From space, the Earth has been described as "blue marble." Do you know why? Because most of our planet is covered by the World Ocean. In fact, almost three-quarters (71%, or 362 million km²) of the Earth is ocean. Therefore, healthy oceans are vital to our planet.
The ocean is unevenly distributed between the Northern and Southern Hemispheres. contains about 39% of the landmass, and in the Southern Hemisphere the lands occupy approximately 19%.
When did the ocean appear?
Of course, the ocean arose long before the advent of humanity, so no one knows exactly how it happened, but it is believed that it was formed due to water vapor present on Earth. As the Earth cooled, this water vapor eventually evaporated, formed clouds, and fell as rain. Over time, rain flooded the lowlands, creating the first oceans. As water flowed from land, it picked up minerals, including salts, which formed salt water.
Meaning of the ocean
The ocean is extremely important to humanity and the entire Earth, but some things are more obvious than others:
- Provides food.
- Provides oxygen through tiny organisms called phytoplankton. These organisms produce approximately 50-85% of the oxygen we breathe and also store excess carbon.
- Regulates the climate.
- It is a source of important products we use in cooking, including thickeners and stabilizers.
- Provides opportunities for recreation.
- Contains such as natural gas and oil.
- Provides a "road" for international trade. More than 98% of US foreign trade occurs across the ocean.
How many oceans are there on planet Earth?
Map of all the oceans and continents of the Earth
The main part of the hydrosphere of our planet is considered to be the World Ocean, which connects all the oceans. There are currents, winds, tides and waves that constantly circulate around this ocean. But to simplify, the world's oceans were divided into parts. Below are the names of the oceans with a brief description and characteristics, from largest to smallest:
- Pacific Ocean: is the largest ocean and is considered the largest geographical feature on our planet. It washes the western coast of America and the eastern coast of Asia and Australia. The ocean extends from the Arctic Ocean (in the north) to the Southern Ocean surrounding Antarctica (in the south).
- Atlantic Ocean: is smaller than the Pacific Ocean. It is shallower than the previous one and is bounded by America in the west, Europe and Africa in the east, the Arctic Ocean in the north, and connects with the Southern Ocean in the south.
- Indian Ocean: is the third largest ocean. It is bounded by Africa in the west, Asia in the north and Australia in the east, and is connected to the Southern Ocean in the south.
- Southern or Antarctic Ocean: was designated as a separate ocean by the International Hydrographic Organization in 2000. This ocean includes the waters of the Atlantic, Pacific and Indian Oceans, and it surrounds Antarctica. In the north it does not have clear outlines of islands and continents.
- Arctic Ocean: this is the smallest ocean. It washes the northern coasts of Eurasia and North America.
What does sea water consist of?
The salinity (salt content) of water varies in different parts of the ocean, but averages around 3.5%. To recreate sea water at home, you need to dilute a teaspoon of table salt in a glass of water.
However, the salt in seawater is different from table salt. Our table salt is made up of the elements sodium and chlorine, and salt in seawater contains more than 100 elements, including magnesium, potassium and calcium.
Ocean water temperatures can vary greatly and range from -2 to +30°C.
Ocean zones
As you study marine life and habitats, you will learn that different marine organisms can live in different areas, but the two main ones are:
- Pelagic zone (pelagil), considered the "open ocean".
- The benthic zone (benthal), which is the ocean floor.
The ocean is also divided into zones based on how much sunlight each receives. There is a plant that receives enough light to ensure the process of photosynthesis. In the dysphotic zone there is only a small amount of light, and in the aphotic zone there is no sunlight at all.
Some animals, such as whales, sea turtles and fish, can occupy multiple zones throughout their lives or during different seasons. Other animals, such as barnacles, are able to remain in one area for almost their entire lives.
Ocean habitats
Ocean habitats range from warm, shallow, light-filled waters to deep, dark, cold areas. The main habitats are:
- Littoral zone (littoral): This is a coastal area that is flooded with water during high tides and dried out during low tides. Marine life here faces serious challenges, so living organisms must adapt to changes in temperature, salinity and moisture.
- : another habitat for organisms along the coast. These areas are covered with salt-tolerant mangroves and provide important habitat for several marine species.
- Sea herbs: They are flowering plants that grow in marine, fully saline environments. These unusual marine plants have roots with which they attach themselves to the bottom and often form “meadows.” The seagrass ecosystem is capable of supporting hundreds of species of organisms, including fish, shellfish, worms and many others. Grasslands store more than 10% of the oceans' total carbon, as well as produce oxygen and protect coastal areas from erosion.
- : coral reefs are often called the "forest of the sea" due to their high biodiversity. Most coral reefs are found in warm tropical and subtropical areas, although deep-sea corals exist in some cold habitats. One of the most famous coral reefs is.
- Deep sea: Although these cold, deep and dark areas of the ocean may seem inhospitable, scientists have proven that they support a wide range of marine life. These are also important areas for scientific research, as about 80% of the ocean is more than 1,000 meters deep.
- Hydrothermal Vents: They provide a unique, mineral-rich habitat that is home to hundreds of species, including organisms called (which carry out the process of chemosynthesis) and other animals such as clams, clams, mussels, crabs and shrimp.
- Kelp forests: they are found in cold, fertile and relatively shallow waters. These underwater forests include an abundance of brown algae. The giant plants provide food and shelter for a huge number of marine species.
- Polar Regions: located near the polar circles of the Earth, north of the Arctic and south of the Antarctic. These areas are cold, windy and have wide variations in daylight throughout the year. Although these areas are apparently uninhabitable for humans, they are characterized by rich marine life, and many migratory animals travel to these areas to feed on krill and other prey. Polar regions are also home to iconic animals such as polar bears (in the Arctic) and penguins (in Antarctica). The polar regions are coming under increasing scrutiny due to concerns about temperature rises likely to be most noticeable and significant in these areas.
Facts about the oceans
Scientists have studied the surfaces of the Moon, Mars and Venus better than the ocean floor of the Earth. However, the reason for this is not at all indifference to oceanography. It is actually more difficult to study the surface of the ocean floor, measuring gravitational anomalies and using sonar at close ranges, than the surface of a nearby moon or planet, which can be done using a satellite.
Needless to say, Earth's ocean is unexplored. This complicates the work of scientists and, in turn, does not allow the inhabitants of our planet to fully understand how powerful and important this resource is. People need to understand their impact on the ocean and the ocean's impact on them—humanity needs ocean literacy.
- The Earth has seven continents and five oceans, united into one World Ocean.
- The ocean is a very complex object: it hides mountain ranges with more volcanoes than on land.
- The fresh water used by humanity directly depends on sea water, through.
- Throughout geological time, the ocean dominates the land. Most rocks found on land were deposited underwater when sea levels were higher than they are today. Limestone and siliceous shale are biological products that formed from the bodies of microscopic marine life.
- The ocean forms the coast of continents and islands. This happens not only during hurricanes but also with constant erosion, as well as with the help of waves and tides.
- The ocean dominates the world's climate, driving three global cycles: water, carbon and energy. Rain comes from evaporated seawater, carrying not only water, but also solar energy that brought it from the sea. Ocean plants produce most of the world's oxygen, and currents carry heat from the tropics to the poles.
- Life in the oceans has allowed the atmosphere to receive oxygen since the Proterozoic eon, billions of years ago. The first life arose in the ocean, and thanks to it, the Earth retained its precious supply of hydrogen, locked in the form of water, and not lost in outer space, as it otherwise would have been.
- The diversity of habitats in the ocean is much greater than on land. Likewise, there are larger groups of living organisms in the ocean than on land.
- Most of the ocean is desert, with estuaries and reefs supporting the world's largest number of living organisms.
- The ocean and people are inextricably linked. It provides us with natural resources, and at the same time can be extremely dangerous. From it we extract food, medicine and minerals; trade also depends on sea routes. Most of the population lives near the ocean, and this is the main recreational attraction. Conversely, storms, tsunamis and changes in water levels threaten residents of coastal areas. But, in turn, humanity has a negative impact on the ocean, as we continuously use it, change it, pollute it, etc. These are issues that concern all countries and all inhabitants of our planet.
- Only between 0.05% and 15% of our ocean has been studied in detail. Since the ocean makes up approximately 71% of the Earth's surface, this means that most of our planet is still unknown. As our dependence on the ocean continues to grow, marine science will become increasingly important to maintaining the health and value of the ocean, not just to satisfy our curiosity and needs.
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The Pacific Ocean is the largest on Earth
Pacific Ocean- the largest ocean in terms of area and depth on Earth, it occupies 49.5% of the surface of the World Ocean and holds 53% of the volume of its water. Located between the continents of Eurasia and Australia in the west, North and South America in the east, Antarctica in the south.
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. The greatest depth of the Pacific Ocean (and the entire World Ocean) is 10,994 m (in the Mariana Trench).
On November 28, 1520, Ferdinand Magellan entered the open ocean for the first time. He crossed the ocean from Tierra del Fuego to the Philippine Islands in 3 months and 20 days. All this time the weather was calm, and Magellan called the ocean Quiet.
The second largest ocean on Earth after the Pacific Ocean, occupying 25% of the surface of the World Ocean, with a total area of 91.66 million km² and a volume of water of 329.66 million km³. The ocean is located between Greenland and Iceland in the north, Europe and Africa in the east, North and South America in the west, and Antarctica in the south. Greatest depth - 8742 m (deep-sea trench - Puerto Rico)
The name of the ocean first appears in the 5th century BC. e. in the works of the ancient Greek historian Herodotus, who wrote that “the sea with the pillars of Hercules is called Atlantis.” The name comes from the myth known in Ancient Greece about Atlas, the Titan holding the firmament on his shoulders at the westernmost point of the Mediterranean. The Roman scientist Pliny the Elder in the 1st century used the modern name Oceanus Atlanticus - “Atlantic Ocean”.
The third largest ocean on Earth, covering about 20% of its water surface. Its area is 76.17 million km², volume - 282.65 million km³. The deepest point of the ocean is located in the Sunda Trench (7729 m).
In the north, the Indian Ocean washes Asia, in the west - Africa, in the east - Australia; in the south it borders on Antarctica. The border with the Atlantic Ocean runs along the 20° meridian of eastern longitude; from Quiet - along 146°55’ 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 ancient Greeks called the western part of the ocean known to them with the adjacent seas and bays the Erythraean Sea (Red). Gradually, this name began to be attributed only to the nearest sea, and the ocean was named after India, the country most famous at that time for its wealth on the ocean shores. So Alexander the Great in the 4th century BC. e. calls it Indicon pelagos - “Indian Sea”. Since the 16th century, the name Oceanus Indicus - Indian Ocean, introduced by the Roman scientist Pliny the Elder back in the 1st century, has been established.
The smallest ocean on Earth, located entirely in the northern hemisphere, between Eurasia and North America.
The ocean area is 14.75 million km² (5.5% of the area of the World Ocean), the volume of water is 18.07 million km³. The average depth is 1225 m, the greatest depth is 5527 m in the Greenland Sea. Most of the bottom relief of the Arctic Ocean is occupied by the shelf (more than 45% of the ocean floor) and the underwater margins of continents (up to 70% of the bottom area). The ocean is usually divided into three vast water areas: the Arctic Basin, the North European Basin and the Canadian Basin. Due to the polar geographical position, the ice cover in the central part of the ocean remains throughout the year, although it is in a mobile state.
The ocean was identified as an independent ocean by the geographer Varenius in 1650 under the name Hyperborean Ocean - “Ocean in the extreme north.” Foreign sources of that time also used the names: Oceanus Septentrionalis - “Northern Ocean” (Latin Septentrio - north), Oceanus Scythicus - “Scythian Ocean” (Latin Scythae - Scythians), Oceanes Tartaricus - “Tartar Ocean”, Μare Glaciale - “Arctic Sea” (lat. Glacies - ice). On Russian maps of the 17th - 18th centuries the names are used: Sea Ocean, Sea Ocean Arctic, Arctic Sea, Northern Ocean, Northern or Arctic Sea, Arctic Ocean, Northern Polar Sea, and the Russian navigator Admiral F. P. Litke in the 20s of the XIX century centuries called it the Arctic Ocean. In other countries the English name is widely used. Arctic Ocean - "Arctic Ocean", which was given to the ocean by the London Geographical Society in 1845.
By decree of the USSR Central Executive Committee of June 27, 1935, the name Arctic Ocean was adopted as corresponding to the form already used in Russia since the beginning of the 19th century, and close to earlier Russian names.
The conventional name for the waters of the three oceans (Pacific, Atlantic and Indian) surrounding Antarctica and sometimes unofficially identified as the “fifth ocean”, which, however, does not have a clearly delineated northern border by islands and continents. The conditional area is 20.327 million km² (if we take the northern boundary of the ocean to be 60 degrees south latitude). Greatest depth (South Sandwich Trench) - 8428 m.
Using the given characteristics, create “calling cards” of the oceans and enter the numbers of the corresponding proposals in the table.quiet.Indian.Atlantic.North.Arctic.
1) THIS OCEAN IS CALLED GREAT
2) THE NORTHERN PART IS WASHED BY THE EURASIA CONTINENT.
3) IN THIS OCEAN THERE IS A COLD PERUVIAN CURRENT.
4) THE OCEAN WAS NAMED BY FERNAND MAGELLAN.
5) THE NATURE OF THE OCEAN IS VERY HARSH.
6) THE WARMEST OCEAN ACCORDING TO SURFACE WATER TEMPERATURE
7) THE GOLF STREAM IS THE MOST FAMOUS CURRENT IN THIS OCEAN.
8) PRODUCES MOST OF THE WORLD'S FISH CATCH
9) THIS OCEAN OCCUPIES ALMOST 1/3 OF THE EARTH'S SURFACE
10) THE MAIN HEAT BRINGS TO THE OCEAN IS THE NORTH ATLANTIC CURRENT.
11) IN THE WEST THE OCEAN WASHES EURASIA IN THE EAST AMERICA.
12) THIS OCEAN IS MAINLY LOCATED IN THE SOUTHERN HEMISPHERE.
13) THERE ARE ALMOST NO CURRENTS IN THIS OCEAN.
14) LONGEST FROM NORTH TO SOUTH.
15)MOST OF THE YEAR THE ENTIRE SURFACE IS COVERED WITH ICE.
16) THIS OCEAN IS CONNECTED WITH THE ARCTIC OCEAN BY THE BERING STRAIT.
17) ONE OF THE OCEAN SEA HAS THE HIGHEST SALTINITY IN THE WORLD.
18) THIS IS THE MAIN WATERWAY ON EARTH.
19) THE COLDEST OCEAN.
20) THE DEEPEST OCEAN.
21) THE MOST POLLUTED OCEAN BY HUMAN.
22) THE WESTERN PART WASHES AFRICA.
23)SECOND BIGGEST WINDOW.
24) IN THE NORTHERN AND SOUTHERN PARTS OF THE OKEN THE HIGHEST WAVES ARE MARKED AND TYPHOONS OFTEN OCCUR.
25) THE SHALLOWEST OCEAN.
26) HAS A RICH OIL DEPOSIT ON THE PERSIAN GULF SHELF.
! ADD 4 CHARACTERISTICS YOURSELF
a) southern latitude and eastern longitude;
b) northern latitude and eastern longitude;
c) northern latitude and western longitude.
2)The extreme northern point of Russia is the cape:
a) Chelyuskin;
b) Outbuildings;
c) Dezhnev.
3) The easternmost point of Russia has a longitude:
a) western;
b) eastern;
c) northern.
4) Russia’s maritime borders, compared to land borders, have the following length:
a) big;
b) equal;
c) less.
5) The presence of three climatic zones on the territory of Russia is explained by the large extent of the country:
a) from north to south;
b) from west to east.
6) The seas of the Arctic Ocean compared to the seas of the Pacific Ocean:
a) deeper;
b) the same in depth;
c) less deep.
7)The terminal ports of the Northern Sea Route are:
a) Murmansk and St. Petersburg;
b) St. Petersburg and Vladivostok;
c) Vladivostok and Murmansk,
8) Time within the same time zone is called:
a) local;
b) waist;
c) maternity leave.
9) The boundaries of time zones are drawn in accordance with: a) parallels;
b) meridians;
c) horizontal.
10) In Russia, the last people to celebrate the New Year are:
a) Anadyr;
b) Magadan;
c) Kaliningrad.
11) There are no points on the territory of Russia that have:
a) northern latitude;
b) southern latitude;
c) western longitude.
12)The extreme eastern point of Russia is:
a) Cape Dezhnev;
b) Ratmanov Island;
c) Cape Chelyuskin.
13) The land borders of Russia compared to the sea borders have the following length:
a) big;
b) the same;
c) less.
14) The presence of climatic regions within climatic zones is explained by the large extent of Russia in the direction:
a) from north to south;
b) from west to east.
15) Salinity of the seas of the Pacific Ocean, compared to the seas of the Arctic Ocean:
a) higher;
b) the same;
c) below.
16) The time of this meridian is called:
a) local;
b) waist;
c) maternity leave.
17) A new day in Russia begins with the time zone:
a) second;
b) eleventh;
c) first.
18) The local time of a point depends on its:
a) geographic latitude;
b) geographic longitude.
19) The Northern Sea Route passes through the seas:
a) Atlantic and Pacific oceans;
b) the Pacific and Arctic oceans;
c) the Arctic and Atlantic oceans.
20) The territory of Russia is washed by as many oceans as the territory:
a) Brazil;
b) Canada;
in Australia.
21. The area of Russia is:
a) 17.1 million km2;
b) 22.4 million km2;
c) 17.8 million km2.
22. Northernmost continental point:
a) Cape Dezhnev;
b) Cape Fligeli;
c) Cape Chelyuskin. 23. Latitude of the extreme eastern point:
a) 170° W. d.;
b) 170° E. d.
24. Russia intersects:
a) with the equator;
b) with the northern tropic;
c) with the Arctic Circle.
25. The longest border between Russia and the state: a) Mongolia;
b) China;
c) Kazakhstan;
d) Ukraine.
26. Which rivers do the Russian border run along:
a) along the Amur;
b) along the Terek;
c) according to Ussuri;
d) along the Kura.
27. With which country does Russia’s border begin on the shores of the Barents Sea:
a) with Finland;
b) with Norway;
c) with Estonia.
28. What part of the territory of Russia is located behind S.P.K.?
a) 1/5 (20%);
b) 1/2 (50%); c) 1/4 (25%).
29. With which countries does Russia only have a maritime border?
a) USA; b) China;
c) Japan; d) Norway.
30. Russia is located:
a) in the northern and western hemispheres;
b) in the northern and eastern hemispheres;
c) in the northern, eastern and western hemispheres;
d) only in the northern hemisphere.
31. The seas washing Russia do not freeze:
a) Chernoe and Kara;
b) Barents and Chernoe;
c) Okhotsk and Japanese.
32. The easternmost point of Russia is located:
a) in the Western Hemisphere;
b) in the eastern hemisphere.
33. The northernmost point of Russia is located:
a) in the Severnaya Zemlya archipelago;
b) in the Spitsbergen archipelago; c) in the Franz Josef Land archipelago.
34. Find a match:
Extreme points of Russia:
a) northern; 1) m. Dezhneva;
b) southern; 2) m. Chelyuskin;
c) western; 3) the city of Bazarzyuzu;
d) eastern; 4) sand spit (Curonian) west of Kaliningrad.
35. Russia has only a maritime border with the states:
a) Norway and Japan;
b) Japan and China;
c) Japan and the USA.
36. In the north, Russia is washed by the seas:
a) Beloe, Barentsevo, Kara;
b) Beringovo, Kara, Laptev;
c) Baltic, Black, White.
37. The largest and deepest sea off the coast of Russia
a) Okhotsk;
b) Barentsev;
c) Beringovo;
d) Japanese.
38. The shallowest sea on Earth and the smallest sea in Russia
a) Azovskoe;
b) Aral;
c) White;
d) Baltic
1. Seas of the Arctic Ocean.
2. Seas of the Pacific Ocean.
3. Seas of the Atlantic Ocean
4. Caspian Sea-lake.
Seas of the Arctic Ocean
The seas of the Arctic Ocean include: the Barents Sea, the White Sea, the Kara Sea, the Laptev Sea, the East Siberian Sea and the Chukchi Sea.
All these seas wash the territory of Russia from the north. All seas, except the White Sea, are marginal, and the White Sea is internal. The seas are separated from each other by archipelagos of islands - natural boundaries, and where there is no clear boundary between the seas, it is drawn conditionally. All seas are shelf seas and therefore shallow, only the northern waters of the Laptev Sea extend to the edge of the Nansen Basin (depth 3385 m). Thus, the Laptev Sea is the deepest of the northern seas. The second deepest of the northern seas is the Barents Sea, and the shallowest is the East Siberian Sea, the average depth of all seas is 185 m.
The seas are open, and there is a free exchange of water between them and the ocean. From the Atlantic, warm and salty waters flow into the Barents Sea in two powerful streams: the Spitsbergen and North Cape currents. In the east, the Arctic Ocean basin is connected to the Pacific Ocean by the narrow Bering Strait (its width is 86 km, depth 42 m), so water exchange with the Pacific Ocean is noticeably difficult.
The seas of the Arctic Ocean are characterized by large runoff from the mainland; about 70% of the runoff of the Russian territory belongs to the basin of this ocean. The influx of river water reduces the salinity of the seas to 32‰. Near the mouths of large rivers, salinity drops to 5‰, and only in the north-west of the Barents Sea does it approach 35‰.
The climate of the seas is harsh, which is primarily due to their geographical location in high latitudes. All seas, except the White Sea, lie in the Arctic. This fact causes them to become very cold in winter, during the polar night. In the eastern part, the Arctic pressure maximum is formed, which maintains frosty, partly cloudy weather in winter. The Icelandic and Aleutian lows have a certain influence on the climate of the northern seas. The western regions of the Arctic in winter are characterized by cyclonic activity, which is especially pronounced in the Barents Sea: frosts soften, the weather is cloudy, windy, with snowfalls, and fog is possible. An anticyclone dominates over the central and eastern seas, so average January temperatures change as follows (in the direction from west to east): over the Barents Sea in January temperatures are -5o -15oC, and in the Laptev Sea and East Siberian Sea the average January temperature is about -30oC . Over the Chukchi Sea it is a little warmer - about -25°C, this is influenced by the Aleutian minimum. In the area of the North Pole in January the temperature is about -40°C. Summer is characterized by continuous solar radiation during the long polar day.
Cyclonic activity weakens somewhat in summer, but air temperatures remain quite low, because... The bulk of solar radiation is spent on melting ice. Average July temperatures vary from 0°C on the northern edge of the seas to +5°C on the coast of the continent, and only over the White Sea in summer the temperature reaches +10°C.
In winter, all seas, with the exception of the western edge of the Barents Sea, freeze. Most of the ocean is covered with ice all year round; this ice remains for several years and is called pack ice. Ice is in constant motion. Despite its considerable thickness (up to 3 m or more), the ice is subject to fractures, and cracks and even polynyas form between the ice floes. The surface of the pack ice is relatively flat, but in some places hummocks up to 5-10 m high can appear. In addition to ice, icebergs that have broken off from the cover glaciers that are present on the Arctic islands can be found in the seas. In summer, the ice area decreases, but even in August, drifting ice floes can be seen in the seas off the coast. The ice regime changes annually; now, with climate warming, there is an improvement in ice conditions (for sea vessels). The water temperature remains low all year round: in summer +1o +5o (in the White Sea up to +10o), in winter -1-2oC (and only in the western part of the Barents Sea about +4oC).
The bioproductivity of the northern seas is low, the flora and fauna of these seas are relatively poor, and the depletion of flora and fauna occurs in the direction from west to east, due to the severity of the climate. Thus, the ichthyofauna of the Barents Sea includes 114 species of fish, and 37 species live in the Laptev Sea. The Barents Sea is inhabited by: cod, haddock, halibut, sea bass, herring, etc. The eastern seas are dominated by salmon (nelma, pink salmon, chum salmon, salmon), whitefish (omul, vendace) and smelt.
Pacific Seas
The seas of the Pacific Ocean include: the Bering Sea, the Sea of Okhotsk, and the Sea of Japan. They wash the eastern shores of Russia. The seas are separated from the Pacific Ocean by ridges of islands: the Aleutian, Kuril and Japanese, behind which there are deep-sea trenches (the maximum depth at the Kuril-Kamchatka trench is 9717 m). The seas are located in the subduction zone of two lithospheric plates: the Eurasian and the Pacific. The seas are also located in the zone of transition of the continental crust to the oceanic crust; the shelf is small, so the seas of the Pacific Ocean are significantly deep. The deepest (4150 m) and largest in size is the Bering Sea. On average, the depth of all three seas is 1350 m, which is significantly deeper than the seas of the Arctic Ocean. The seas stretch for almost 5,000 km from north to south, while they have free water exchange with the Pacific Ocean. A distinctive feature of these seas is the relatively small influx of river water into them. Less than 20% of the water flow from the territory of Russia belongs to the Pacific Ocean basin.
The climate of the seas is largely determined by the monsoon circulation, which smoothes out the climatic differences of the seas, especially in winter. The average air temperature in January varies from -15-20°C near the coast and to -5°C near the island arcs. The harshest winter is in the Sea of Okhotsk (500 km from Oymyakon). In summer, the climatic differences between the seas are more noticeable. In the Bering Sea, the average temperature in summer is +7 +10° C, and in the Sea of Japan the temperature reaches +20° C. In the summer season, typhoons often sweep over the Sea of Japan. In winter, ice forms in the seas: the Sea of Okhotsk freezes completely, and the Bering and Japanese Seas freeze only near the coasts. In winter, the water temperature ranges from +2оС to -2оС, and in summer the water temperature varies from +5оС in the north to +17оС in the south. Water salinity varies from 30‰ in the Sea of Okhotsk to 33‰ in the Bering and Sea of Japan.
The seas of the Pacific Ocean are characterized by tidal currents; in Penzhinskaya Bay the highest tidal waves are observed off the coast of Russia - up to 13 m; near the Kuril Islands the height of tidal waves is up to 5 m.
The organic world of the seas is quite rich; plankton and seaweed grow abundantly in shallow waters. The ichthyofauna is represented by arctic and boreal fish species, and in the Sea of Japan also by subtropical fish species. In total, about 800 species of fish live in the seas of the Far East, of which more than 600 are in the Sea of Japan. Of commercial importance are salmon (chum salmon, pink salmon, coho salmon, chinook salmon, etc.), willow herring, and Pacific herring, and bottom fish include flounder, halibut, cod, as well as pollock and sea bass; in more southern parts - mackerel, conger eels, tuna and sharks. In addition, the Pacific seas are rich in crabs and sea urchins; fur seals and sea otters live on the islands.
Seas of the Atlantic Ocean
Seas of the Atlantic Ocean: Baltic Sea, Black Sea, Azov Sea.
These seas are inland, they wash small areas of the country. The connection between these seas and the ocean is rather weak, and therefore their hydrological regime is unique.
The Baltic Sea (Varyazhskoye) is the westernmost of the seas of Russia. It is connected to the ocean through the shallow Denmark Strait and the shallow North Sea. The Baltic Sea itself is also shallow; it was formed in the Quaternary and was covered with continental ice to the bottom. The sea is shallow, the maximum depth of the Baltic Sea is 470 m (south of Stockholm), in the Gulf of Finland the depth does not exceed 50 m.
The climate of the Baltic Sea is formed under the influence of the western transfer of air masses from the Atlantic. Cyclones often pass through the sea; annual precipitation exceeds 800 mm. Temperatures in summer over the Baltic are + 16-18°C, water temperature + 15-17°C. In winter, thaws dominate the sea; the average temperature in January is around 0°C, but with the invasion of Arctic air masses, the temperature can drop to -30°C. Only the Gulf of Finland freezes in winter, but in some severe winters the entire sea can freeze.
About 250 rivers flow into the Baltic Sea, but 20% of the river flow is brought by the Neva River. The salinity of water in the Baltic Sea does not exceed 14‰ (the average oceanic 35‰), off the coast of Russia (in the Gulf of Finland) the salinity is 2-3‰.
The Baltic fauna is not rich. Of commercial importance are: sprat, herring, eel, smelt, cod, whitefish, and lamprey. In addition, the sea is home to seals, whose numbers have recently been declining due to pollution of sea waters.
The Black Sea is the warmest of the Russian seas. It is almost equal in area to the Baltic Sea, but greatly exceeds it - due to its great depth - in volume: the maximum depth of the Black Sea is 2210 m. The Black Sea is connected to the Atlantic through a system of inland seas and straits.
The climate of the Black Sea is close to the Mediterranean (warm, wet winters and relatively dry, hot summers). In winter, northeast winds dominate over the sea. When cyclones pass, stormy winds often occur; The average air temperature in winter ranges from 0°C off the coast of Russia to +5°C on the southern coast of the sea. In summer, northwest winds prevail, the average air temperature is +22-25°C. Many rivers flow into the sea, the Danube giving the largest flow. The salinity of the Black Sea waters is 18-22‰, but near the mouths of large rivers the salinity decreases to 5-10‰.
Life lives only in the upper layers of the sea, because... Below 180 m, poisonous hydrogen sulfide is dissolved in water. The Black Sea is home to 166 species of fish: Mediterranean species - mackerel, horse mackerel, sprat, anchovy, tuna, mullet, etc.; freshwater species - pike perch, bream, ram. Pontic relics have been preserved here: beluga, stellate sturgeon, sturgeon, herring. Dolphins and seals live in the Black Sea among mammals.
The Sea of Azov is the smallest sea in Russia and the shallowest in the world: its average depth is 7 m, and its greatest depth is 13 m. This sea is a shelf sea, it is connected to the Black Sea by the Kerch Strait. Due to its small size and deeply inland position, the sea has the features of a continental climate rather than a marine one. The average air temperature in January is about -3°C, but with stormy winds from the north-east, the temperature can drop to -25°C, although very rarely. In summer, the air over the Sea of Azov warms up to +25°C.
Two large rivers flow into the Sea of Azov: Don and Kuban, which bring over 90% of the annual river flow. In addition to these rivers, about 20 other small rivers flow into it. Water salinity is about 13‰; By August the water in the sea warms up to +25°C, and near the coast up to +30°C. In winter, most of the sea freezes; ice formation begins in December, in the Taganrog Bay. The sea is freed from ice only in April.
The organic world of the Azov Sea is diverse: it is home to about 80 species of fish, mainly Mediterranean and freshwater species - sprat, anchovy, pike perch, bream, sturgeon, etc.
Caspian sea-lake
The Caspian Sea belongs to an internal closed basin; it is a relict lake, but in the Neogene it was connected with the World Ocean. The Caspian Lake is the largest lake on Earth; in terms of its hydrological regime and large size, it is very similar to the sea.
The Caspian basin consists of three parts: northern – shelf, with depths up to 50 m; medium – with depths of 200-800 m; the southern one is deep-sea, with a maximum depth of 1025 m. The length of the Caspian Sea from north to south is 1200 km, from west to east – about 300 km.
The climate of the Caspian Sea varies from temperate in the north to subtropical in the south. In winter, the sea is under the influence of the Asian High, and north-easterly winds blow over it. The average air temperature ranges from -8°C in the north to +10°C in the south. The shallow northern part is covered with ice from January to March.
In summer, clear, hot weather prevails over the Caspian Sea, the average summer air temperature is +25-28°C. The annual precipitation over the Northern Caspian Sea is about 300 mm, and in the southwest it falls up to 1500 mm.
More than 130 rivers flow into the sea, but 80% of the river flow comes from the Volga River. Water salinity ranges from 0.5‰ in the north to 13‰ in the southeast.
The organic world of the Caspian Sea is not rich, but endemic; it is home to herring, gobies, sturgeon (beluga, stellate sturgeon, sterlet, sturgeon), carp, bream, pike perch, roach and other fish species, as well as seal.