The territory of the Russian Federation is washed by three oceans. All the seas of Russia, a list of which is given in the text of the article, are interesting and special in their own way. All of them are unique and original.
Seas of Russia: list
The largest country on the planet is connected to three oceans through 12 seas, both inland and marginal. One sea of Russia does not have a direct connection with the World Ocean (except for the connection through - this is the Caspian Sea, which is drainless.
| Sea | Belonging to the ocean |
| Azov | to the atlantic ocean |
| Barents | to the Arctic Ocean |
| Baltic | to the atlantic ocean |
| White | to the Arctic Ocean |
| Beringovo | to the Pacific Ocean |
| East Siberian | to the Arctic Ocean |
| Caspian | drainless |
| Kara | to the Arctic Ocean |
| Laptev | to the Arctic Ocean |
| Okhotsk | to the Pacific Ocean |
| Black | to the atlantic ocean |
| Chukchi | to the Arctic Ocean |
| Japanese | to the Pacific Ocean |
Total - 13 seas.
Seas of the Atlantic
Seas from the pool Atlantic Ocean fight about western shores Russia. From the north it is the Baltic Sea, in the south - the Sea of Azov and the Black Sea.
They are united by such features:
- they are all inland, that is, deeply continental;
- all of them are the final seas of the Atlantic, that is, to the east of them, either the waters of another ocean, or land.
The coastline of Russia along the seas of the Atlantic is about 900 km. Baltic Sea concern the Leningrad and Kaliningrad regions. The Black and Azov Seas are washed by the shores of the Rostov Region, the Krasnodar Territory and the Crimea.
Seas of the Arctic Ocean
Some seas of Russia (the list is given above) belong to the Arctic Ocean basin. There are six of them: five of them are marginal (Chukotskoye, Kara, Laptev, East Siberian, Barents) and one is internal (Beloye).
Almost all of them are covered with ice all year round. Due to the Atlantic current, the southwest of the Barents Sea. The waters of the Arctic Ocean reach the territory of such subjects of Russia as the Murmansk region, the Arkhangelsk region, the Yamalo-Nenets Autonomous District, the Taimyr Autonomous District, the Republic of Sakha, the Chukotka Autonomous District.
Seas of the Pacific Ocean
The list of seas washing the shores of Russia from the east and belonging to the Pacific Ocean is given below:
- Beringovo;
- Japanese;
- Okhotsk.
The territories of the Chukotka Autonomous Okrug, Magadan Region, Kamchatka Region, Khabarovsk Territory, Sakhalin Region, and Primorsky Territory adjoin these seas.
warm seas
Half of the Russian seas are covered with ice all year round. There are seas that are partially covered with an ice crust for a certain period of time. The warm seas of Russia, the list of which is given below, do not freeze during the year. So, the warm seas of Russia include:
Seas of Russia: a list of unique seas
All geographical objects of the Earth are special and interesting in their own way. There are objects that are unique and unrepeatable. Of course, this is Lake Baikal, the Volga, Kamchatka geysers, the Kuril Islands and much more. The seas of Russia are also exceptional, a list of which is given below. The table shows the characteristics of some of the seas of Russia in terms of their uniqueness.
| Sea | Characteristic in terms of uniqueness |
| Azov | It is considered the most inland sea of the planet. Communication with the waters of the oceans occurs through four straits and four seas. With a depth of no more than 13.5 m, it is recognized as the shallowest sea on the planet. |
| Baltic | It is one of the most "unsalted" seas in the world. Approximately 80% of the world's amber is mined here, which is why the sea was called Amber in ancient times. |
| Barents | This is the westernmost sea of Russia from those that are beyond the Arctic Circle. It is considered the cleanest sea of all that wash the shores of Europe. |
| White | The sea, which has a small area, is the second small sea in Russia after the Sea of \u200b\u200bAzov. Washes the lands of the historical and cultural monument of Russia - |
| Beringovo | |
| Japanese | The southernmost, but not the hottest sea in Russia. Of all the seas of Russia, this one has the richest underwater world. |
We hope that the article was interesting and useful.
BALTIC SEA
Belongs to the Atlantic Ocean. The area of the water surface is 386 thousand km2, the prevailing depths are 40-100, the maximum - 459 m. The territory of Russia is washed by the waters of the southeastern part of the sea (in the area Kaliningrad region) and the waters of the southern part of the Gulf of Finland with the Neva Bay. The Neva flows into the Baltic Sea. Zapadnaya Dvina and other smaller rivers, bringing on average over 100 km2 of fresh water per year. Industrial fishing of cod, perch, sprat is developed.
SEA OF AZOV
It is located in the south of the European part of Russia, deeply cut into the land. It belongs to the inland seas, but is also connected with the World Ocean: the Kerch Strait of Azov Sea connects with the Black Sea. The area of the water area is 38 thousand km2, the depth is up to 14 m. The territory of Russia includes the eastern part of the sea adjacent to the Rostov Region 11 Krasnodar Territory. The water quality of the shallow Sea of Azov, to a greater extent than other seas, is determined by the ratio of the volumes of continental runoff and sea water, which is equal to and on average 1:8. Under the influence of winds, the flow in the Kerch Strait is variable, therefore, on average, 41 km3 / year of water flows from the Black Sea to the Azov Sea, and 66.6 km2 / year from the Azov Sea to the Black Sea. The salt regime and mineralization of the water of the Sea of Azov is the result of mixing fresh river, atmospheric and salty Black Sea waters. In the catchment area, intensive economic activity. The coal and metallurgical industries are concentrated here, about 2 million hectares of irrigated agricultural land are located, and the population density is high. In recent decades, due to the economic development of the region, the amount of river runoff has significantly decreased, irrevocable water consumption has increased, and the flow of salty Black Sea waters has increased. As a result, the average mineralization of water increased to 12-13 g/l, while biological productivity decreased at the same time.
BLACK SEA
Deeply incised into land The area of the water surface is 422 thousand km3, the average depth is 1315, sea water 555 thousand km3. Distinctive feature Black Sea - pronounced vertical stratification. The upper layer of water 10-15 m thick is saturated with oxygen, salinity is about 1.8%. A powerful benthic elephant with a thickness of 1500-1800 m has a salinity of 2.1-2.2%, is characterized by a complete absence of oxygen and a high concentration of hydrogen sulfide. Between these layers there is a water column with large differences in temperature and salinity, the vertical exchange between the upper and deep layers of water is insignificant. The length of the coastline adjacent to Russia (the coast of the Krasnodar Territory) is 400 km. Marine waters belong to the class of "moderately polluted", here the processes of eutrophication and the formation of oxygen deficiency zones are observed. The main sources of Black Sea pollution are wastewater from industrial enterprises and housing and communal services.
Seas of the Atlantic Ocean
The three inland seas of the Atlantic Ocean - the Baltic, Black and Azov - wash small areas of Russian territory. All of them protrude deeply into the mainland, and their connection with the ocean is through other seas and shallow straits. A weak connection with the ocean determines their rather peculiar hydrological regime. The western transfer of air masses has a decisive influence on the climate of the seas.
Baltic Sea the ancient Slavs called Varangian. This is the westernmost of the seas washing the shores of Russia. It is connected to the ocean through the shallow Danish Straits and the North Sea. The Baltic Sea was formed in the Quaternary in a tectonic trough that arose at the junction of the Baltic Shield with the Russian Plate. During periods of glaciation, its basin
overlapped continental ice. In the Holocene, the sea went through several lacustrine and marine stages in its development and, apparently, at a certain period of time connected with the White Sea.
The depths of the Baltic Sea are shallow. The maximum depth is south of Stockholm (470 m). In the Gulf of Finland near the coast of Russia, the depth is less than 50 m, near the Kaliningrad coast - somewhat more.
The main features of the climate of the Baltic Sea are formed under the influence of a steady transfer of temperate air from the Atlantic. Cyclones often pass through the sea, accompanied by western, southwestern and northwestern winds, cloudy weather and heavy rainfall. Their annual number reaches 800 mm and more. In summer, cyclones carry moist cool air, so the average temperature in July is 16-18°C, and the water temperature is 15-17°C. In winter, the Atlantic air causes thaws, since its average temperature in January is about 0°C. The sometimes cold arctic air breaking through here can lower the temperature to -30...-35°С. The Gulf of Finland, located near the borders of Russia, is covered with ice in winter; off the coast of the Kaliningrad region, there are only floating ice. However, in exceptionally severe winters, the entire sea froze (1710, 1809, 1923, 1941, 1955, etc.).
About 250 rivers flow into the Baltic Sea, but about 20% of the annual river runoff is brought into the sea by the river. Neva (79.8 km 3). Its flow exceeds the flow of the three other largest rivers: the Vistula, the Neman and the Daugava, combined. The flow of the Neva is regulated by lakes, so it is characterized by one spring-summer maximum. Strong prolonged westerly winds raise the water level in the eastern part of the Gulf of Finland, which caused catastrophic floods in St. Petersburg, located at the mouth of the Neva (1824, 1924). Limited water exchange with the ocean and significant river runoff determine the low salinity of sea water (2-14‰, off the coast of Russia - 2-8‰).
The fauna of the Baltic Sea is depleted in species due to high desalinization, low mixing of waters and the poverty of plankton. The following fish are of commercial importance: herring, Baltic sprat, cod, whitefish, chime, lamprey, smelt, salmon. The seal lives in the sea, the number of which is declining due to the pollution of sea waters.
Black Sea- the warmest among the seas washing the shores of our Motherland. AT ancient greece they called him Pontus Euxine which means "hospitable sea". In terms of area, it is almost equal to the Baltic, but differs sharply in volume and
depths (see table 1). The connection of the Black Sea with the ocean is carried out through a system of inland seas (Marmara, Aegean, Mediterranean) and straits (Bosphorus, Dardanelles, Gibraltar). The greatest length of the Black Sea water area from west to east reaches 1130 km, the maximum width (from north to south) is 611 km, the minimum is only 263 km.
The Black Sea lies in a deep tectonic basin with oceanic-type crust and Cenozoic sedimentary cover. The maximum depth of the sea reaches 2210 m. The depression is delineated by the continental slope, which in a number of places (especially near the Caucasian coast) is strongly dissected by submarine canyons. The shelf is most developed in the northwestern part of the sea, off the coast of Ukraine. The coastline of the sea is poorly dissected.
The geographical position of the sea and the relatively small area of the water surface determine the same type of climate throughout its water area, close to the Mediterranean, with warm, wet winters and relatively dry summers. However, the orography of the coastal territories causes some differences in the climate of individual sections of the sea, in particular, an increase in precipitation over the eastern part due to the influence of the mountainous barrier of the Caucasus.
In winter, the synoptic situation determines the predominance of northeast winds with an average speed of 7-8 m/s over almost the entire sea area. The development of strong (more than 10 m/s) and especially storm winds is associated with the passage of cyclones over the sea. The average air temperature in winter drops from high seas to the shores. In the northeastern part, near the coast of Russia, it approaches 0°С, in the northwest it is -2°С, and in the southeast + 4...+ 5°С.
In summer, northwest winds prevail over the sea. Their average speed is 3-5 m/s, decreasing from west to east. Strong, especially stormy, winds are rare in summer and are also associated with the passage of cyclones. The average air temperature in August varies from + 22°C in the northwest to 24-25°C in the east of the sea.
Numerous rivers flowing into the Black Sea annually bring 346 km 3 of fresh water into it. The Danube gives the largest runoff (201 km 3 / year). All rivers of the northwestern part discharge 270 km 3 /year of fresh water into the sea, i.e. almost 80% of the total runoff, while the rivers of the Caucasian coast bring only 43 km3. The largest runoff occurs in the spring, the smallest is observed in the fall.
On the surface of the sea along the coast there is a cyclonic current. In the central part of the sea, two rings of cyclonic currents are traced: one in the western part, the other in
in the eastern part of the sea. Along the Russian shores, the current carries water from the south. Through the straits there is an exchange of water with neighboring seas. Through the Bosporus, the surface current carries the Black Sea water, and the deep current delivers more salty and heavier water from the Sea of Marmara to the Black Sea. The salinity of the Black Sea waters in the central part is 17-18‰, and increases with depth to 22.5‰. Near the mouths of large rivers, it drops to 5-10‰.
The Black Sea is very peculiar in terms of the distribution of dissolved gases in the water column. Saturated with oxygen and therefore favorable for life here, only the upper layer to depths of 170-180 m lower bound oxygen layer to the bottom, so the deep layers of the Black Sea are devoid of life.
There are 166 species of fish in the sea. Among them there are Pontic relics (beluga, stellate sturgeon, sturgeon, herring), Mediterranean forms (mullet, mackerel, horse mackerel, red mullet, sprat, anchovy, tuna, stingray, etc.) and freshwater forms (ram, pike perch, bream). Of the mammals in the Black Sea, endemic species have survived - the Black Sea bottlenose dolphin (dolphin) and the white-bellied seal, or the monk seal, listed in the Red Books.
Sea of Azov- the smallest and shallowest on the planet. Its area is 39.1 thousand km 2, the volume of water is 290 km 3, the greatest depth is 13 m, the average is about 7.4 m. The narrow and shallow Kerch Strait connects it with the Black Sea. The Sea of Azov is a shelf. The relief of its bottom is quite simple: the shallow coast turns into a flat and flat bottom. Depths slowly and smoothly increase with distance from the coast.
The sea is deeply incised into the land, its water area and volume of water are small and do not have a significant impact on the climate; therefore, its climate is characterized by continental features, more pronounced in the northern part of the sea, which is characterized by Cold winter and hot dry summers. In the southern regions, which are more influenced by the proximity of the Black Sea, the climate is milder and more humid. The average January temperature is -2...-5°С, but with storm winds from the east and northeast directions, temperatures may drop to -25...-27°С. In summer, the air over the sea warms up to 23-25°C.
Two rivers flow into the Sea of Azov major rivers- Don and Kuban and about 20 small rivers. Don and Kuban bring into the sea over 90% annual runoff river waters, so almost all fresh water flows into the eastern part of the sea. The vast majority of the runoff
takes place during the spring and summer. Water exchange with the Black Sea takes place through the Kerch Strait. About 49 km 3 of water per year flows out of the Sea of Azov, and about 34 km 3 enters the Black Sea water, i.e. outflow to the Black Sea prevails. The salinity of sea waters in the Sea of Azov in the first half of the century was about 11‰. Then, due to a reduction in the inflow of river waters used for irrigation and an increase in the inflow of Black Sea waters, salinity began to increase and reached 13.8‰ by the beginning of the 1980s.
The shallow Sea of Azov warms up well in summer. In July - August, the average sea water temperature is 24-25°C. Maximum warming (up to 32°C) occurs near the shores. In the open sea, the temperature does not exceed 28-28.5°C. The long-term average annual water temperature on the sea surface is 11°С.
Ice forms annually in the Sea of Azov, but due to the frequent and rapid change weather conditions ice during the winter can repeatedly appear and disappear, turning from motionless to drifting and back again. Ice formation begins at the end of November in the Taganrog Bay. The final cleansing of the sea from ice occurs in March - April.
The shallowness of the sea, good warming and illumination, mixing of the water column, abundant removal of organic and mineral substances by rivers created favorable conditions for the development of organic life. About 80 species of fish live in the Sea of Azov, among which the Mediterranean forms are the most diverse. Tyulka, pike-perch, anchovy, bream, sturgeon are of the main commercial importance.
Important transport routes pass through the seas of the Atlantic Ocean. great importance in foreign trade turnover and for connections with inland ports. Here are the ice-free ports of Russia - Kaliningrad, Novorossiysk. All three seas are used for recreational purposes, especially south seas. The Black Sea coast of the Caucasus is one of the main recreational areas of Russia. Fishing is developed in all seas. Until the 1950s, the Sea of Azov was the main fishing area of our country. In recent years, fishing has taken a more modest place in the waters of the seas themselves.
The Black Sea lies in a depression within two zones of Alpine folding and separates Eastern Europe from Asia Minor. The area of the Black Sea is 423 thousand km2. Together with the Sea of Azov (38 thousand km2), which is a large bay or lagoon, the Black Sea covers an area of 461 thousand km2. The average depth of the Black Sea is 1197 m, the Sea of Azov is 8 m. The volume of water in the Black Sea reaches 537 thousand km3, and in the Sea of Azov 300 km3. The narrow and shallow Bosphorus Strait (maximum depth 27.5 m) connects the Black Sea with the Sea of Marmara and further through the Dardanelles with the Mediterranean Sea. The even shallower Kerch Strait, which is only 5 m deep, connects the Black Sea with the Sea of Azov. The wide geosynclinal area of the Black Sea is a deep-water part of the sea bed (maximum depth 2245 m), which has a flat bottom, bordered by a very steep continental slope (in some places up to 20°). In the eastern part of the Black Sea, the slope is dissected by numerous underwater canyons. The northwestern part of the Black Sea and the Sea of Azov are located within a shallow continental shelf. The maximum depth of the Sea of Azov is only 13.5 m.
Bottom relief
The western part of the Black Sea is a wide continental shelf, which, gradually narrowing to the south, stretches to the Bosporus. The continental shelf merges into the continental slope at a depth of 100–150 m. In the other coastal regions of the Black Sea, the continental shelf is either very narrow (no more than 10–15 km wide) or completely absent, since it is replaced by a narrow abrasion terrace.
Geological history
The Black Sea basin initially, in the Early Tertiary period, was formed as a median (“intermountain”) zevgogeosyncline, which sags between the mountain systems of the Crimea and the Caucasus on the one hand and the Pontic Mountains of Anatolia on the other. During the Cretaceous period, this massif was a mountainous region, from which precipitation was carried both to the north and to the south. The tectonic movements that caused the formation of the depression occurred in the Tertiary and Quaternary periods and continue to this day. Geophysical studies made it possible to determine that the earth's crust under the bed of the central part of the Black Sea basin is oceanic. There is no granite layer here. The Black Sea is a classic example of the "oceanization" of the original continental earth's crust. However, unlike the oceans, the sedimentary layer of the Black Sea reaches 10–15 km. On the continental slope, at a depth of up to 1500 m, there are terraces of fault origin with young shallow-water sediments. The continental slope zone, especially along the Crimean and Anatolian coasts, is highly seismic.
In the Quaternary period, there was also a significant uplift of mountain belts on the Black Sea coast, as evidenced by the different heights of the sea terraces formed at that time. In the Neogene, the outlines, area and salinity of the Black Sea again underwent changes. In Pontic times, it joined the Caspian Sea and turned into a vast closed lake. The Pliocene period and the evolution of the Black Sea fauna were first studied and systematized by N. I. Andrusov (1918).
The Quaternary period was also characterized by numerous changes in the level of the Black Sea associated with eustatic fluctuations in the level of the World Ocean. The latter are closely connected with the change of glacial epochs. Repeatedly, when the level of the Black Sea fell below the level of the Bosphorus, it turned into a lake and its waters were desalinated. On the other hand, at a high level of the Black Sea, the water exchange with the Mediterranean Sea became more and more active, the waters of the Black Sea became saline and it was populated by organisms requiring relatively high salinity.
Changes in the species composition of mollusks make it possible to very accurately date the sediments of the bottom of the Black Sea and its shores: the remains of mollusks found in the sediments belong to different epochs of the Quaternary period. Based on organic residues in the sediments, the New Euxinian desalinated phase of the development of the Black Sea was also studied, which, as it turned out, dates back to the last ice age(Wurm glaciation).
Deposits of this phase have been exposed in many places, both in shallow and deep waters, but they are rarely or never found on land. The level of the Black Sea (from -40 to -60 m) during this period was significantly lower than the Bosphorus Threshold. This was followed by a relatively fast Holocene transgression and salinization of the sea waters. close to modern level established about 5000 years ago.
Terraces
The most common on land are the two Karangat terraces. It has been established that their coastlines are elevated by 12–14 m in the Caucasus and by 22–25 m in Bulgaria. This was the period of a more complete connection between the Black Sea and the Sea of Marmara and the formation of the ancient Euxinian basin. During this period, many large stenohaline forms (such as mollusks, sea urchins, etc.) entered the Black Sea. Many researchers compare this period of the Black Sea with the monastic period mediterranean sea.
In the same areas, there are ancient Euxinian (55-60 m) and Uzunlar (35-40 m) terraces. They correspond to the Tyrrhenian terraces. The ancient Euxinian basin became desalinated and was dominated by Caspian relics and endemic forms.
At the turn of the Pliocene and the Quaternary, the Chaudinskaya terrace was formed. In the Crimea, its deposits are found at a height of up to 30 m, in the Caucasus up to 95-100 m, but there they are deformed under the influence of the movement of the earth's crust.
In the Sea of Azov, the terraces are poorly preserved, as the area has recently experienced intense subsidence. During the low-level periods of the Black Sea, the Sea of Azov turned into a swampy alluvial plain.
Hydrological regime
The Black Sea is typical example inland "Euxine" sea, which affects its hydrological conditions. It was found that in the lower layers, salt water (36 ind.) from the Sea of Marmara penetrates into the Black Sea, and desalinated water from the surface layer of the Black Sea enters the Sea of Marmara. According to latest research, the inflow of Mediterranean waters is 202 km3 per year, and the surface runoff carries 348 km3 of water from the Black Sea. Over 400 km3 of water is brought to the Black Sea by numerous rivers. (The inflow and outflow of water into the Black Sea are subject to slight annual fluctuations.)
Average salinity surface water layer in the central part 16~18%. At depths greater than 150–200 m, salinity increases to 21–22.5 ppm. Surface waters warm up to 25°C in summer (up to 28°C near the coast). In winter, in the open sea, they cool down to 6-8 ° C. The Sea of \u200b\u200bAzov and the northwestern part of the Black Sea are covered with ice in winter. Deep waters have a temperature of 8-9 ° C all year round.
Since surface and deep waters differ in density, their mixing is difficult. Only the upper 50-meter layer is saturated with oxygen. In the lower layers, the oxygen content decreases, and hydrogen sulfide appears at a depth of 150-200 m,
the amount of which in the bottom layers can reach 6 cm3/l. The origin of hydrogen sulfide is explained by the activity of both anaerobic bacteria that decompose protein substance and desulfuric bacteria.
An analysis of the balance of fresh and salt water in the Black Sea shows that, despite the difficulty of exchange between the upper and lower layers, such an exchange still exists. Every year up to 3000 km3 of deep water rises to the surface. The mechanism of this phenomenon is still not entirely clear.
The weak connection of the Black Sea with the ocean, abundant river flow, difficult water exchange between the upper and lower layers lead to some change chemical composition water compared to the World Ocean, namely, it contains slightly less sulfates and much more carbonates.
The movement of surface water is determined by both winds and river runoff. Generally surface water The Black Sea circulate along the coast counterclockwise.
In addition to the general circulation, there are two circular currents - east and west. On the border between them, the water moves both to the south and to the north. The speed of these currents ranges from 0.1 to 0.3 m/s. Drift currents develop in coastal areas and have a speed of up to 0.5 cm/s.
The water level in the Black Sea is subject to seasonal fluctuations up to 20 cm on average. In coastal areas, especially in the northwest, significant amplitudes of level changes are observed under the influence of wind. Tidal fluctuations in the water level (up to 8-9 cm) are completely imperceptible in comparison with fluctuations in the level under the influence of winds. In the western region, surges up to 7 m high are formed.
Biology
The bottom vegetation of the Black Sea includes 285 species of brown, red and green algae. It is mostly depleted Mediterranean flora. It should be noted the numerous flora along the rocky shores, as well as the huge banks of the Phylophora and the northwestern part of the sea. Philophora is used in Industry.
Phytoplankton is represented by 350 Mediterranean species. It is widely distributed in the open sea to depths of 100–125 m. Phytoplankton occurs off the coast to a depth of 200 m. The biomass of phytoplankton in the open sea averages 0.1 g/m3, with a sharp increase near the coast: diatoms make up to 79% of plankton. In spring, the number of phytoplankton reaches 20 million cells per liter. In summer, the number of dinoflagellates rises to 48,000 per liter.
Zooplankton includes over 70 species; its biomass in the open sea averages 0.3 g/m3. The most numerous benthic and nekton organisms are the "immigrants" of the Mediterranean Sea, which have adapted to the more "fresh" water of the Black Sea. The bays of the northwestern part of the Black Sea are inhabited by Pontic relics (Pliocene), close to the Caspian. In the Black Sea, there are also river forms that have adapted to brackish water.
Due to the low salinity of the Black Sea, its fauna and flora, and especially the fauna and flora of the Sea of Azov, are much poorer than the fauna and flora of the Mediterranean Sea. If the latter is inhabited by up to 7000 various kinds of plant and animal organisms, then only 1200 species are found in the Black Sea and approximately 100 in the Sea of Azov. Many classes of animals living in the Mediterranean Sea are not represented at all in the Black Sea (coral polyps, cephalopods and pteropods). Of the echinoderms, only small forms of holothurians and brittle stars are found. All representatives of the Black Sea benthic fauna are smaller in size than the Mediterranean ones.
The benthos biomass in the Black Sea is relatively rich near the coast. But the biomass and number of species gradually decrease starting from a depth of 5–70 m. Below 50 m, benthos is represented by the most common mollusk
At a depth of 13-180 m, benthic organisms are not found at all (except for bacteria).
The fauna of the Sea of Azov is even poorer in terms of the number of species, but in the Sea of Azov there is an intensive development of three species of mollusks, which make up the bulk of the biomass (up to 400 g/m2).
About 180 species of fish are found in the Azov-Black Sea basin. Many of them migrate from the Black Sea to the Sea of Azov and back. Fishing is highly developed, especially in the Sea of Azov. There are many dolphins in the Black Sea; seals are found.
Bottom sediments
Shell sediments are common on a wide shelf, as well as along the coasts of the northwestern part of the Black Sea and south of the Kerch Strait. The shell also composes large accumulative coastal forms (bars, bay bars and spits). Terrigenous (mussel) silt along the mountainous shores of the Black Sea occurs starting from a depth of about 20 m. Large areas of the continental slope are devoid of modern sediments. Tubes for taking soil cores bring Neo-Euxinian and Karangatian sediments or run into bedrock outcrops. Extensive areas of the bottom near the inflection of the shelf are exposed as a result of gravitational displacements of sediments. Below, mixed sediments of underwater landslides occur in many places.
In the deep part of the Black Sea basin, there are thick layers of clayey-calcareous silt with different composition and structure. Ribbon stratification of organic matter is associated with the death of planktonic organisms in summer and autumn. A layer of fine-grained calcite is deposited in winter, a thin layer of clay in spring. The thickness of the layers is hundredths or tenths of a millimeter in different areas. Microlayering makes it possible to calculate the rate of silt deposition. During 5000 years, the average accumulation of clay silt is 1 m, and lime silt is only 10-20 cm. All types of deep-sea silt contain a large number of diagenetic iron sulfide (pyrite, hydrotroilite), indicating a reducing environment.
Based on the changes in the lithological composition at the bottom of the deep-water depression, it is possible to distinguish the sediments of several phases of the development of the Black Sea up to the New Euxinian deposits. Relic water, in the thickness of sediments, has retained an exceptionally low salinity: 4 ppm. in a layer or at a depth of 6 m below the bottom surface. Layers and lenses of sand, which are obviously the result of turbidity flows, are found in the thickness of deep-sea silts along the edges of the deep-sea basin.
The coast of the Black Sea almost everywhere have simple outlines. An exception is the western Crimea, where long braids are developed. There are no big islands. Limans and lagoons of the western part of the Black Sea have a special character. They are flooded estuaries, cut off from the sea by embankments. Along the straight coasts of the western part of the Black Sea and the Caucasian coast, several powerful alongshore streams of sand and pebbles have been established.
In the Sea of Azov, the rate of abrasion of clay shores is very high - up to 4 m per year. On the northern coast of the Sea of Azov, as a result of the action of waves coming from the northeast, a series of long braids projecting into the sea at an angle of approximately 45°.
1. Seas of the Arctic Ocean.
2. Seas 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, are marginal, and the White is inland. 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 the seas are shelf - respectively, shallow, only the northern water area of the Laptev Sea comes to the outskirts of the Nansen Basin (depth 3385 m). Thus, the Laptev Sea is the deepest of northern seas. In second place in depth from the northern seas is the Barents, and the shallowest is the East Siberian, the average depth of all seas is 185 m.
The seas are open, and there is free water exchange between them and the ocean. From the Atlantic side, warm and salty waters flow into the Barents Sea in two powerful streams: the Spitsbergen and North Cape currents. In the east, the basin of the Arctic Ocean is connected to the Pacific Ocean by the narrow Bering Strait (its width is 86 km, the depth is 42 m), so water exchange with the Pacific Ocean is noticeably difficult.
The seas of the Arctic Ocean are characterized by a large runoff from the mainland, about 70% of the runoff of the territory of Russia belongs to the basin of this ocean. The inflow of river waters reduces the salinity of the seas to 32‰. Near the mouths of large rivers, salinity decreases to 5‰, and only in the northwest of the Barents Sea does it approach 35‰.
The climate of the seas is severe, which is primarily due to their geographic location at high latitudes. All seas, except for the White, lie in the Arctic. This fact causes their strong cooling in winter, during the polar night. In the eastern part, the Arctic baric maximum is formed, which in winter maintains frosty, slightly cloudy weather. The Icelandic and Aleutian lows have a certain influence on the climate of the northern seas. Cyclonic activity is typical for the western regions of the Arctic in winter, it is especially pronounced in the Barents Sea: frosts soften, it is cloudy, windy, with snowfalls, the weather is possible fogs. An anticyclone dominates over the central and eastern seas, therefore, the 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 the East Siberian Sea, the average January temperature is about -30oC . It is a little warmer over the Chukchi Sea - about -25 ° C, this is due to the influence of the Aleutian minimum. Near North Pole in January the temperature is around -40oC. Summer is characterized by continuous solar radiation during the long polar day.
Cyclonic activity in summer somewhat weakens, but air temperatures remain quite low, because. basic quantity solar radiation used to melt ice. The average temperatures in July vary from 0°C on the northern margin of the seas to +5°C on the coast of the continent, and only above the water area White Sea in summer the temperature is up to +10oC.
In winter, all seas, with the exception of the western margin of the Barents Sea, freeze over. Ice-bound all year round most of ocean, this ice persists for several years and is called pack ice. The ice is in in constant motion. Despite its considerable thickness (up to 3 m or more), the ice is prone to breaks, 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 occur. In addition to ice, icebergs can be found in the seas that have broken away from the sheet glaciers that are present on the Arctic islands. In summer, the area of ice is reduced, but even in August, drifting ice floes can be seen in the seas near the coast. The ice regime changes every year, now with the warming of the climate there is an improvement in ice conditions (for sea vessels). The water temperature remains low throughout the year: in summer +1o +5o (in the White Sea up to +10oC), 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 inhabit the Laptev Sea. Cod, haddock, halibut, sea bass, herring, etc. live in the Barents Sea. Salmonids (nelma, pink salmon, chum salmon, salmon), whitefish (omul, vendace) and smelt predominate in the eastern seas.
Seas of the Pacific Ocean
The seas of the Pacific Ocean include: the Bering Sea, the Sea of Okhotsk, 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 islands, 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: Eurasian and Pacific. The seas are also located in the transition zone of the continental crust to the oceanic, 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 much deeper than the seas of the Arctic Ocean. The seas stretch for almost 5000 km from north to south, while they have free water exchange with the Pacific Ocean. Distinctive feature of these seas is a relatively small inflow of river waters into them. The Pacific Ocean basin accounts for less than 20% of the water flow from the territory of Russia.
The climate of the seas is largely determined by the monsoon circulation, which smooths out the climatic differences of the seas, especially in winter period. The average air temperature in January varies from -15-20°C near the coast to -5°C near the island arcs. The most severe 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 summer temperature is +7 +10o C, and in the Sea of Japan, the temperature reaches +20o C. In the summer season, over Sea of Japan typhoons are frequent. In winter, ice forms in the seas: the Sea of \u200b\u200bOkhotsk freezes completely, and the Bering and Japan only near the coasts. In winter, the water temperature ranges from +2oC to -2oC, and in summer the water temperature varies from +5oC in the north to +17oC in the south. Water salinity varies from 30‰ in the Sea of Okhotsk to 33‰ in the Bering and Japan Seas.
The seas of the Pacific Ocean are characterized by tidal currents, in the Penzhina Bay the highest tidal waves are observed off the coast of Russia - up to 13 m, near the Kuril Islands tidal waves up to 5 m.
The organic world of the seas is quite rich, plankton abundantly develops in shallow waters, seaweed. The ichthyofauna is represented by arctic and boreal fish species, and in the Sea of Japan also by subtropical fish species. Total in the seas Far East about 800 species of fish live, 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.), ivasi herring, also Pacific herring, from bottom fish- flounder, halibut, cod, as well as pollock and sea bass; in the more southern parts, mackerel, conger eels, tuna and sharks. In addition, the seas of the Pacific Ocean are rich in crabs, sea urchins lives on the islands fur seal, sea otter.
Seas of the Atlantic Ocean
Seas of the Atlantic Ocean: Baltic Sea, Black Sea, Sea of Azov.
These seas are inland, they wash small areas of the country. The connection of these seas with the ocean is rather weak, and therefore their hydrological regime is peculiar.
The Baltic Sea (Varangian) is the westernmost of the Russian seas. 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 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, the annual rainfall exceeds 800 mm. Summer temperatures over the Baltic are +16-18оС, water temperature is + 15-17оС. In winter, thaws dominate the sea, the average January temperature is about 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 the Neva River brings 20% of the river flow. The salinity of water in the Baltic Sea does not exceed 14‰ (average oceanic 35‰), off the coast of Russia (in the Gulf of Finland) the salinity is 2-3‰.
The fauna of the Baltic is not rich. Commercial value are: sprat, herring, eel, smelt, cod, whitefish, lamprey. In addition, the seal lives in the sea, the number of which has recently been declining due to pollution of sea waters.
The Black Sea is the warmest of the Russian seas. In terms of area, it is almost equal to the Baltic, 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 Mediterranean (warm, humid winters and relatively dry, hot summers). In winter, northeast winds dominate the sea. When cyclones pass, storm winds often occur; the average air temperature in winter ranges from 0°C off the coast of Russia to +5°C on south coast seas. In summer, northwest winds prevail, the average air temperature is +22-25оС. Many rivers flow into the sea, the largest flow comes from the Danube. The salinity of the Black Sea waters is 18-22‰, but near the mouths of large rivers, 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 the water. 166 species of fish live in the Black Sea: 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. Of the mammals in the Black Sea, dolphins and seals live.
The Sea of \u200b\u200bAzov is the smallest sea in Russia and the shallowest in the world: its average depth is 7 m, and the largest is 13 m. This is a shelf sea, it is connected to the Black Sea by the Kerch Strait. Due to its small size and deep inland position, the sea has the features of a continental climate, and not a maritime one. The average air temperature in January is about -3°C, but with storm winds of the northeast direction, 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 more small rivers flow into it. The salinity of the waters is about 13‰; water in the sea by August warms up to + 25 ° C, off the coast to + 30 ° C. In winter, most of the sea freezes, the formation of ice begins in December, in the Taganrog Bay. The sea is freed from ice only by April.
The organic world of the Sea of Azov is diverse: about 80 species of fish live in it, mainly Mediterranean and freshwater species - sprat, anchovy, pike perch, bream, sturgeon, etc.
Caspian sea-lake
The Caspian belongs to the internal drainless basin, it is a relict lake, but in the Neogene it was connected with the World Ocean. Caspian lake- the largest lake on Earth, in terms of hydrological regime and large size, it is very similar to the sea.
The Caspian Basin consists of three parts: the northern part is shelf, with depths up to 50 m; medium - with depths of 200-800 m; southern - deep water, with a maximum depth of 1025 m. The length of the Caspian from north to south is 1200 km, from west to east - about 300 km.
The climate of the Caspian varies from temperate in the north to subtropical in the south. In winter, the sea is under the influence of the Asian high, and northeasterly winds blow over it. The average air temperature is from -8oC in the north to +10oC in the south. Shallow Northern part from January to March it is covered with ice.
In summer, clear, hot weather dominates over the Caspian, average summer temperature air + 25-28оС. The annual amount of precipitation over the water area of the Northern Caspian is about 300 mm, and in the southwest it falls up to 1500 mm.
More than 130 rivers flow into the sea, but of these, 80% of the river flow comes from the Volga River. The salinity of the water 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 inhabited by: herring, gobies, sturgeons (beluga, stellate sturgeon, sterlet, sturgeon), carp, bream, pike perch, vobla and other fish species, as well as seals.
