southern hemisphere, 80.9% and 19.1%, respectively.

The world's oceans are divided into 4 oceans:

Pacific, Atlantic, Indian and Arctic.

Isolated parts of the oceans that jut into land are called seas.

According to the classification of Yu.M. Shokal Sea are divided into Mediterranean and peripheral.

Mediterranean the seas are in turn divided into intercontinental(Mediterranean Sea), located between two continents (Africa, Europe) and inland(Baltic, White) seas.

Outlying The seas (Bering, Okhotsk, Japan, 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 are called parts of the oceans and seas that protrude into the land and gradually decrease in width and depth. Depending on their shape, they are called: lip, bay, lagoon, fjords, etc.

Lip these are sea bays that extend far into the land, into which large rivers usually flow (Onega Bay, Ob Bay).

Estuaries This is the mouth of a river valley or gully flooded by the sea as a result of some subsidence of the land.

Bay called a small bay whose mouth width is less than the bay itself (Gelyandinsay Bay, Sovetskaya Gavan, Sevastopolskaya, Tsemesskaya, etc.)

Lagoon- these are internal shallow reservoirs of ring-shaped islands (attons) or parts of the seas, completely or partially separated from the sea by a spit.

Fiord– it is a narrow, long, winding bay with high and steep shores, separated by an underwater threshold from the depths of the sea.

Fjords are characteristic of the Norwegian coast.

Strait it is a relatively narrow body of water that separates land masses and connects two large water basins.

2. The topography of the bottom of oceans and seas. Brief navigation characteristics of soils. The bottom topography of the oceans and seas is quite diverse. Conventionally, several zones are distinguished in it, corresponding to different depths:

1. Continental or continental shelf (shelf) with depths of 0–200 m – (7.6%)

2. Continental slope with depths of 200-3000m - (15.3%)

3. Ocean bed with depths of 3000-6000m - (75.9%)

4. Deep-sea depressions over 6000m - (1.2%)

Continental shoal (shelf)- the shallowest part of the oceans and seas adjacent to the continents. Navigational hazards on the shelf can be posed by certain relief forms such as: a bank, a rock, a reef, shallow water, a shoal, an underwater spit, a bar.

Jar– all isolated and limited area sharp rises of the seabed. At a depth of less than 20 m, the bank is dangerous for navigation.

Rock this is a separate, small in area, sharp elevation of the bottom made of hard rocks (basalt, granite, limestone). Hard rock fragments and small rocks are called stones. Rocks and stones are surface, underwater and O drying out (exposed at low water).

Reef This is an underwater or drying elevation of the seabed with rocky soil that is dangerous for swimming.

Stranded This is a vast area of ​​shallows made of soft soils with depths of less than 20 m. They are dangerous for navigation.

Underwater spit a - a narrow, long sandbank, which is an underwater continuation of the peninsula, cape or surface spit.

Bar, which happens:

— coastal is a narrow alluvial strip of land made of sand or shells stretched along the shore, separating the lagoon from the sea;

— estuary 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 ​​the ocean (sea) bottom located between 200-2500 m isobaths. Its relief is very complex: steep ledges, gentle steps, mountain ranges, deep narrow canyons and basins.

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, basins, depressions.

Deep-sea depressions (trenches)- these are long narrow depressions of the ocean floor, having a depth of 6 to 10-11 thousand m. The width of such trenches 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 located in the Pacific Ocean.

For navigation purposes Soil classification is usually used, which is based on the mechanical composition, as well as the holding properties of the soil.

The main types of soils are:

1. Solid slabs, isolated rocks that do not hold anchors.

2. Blocks and boulders ranging in size from 10 to 100 cm (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 incohesive and loose.

Pebble and gravel soils do not hold an anchor well.

5. Sands– separately granular soil with a particle size of less than 1 mm. The soil is not cohesive, loose.

6. Silty sands – the predominant particles are 0.05-1 mm in size. The soil is incohesive and loose.

7. Silty sands– the predominant particles are 0.1-0.25 mm in size. The soil is weakly cohesive and crumbles easily when dry. Sandy soils hold an anchor well.

8. Sandy silts– particles with a size of 0.01-01 mm predominate. Viscosity is insignificant.

9. Ily— - particles of 0.01-0.05 mm in size predominate. The soil is cohesive, slightly plastic, viscous.

10. Clayey silts– particles with a size of 0.02 mm predominate. The soil is cohesive, dense, plastic, viscous, sticky.

To choose the safest route when swimming in shallow water, use soil maps, which can be of three types:

1. Navigation soil maps, on which soils are given only at individual points and are designated by letters, for example chrI - black silt, IR - silt, shell. Two types of letter designations have been introduced on nautical charts: large font indicates the nature of the sediment, and small font 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 ​​the areal distribution of a particular soil. Certain types of soils on such maps are marked with various types of shading.

3. Bathilitological maps - on which the relief is plotted in the form of isobaths and the composition of the sediment according to lithological research. (Lithology is the study of the composition, origin, structure of rocks and the conditions of their occurrence).

The most common are bathylithological maps of the mechanical composition of soils, compared with the bottom topography. The soils here are applied based on a study of the relief, bottom inclination angles, mechanical composition of sediment and other lithological features.

Features of the development of sea coasts and coastal zones of the sea

Coast - this is the outer boundary of the interaction of land and the water surface of the seas and oceans, depicted on geographical maps by a line. In reality, 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 (reservoir) 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 interacting with the lithosphere, abrasive and accumulative shores are formed.

abrasive shore- a high, steep, retreating coast of the sea ocean, destroyed by the action of the surf, with the development of abrasive forms of relief. Abrasion represents 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 shore of the ocean, sea, composed of sediment brought by waves and surf.

Accumulation in geomorphology, defines the general name for the processes of accumulation of loose mineral material and organic residues on the surface of land and the bottom of reservoirs.

Masses of debris in the coastal zone, transported by waves and surf flow, are called marine sediments. The sediment flow is characterized by power, capacity and saturation. To understand the processes of coastal erosion and its accumulation, it is also important to take into account the intensity of the supply of material feeding the sediment flow. The sources of such income may be different. The accumulation of sediment in the zone of action of a breaking stream is called beach.

Modern seashores are represented by a huge variety of types, due to the fact that different sections of the coasts of the World Ocean are at different stages of leveling, have different natures of initial dissection and different geological structures.

The formation of accumulative shores of forms, on the one hand, and the cutting off of capes by abrasion, on the other, determines the leveling of the coastline. This inevitably gives the coasts jagged outlines and dismemberment of the coastal land relief. The most common types of banks are:

— fiordaceae shores formed as a result of the flooding of glacial valleys in coastal mountainous countries. They are named so because they are characterized by fiords - narrow and long winding bays (the coasts 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 banks created by flooding of coastal sections of river valleys in mountainous countries;

— estuary banks formed as a result of flooding of river valleys of the coastal plains. The resulting gulfs are called estuaries;

- shores Dolmatinsky type that arise during the flooding of folded structures that have a strike close to the general direction of the coast. In this case, bizarre archipelagos of islands stretched along the general direction of the coast are formed;

- shores fault-block dissection, the formation of which is caused by the flooding of tectonic depressions such as grabens, and the horst hills separating them act as capes and peninsulas.

Rarer types of invasive shores are shores Aral type, arising during sea ingression in the lowering of the relief of ash plains, as well as shores, the configuration of which is due to volcanic activity. This is the type shallow shores.

In the process of formation of sea coasts of different physical natures, a large role is played by factors of the dynamics of the coastal zone. Dynamics of the coastal zone is the set of processes and phenomena localized in it that determine its development.

The coastal zone consists of its own shore - its surface part - and an underwater coastal slope.

The part of the sea area located within the coastal zone is usually called seaside or coastal, and a strip of land on which coastal relief forms created at a higher sea level than the modern one have been preserved, coast.

The shores of seas and oceans, along with waves, are also subject to the influence of tides, which play a significant geomorphological role. Ebbs and flows are periodic fluctuations in the level of seas and oceans caused by the gravitational forces of the Earth, Moon and Sun. Tidal phenomena in the World Ocean are characterized by the following concepts:

— the tide– rising water levels during the passage of a tidal wave;

— low tide– a drop in water level during the passage of a tidal wave;

— changing waters– the moment of transition of high tide to low tide and vice versa;

— tidal phenomena in the World Ocean - by dynamic and physicochemical processes in the waters of the seas and oceans caused by bycatch-forming forces;

— tidal currents- currents caused by tidal waves.

The magnitude and nature of marine bycatch depends not only on the relative positions of the Earth, Moon and Sun, but also on latitude, sea depth and the shape of the coastline.