Presentation on the theme "Seas washing the borders of Russia" in geography for schoolchildren. Consists of twenty eight slides. Author - Ishmuratova Lilia Malikovna

Fragments from the presentation:

Targets and goals:

• Get acquainted with the peculiarities of the seas and oceans washing the territory of Russia
• Consider Natural resources seas of Russia and ecological problems seas

Arctic Ocean

Characteristics of the seas of the Arctic Ocean

• All marginal seas, except for the White
• All seas are located on the continental shelf, so they are shallow
• Salinity of seas below oceanic
• The climate of the seas is harsh, only part of the Barents Sea does not freeze
• The Northern Sea Route passes through the seas of the Arctic Ocean - the shortest route from the Baltic Sea to Vladivostok
• Ice moves clockwise under the influence of winds and currents - it drifts. Ice collide, forming piles of ice - hummocks

Pacific Ocean

Characteristics of the Pacific seas

• All the seas of the Pacific Ocean are marginal and are separated from the ocean by a chain of islands
• All have significant depths, since they have almost no shelf zone
• The seas are located in the Pacific Ring of Fire, in the border area lithospheric plates, therefore, tsunamis are frequent here, and along the shores there are volcanoes, the coast of the seas is mountainous
• The nature of the Bering and Okhotsk seas is harsh. The seas freeze, and in summer the water temperature is not higher than + 12C. Only the southernmost, the Sea of ​​Japan, does not freeze. Typhoons and violent storms are frequent here. The Sea of ​​Okhotsk has the highest tides in Russia

Atlantic Ocean

Characteristics of the seas of the Atlantic Ocean

• All seas are internal, that is, they are connected to the ocean by narrow straits and are surrounded on all sides by land
• Deep - Black Sea (maximum depth - 2210 m), and Azov - the shallowest sea in Russia - maximum depth 15 m, average 5-7 m.
• The Black Sea is located in a tectonic depression
• The Baltic and Azov seas are covered with ice for a short time. In the Baltic, bays freeze, and the Black Sea is the warmest sea in Russia and ice occurs only in its northern bays
• The Black Sea is contaminated from a depth of 200 m with poisonous hydrogen sulfide and is deprived of life from a depth of 200 m
• Caspian Sea - lake basin of internal flow

The most, the most, the most

• The deepest sea in Russia - Beringovo (maximum depth - 5500 m)
• The largest in area - Beringovo
• The shallowest - Azov (maximum depth - 15 m)
• The smallest area is Azovskoe
• The coldest - East Siberian (in summer water temperature +1 C)
• The cleanest is Chukotka
• The warmest is the Black Sea

Resources of the seas

• The Barents Sea is the richest in biological resources of the Arctic Ocean
• Richer in resources of the Pacific Ocean
• The Caspian Sea contains 80% of the planet's sturgeon stocks
• In the Baltic Sea they catch
• The Sea of ​​Azov is an important fishing area
• The Black Sea does not have an important fishing value, but fishing is also carried out here
• Kislogubskaya tidal power plant (Barents Sea)
• The seas have rich mineral resources

The Black Sea has the richest recreational resources

• Anapa
• Tuapse

The main sources of pollution of the seas

• Drains industrial enterprises supplied with river water - 40%
• Sea transport - 30%
• Accidents of oil tankers
• Accidents of oil pipelines laid along the seabed

Ways to improve the environmental situation

• Use waste-free production along the coasts and river banks
• Construction of treatment facilities
• Avoid high concentration (accumulation of industrial enterprises) on the coasts of the seas
• Creation of protected water areas (marine reserves and reserves)

Sea comparison plan

• Which ocean basin does it belong to?
• Fringe or internal
• Coastline (rugged, no, bays, peninsulas)
• Depths
• Salinity
• Water temperature (ice)
• Resources of the seas
• Ecological problems

Comparative characteristics of the Black and Kara seas

Black Sea

• Atlantic Ocean basin
• Inland sea
• Indented, Crimean Peninsula
• 1315 m
• January - 1 ° + 7 °, July + 25 °
• Recreational resources
• Ecological problems

Kara Sea

• Arctic Ocean basin
• Okrannoe
• Heavily indented, Yamal Peninsula, Gydansky, Taimyr
• 111 m
• 7-33 ‰
• January -1.5 °, July + 1 ° + 4 °
• Biological resources
• Ecological problems

a brief description of sea ​​waters

Territory Russian Federation it is washed by the waters of 12 seas belonging to three oceans, as well as by the waters of the inland Caspian Sea.

The total length of the country's maritime borders is estimated at more than 44 thousand km. The total area of ​​the sea water area falling under the jurisdiction of the Russian Federation is at least 7 million km 2. At the same time, 60% of the total river runoff goes to the marginal seas of the Arctic Ocean. Table 2.21 provides a characteristic of the seas washing the territory of Russia.

Table 2.21. Characteristics of the seas washing the territory of the Russian Federation

About 60% of the total runoff of the country's rivers flows into the marginal seas of the Arctic Ocean. The total catchment area of ​​the sea basins of this ocean in Russia is about 13 million km 2, or almost three quarters of the territory of the state.

Table 2.22 shows the water balance in Russia as a whole and in the context of the basins of some seas.

Table 2.22. Water balance in Russia as a whole and in the context of the basins of some seas

* Excluding large islands in the Arctic Ocean.

Sea water quality

Eutrophication of marine and coastal ecosystems is an unexpected new problem that no one knew about 30 years ago. Today it has become obvious that the increase in toxic phytoplankton is occurring with increasing intensity. Strong eutrophication is observed in closed and semi-closed seas, for example, in the Black Sea. Since the Stockholm Conference, changes in natural sedimentation have become one of the main threats to coastal ecosystems. Urbanization processes lead to an increase in residential and industrial areas, which, in turn, can lead to changes in natural sediment flows.

According to observations carried out by organizations of the Roshydromet system and the Ministry of Natural Resources of Russia, as well as monitoring of the state of the geological environment of the continental shelf (GMGSSH) of the North-West of Russia, carried out by the Center for Monitoring the Geological Environment of the FGUNPP "Sevmorgeo" at federal test sites in the waters of the Barents, White and Baltic Seas quality marine ecosystems are assessed as follows.

Arctic Ocean basin

Barents Sea

In general, the geoecological situation has retained its features compared to 2006. The geological and geophysical studies carried out made it possible to state that in the Barents Sea, despite the intense technogenic load, the upper horizons of the geological environment (bottom sediments and Quaternary formations of the Holocene age) are practically not disturbed. There is no pollution in most of the water area, and before the start of the stage of exploitation of oil and hydrocarbon feedstock on the Barents Sea shelf, it comes to the disposal of oilmen in a nearly pristine form.

According to measurements in 2007 in Pechora Sea, in contrast to 2006, the content of this type of pollutant increased in the bottom layer of water, which reflects an increase in the load on the marine environment of the development of land oil field Varandey (fig. 2.11).

Rice. 2.11. Change in the average content of heavy metals in the bottom water of the Pechora Sea in 2001-2007, mg / l

In bottom sediments, as well as in near-bottom waters, the content of heavy metals increased in 2007 and almost approached the level of the approximate permissible concentration (Figure 2.12).

Rice. 2.12. Change in average concentrations of heavy metals in bottom sediments of the Pechora Sea in 2002-2007, mg / g

The specific activities of the technogenic radionuclide cesium-137 are at the background level, and the increased values ​​at stations 570 and 574 are determined by the higher content of the clay fraction in the bottom sediments.

Pollution of the Kola Bay is formed under the influence of the runoff of large rivers, as well as industrial and household wastewater coming from 40 enterprises, cities and towns located on the shores of the bay. The largest volume of effluent comes from enterprises and vessels of the fishing fleet, ministries of defense, transport and municipal services.

The oxygen regime in the bay is satisfactory, the content of dissolved oxygen in the 0-bottom layer varied within 8.63-13.30 mgO 2 / dm 3. Water saturation with oxygen is good - 89-123% (2007). At the same time, the pH of sea waters ranged from 6.43 to 8.06. The total alkalinity in the waters of the bay increases from south to north as salinity increases. With depth, alkalinity increases, which is determined by the predominance of sea waters and a decrease in the effect of

The Kola Bay is at the same time a place of unloading of the terrestrial water system, an area of ​​intensive navigation, the location of a number of large civil and military ports and small parking lots.

A threatening source of oil pollution is sea transportation, which is increasing due to the redistribution of traffic volumes and an increase in its production in the Arctic regions.

In the water area of ​​the Kola Bay, especially in the water area of ​​ports, it is possible to visually detect the presence of an oil slick.

The inflow of petroleum products with wastewater, according to incomplete reports of enterprises, in the period 2002-2007. decreased from 58 to 28 tons / year, but in addition to the organized discharge, there is constant pollution of the bay from a large number of ships and various floating equipment. With a formal reduction in the supply of petroleum hydrocarbons with wastewater, their concentration in the waters of the bay tends to grow, increasing from 0.06 mg / dm 3 in 2003 to 0.35 mg / dm 3 in 2005.

A slight increase in the concentration of a number of heavy metals in the western part of the Murmansk Trench is due to their introduction from the North Cape Current from Norway and England. The increase in the concentration of petroleum hydrocarbons in bottom sediments can be unambiguously associated with the increasing intensity of tanker shipments of petroleum products.

Compared to the background values ​​of the selected heavy metals for the Barents Sea, the bottom sediments of the Kola Bay are significantly more polluted. The highest values ​​of COP above 2.0 were found in the area of ​​the commercial and fishing ports of Murmansk (stations 510, 511).

For the first time in the history of observations, the indicator of the change in the average content of heavy metals in the bottom water (mg / l) of the Kola Bay turned out to be lower than the MPC, which clearly indicates a decrease in the level of pollution with heavy metals in the water column due to a decrease in the discharge of untreated wastewater. However, this reduction is mainly achieved by reducing the content of zinc and lead.

White Sea... High and extremely high levels of pollution of the waters of the Dvina Bay were not observed during the observation period.

According to the results of hydrochemical surveys of the Dvinsky Bay, the oxygen regime was satisfactory. The content of oxygen dissolved in water averaged 9.48 mg / l with a concentration range of 6.58-11.20 mg / l. The saturation of the water masses of the bay with oxygen varied within 62-100%, the minimum value (62%) was recorded in June at station No. 12 at a depth of 10 m. Compared to the previous year, the oxygen regime did not change significantly.

Water pollution with oil products was insignificant. The average concentration was 0.03 mg / l. The maximum concentration of 0.19 mg / l (3.8 MPC) was determined in June at station No. 16 in the bottom water layer. Compared to the previous year, the level of pollution of the waters of the Dvinsky Bay with oil products has slightly decreased. The average content of nitrites was 1.0 μg / l, no excess of MPC for nitrites was noted. The maximum concentration of 3.5 µg / l was recorded in June at station No. 19 in the bottom water layer.

The results of observations in the White Sea confirmed the earlier conclusion that the geological environment of this sea basin is one of the most prosperous in the North-West of Russia. The most unfavorable from the point of view of the manifestation of exogenous processes, including pollution of bottom waters and bottom sediments are:

Kut part of the Kandalaksha Bay, where polymetallic anomalies in bottom sediments have been established, which may be associated with mineralization on the adjacent shores of the Kola Peninsula. The appearance of anomalous strontium values ​​can be considered characteristic, which is most likely associated with the transshipment of apatite in the Kandalaksha port. This is evidenced by the spatial relationship of these anomalies, the complex nature of the anomalies, where there are also increased concentrations of oil hydrocarbons and a number of heavy metals.

The mouth of the Northern Dvina, where a powerful marginal filter is in its delta, traps most of the pollutants that accumulate in the inter-island channels. Excessive masses of phenols enter the sea, forming clear jet anomalies from the mouth to the central part of the basin. Elevated concentrations of other elements were not found within the delta of the Northern Dvina.

In the Kandalaksha Bay, it was possible to document the fact of groundwater infiltration into the bottom layer of the sea basin. This indicates a broader, than previously thought, development of water exchange processes in water areas with underground horizons.

In general, the nature of the White Sea ecosystem remains stable and in terms of pollution level it is significantly cleaner than the Baltic Sea, including the Gulf of Finland, as well as certain areas of the Barents Sea. The content of oil products in the near-bottom waters of the White Sea is low (Fig. 2.13).

Rice. 2.13. Change in the content of oil products in the bottom water in the central part of the White Sea in 2001-2007, mg / l

The presence of an increased level of phenolic pollution of waters at the outlet from the Kandalaksha Bay (station 306) and above the Solovetsky Islands indicates the influence of municipal wastewaters (Fig. 2.6.4).

Rice. 2.6.4. Change in the content of phenols in the bottom water in the central part of the White Sea in 2005-2007, mg / l

In contrast to the increased average level of pollution by oil products of the entire White Sea, due to high values ​​in Onega, Dvinsky and Kandalaksha bays, in the central part in 2007 a decrease in the level of pollution is observed.

In this part of the White Sea in 2007, a decrease in the level of phenol pollution of bottom waters was observed.

The most polluted waters with heavy metals and oil products are observed at the outlet from the Kandalaksha Bay and in the central part of the White Sea. Contamination of bottom sediments with oil products is significantly below the minimum permissible level (MRL).

Laptev sea... In 2007, no observations were made of the degree of pollution of sea waters on the territory of the Republic of Sakha (Yakutia) in the system of Roshydromet and Rosvodresursy.

On the territory of the Republic of Sakha (Yakutia), observations of the waters of the Neelov Bay (the Laptev Sea) are carried out, but not as sea waters, but as a surface water body (reservoir).

Sea of ​​Okhotsk... In 2007, no observations were made of the degree of pollution of sea waters on the territory of the Magadan Region in the system of Roshydromet and Rosvodresursy.

Japanese Sea... The coastal waters of the sea are characterized by high level pollution with oil products, exceeding the maximum permissible concentration by 10 or more times. The level of pollution of sea waters with oil products increased in comparison with 2006 in the Zolotoy Rog Bay (from 3.2 to 4.8 MPC), in Diomede Bay (from 2.4 to 4.2 MPC), in the Eastern Bosphorus Strait (from 2 up to 3 MPC), in the Amur Bay (from 1.2 to 3.6 MPC). In the Ussuriisk Bay and the Nakhodka Bay, OHC pollution remained at the 2006 level and exceeded the MPC by 1.4 times. The excess of MPC by petroleum hydrocarbons was observed in 87.5% of samples from the Vostochny Bosphorus Strait; in 96% - the Golden Horn; in 93.8% - Diomede Bay; in 99.2% - in the Amur Bay; 38.9% - in the Ussuriysky Bay and 95.1% - in the Nakhodka Bay. Compared to last year, there was an increase in the average annual concentration of pesticides: DDE - 2 times in Zolotoy Rog Bay and 6 times in Nakhodka Bay, DDD - 2 times in Zolotoy Rog and Diomed Bays, Vostochny Bosphorus Strait, Nakhodka Bay and 5 times in the Ussuriysky Bay, DDT - 1.8 times in the Golden Horn Bay and in the Ussuriysky Bay. In the Amur Bay, the average annual concentration of DDT has increased by 3 times.

According to the results of a comprehensive assessment and individual hydrochemical indicators in 2007, the water quality of the Amur Bay and Diomede Bay deteriorated. The quality of the waters of the Diomid Bay moved from class IV “polluted” to class V “dirty”, and the Amur Bay - from class III “moderately polluted” to IV class “polluted”.

The quality of the waters of the Ussuriisky Bay and the Nakhodka Bay has not changed and belongs to the III class "moderately polluted". The quality of the waters of the Vostochny Bosphorus Strait still belongs to the IV class “polluted”, and the Zolotoy Rog bays - to the V class “dirty”. The pollution index of the waters of the Vostochny Bosphorus Strait and the Golden Horn Bay increased in comparison with 2006.

Atlantic Ocean basin

Baltic Sea. Russian part The Baltic Sea is divided by natural and artificial barriers into the upper (Neva Bay) and lower (eastern part of the Gulf of Finland) regions. These areas differ significantly in abiotic conditions and structural and functional characteristics of the ecosystem.

Neva Bay- the shallowest part and the most desalinated part of the Gulf of Finland. Hydrochemical and hydrophysical properties of water are determined by the influence of the river flow. Neva River and economic activities on the coastal area. The salinity of the water north of the Sea Canal was 0.07%. During 2007, in the eastern part of the Neva Bay, off the southwestern coast of Vasilievsky Island, hydrotechnical works were carried out related to the reclamation of a new territory for the construction of the Marine Passenger Terminal. As a result of hydrotechnical works associated with the reclamation of a new territory in the Neva Bay to the north and south of the Sea Canal, the water transparency has sharply decreased (in May-October 2007, in most cases, the water transparency in the larger water area of ​​the Neva Bay was only 0.3- 0.1m). The influence of these hydraulic works on the decrease in transparency and increase in water turbidity extended to the shallow water zone of the eastern part of the Gulf of Finland. The pollution of the water area of ​​the Neva Bay with heavy metals is to the greatest extent determined by the excess of MPC by copper, zinc and manganese. High BOD5 values ​​were recorded in the southern resort area. The average concentration for the year was 4.04 mgO 2 / dm 3. The highest values ​​of BOD 5, which exceeded the standard value by more than two times, were recorded in July and October. The content of total (dissolved) phosphorus was significantly lower than in previous years. The average concentration of total phosphorus for the entire water area of ​​the Neva Bay was 9 μg / dm 3 (414 samples). This may be due to the fact that in 2007 large-scale hydraulic engineering works were carried out in the Neva Bay with soil removal and the formation of a large amount of suspended particles, on which a significant amount of dissolved phosphorus was adsorbed. In 2006-2007. the waters of the Neva Bay by WPI value (1.56) are characterized as "moderately polluted", class III.

The greatest negative changes in the geological environment in 2007 occurred in the Neva Bay during the creation of a new harbor for the passenger terminal in front of Vasilievsky Island. A sharp increase in the amount of suspended material was recorded here, which led to a decrease in oxygen in the bottom layer of water and an increase in the total mineralization of waters;

In 2007, the tendency of an increase in the level of pollution of bottom sediments with oil products continued (almost 2.5 times higher than the MPL). The level of concentration of oil products in the bottom waters slightly decreased in comparison with 2006, but it was below the MPC, i.e. there was practically no pollution.

In the Russian part of the Gulf of Finland, construction sands and ferromanganese nodules are mined. The negative impact of these processes is the formation of large volumes of suspended matter in aquatic environment during their extraction, and, as a result, contamination of vast areas of the shelf with heavy metals and other pollutants.

A significantly higher level of contamination of the bottom sediments of the Gulf of Finland by the specific activity of cesium 137 is noted as compared to other seas of the north-west of Russia. At st. 93 (north of the Powerful Island) from year to year the absolute anomaly of 1150 Bq / kg remains, which is the "Chernobyl trace".

V Curonian Lagoon during the entire study period, the oxygen content was within the normal range (7.3-12.9 mg / l). Significant fluctuations in the concentration of ammonium nitrogen (0.011-0.915 mg / l) were noted. The concentration of nitrate nitrogen did not exceed the MPC. The content of oil products in the surface layer varied from 0 to 0.2 mg / l; detergents (synthetic surfactants) - from 0 to 0.07 mg / l. In 2007, the most polluted areas of the Curonian Lagoon were the southwestern and southeastern areas.

Kaliningrad (Vistula) bay- the Russian and Polish parts of the gulf, respectively. The waters of the Kaliningrad Lagoon are more exposed to the action of sea waters than the waters of the Curonian Lagoon. At the mouth of the river. Pregoli had cases of high and extremely high water pollution. The concentration of nitrite nitrogen varied in the range of 0.011-0.024 mg / l. The content of nitrate nitrogen did not exceed the MPC level. The concentration values ​​of ammonium nitrogen varied from 0.013 to 2.4 mg / L. The content of detergents in the water over the entire observation period ranged from 0.029 to 0.23 mg / l. In the Kaliningrad Bay, the most polluted areas are the mouth of the Pregolya River and the northeastern part of the Bay, on the hydrochemical regime of which the waters of the Pregolya River have a significant impact. The water at the mouth of the Pregolya River and in the northeastern part of the bay is characterized as "dirty" and "very dirty", in the rest of the bay - as "conditionally clean" and "clean".

Black Sea... In 2007, observations were made over the quality of the marine environment in the area of ​​deep-water outlets in the Anapa-Adler section. The monitoring results showed that the concentration of pollutants in seawater did not exceed the MPC. The influence of discharges from deep-water outlets on the quality of the marine environment has not been revealed.

Inland seas

Caspian Sea... In the coastal regions of the Republic of Dagestan, observations were carried out near the cities of Makhachkala, Kaspiysk, Izberbash, Derbent, in the mouths of the Terek, Sulak, Samur rivers, as well as in the open part of the Middle Caspian in the section from about. Chechnya to the Mangyshlak Peninsula. The average content of petroleum hydrocarbons (OH) in all surveyed areas varied within the range of 0.4-1.6 MPC. The maximum concentration was recorded in the area of ​​the city of Kaspiysk. Average concentrations of ammonium nitrogen did not exceed 1 MPC, phenols - 1.0-6.0 MPC. In 2007, the seaside waters of the river. The Terek was assessed as “moderately polluted”, in the area of ​​the cities of Makhachkala, Derbent, Kaspiysk, Izberbash, the coastal areas of the Sulak and Samur rivers - “polluted”.

Azov sea... In 2007, the pollution of waters and bottom sediments of the Sea of ​​Azov was the lowest since 1998, approximately at the level of 1995. The most polluted are coastal waters in areas of active economic activity and the mouths of rivers flowing into rivers.

The average salinity in the Russian part of the Azov Sea was 6.63 0/00 - at the level of 2006. In the Kerch Strait, the average annual salinity was 11.86 0/00.

Average annual values ​​of dissolved oxygen at observation points in 2007 varied within 5.52-9.47 mg / dm 3. One of the main problems was an episodic sharp decrease in oxygen content in water (on average in the Sea of ​​Azov - more than 20%). In the eastern part of the Taganrog Bay, as the shallowest water area, it led to fish "freezing". This low oxygen content was due to the extremely high temperatures in summer.

The main amounts of biogenic pollution enter watercourses with domestic wastewater, as well as in the form of surface runoff from the territories of agricultural facilities and settlements. Municipal waste water is extremely rich in phosphorus, and this is the main reason for the local accumulation of labile phosphorus compounds in areas where people and animals are concentrated. Excessive intake of phosphorus in environment causes algae bloom, which affects not only the organoleptic properties of water, but also greatly impairs the oxygen regime of the reservoir after their mass withering away.

In 2007, practically in all areas of the sea, a decrease in the content of phosphates was noted, with the exception of the Eastern region of the Taganrog Bay, where an increase in concentration was noted due to the addition of phosphates by the Don river flow (in the delta, phosphate concentrations were noted - 2-3 MPC). At a distance of 10-15 km from the delta, the concentrations decrease and do not exceed the MPC standard for phosphorus and phosphates.

The decrease in the content of phosphorus phosphates in the water of the Sea of ​​Azov is associated with its consumption by aquatic organisms, as well as the transition to bottom sediments during the formation of insoluble forms. Currently, human economic activity is the dominant factor in the formation of river runoff by phosphate compounds.

The average annual concentration of oil products in the Sea of ​​Azov has significantly decreased compared to 2006 in all regions; for the last 3 years the MPC standard has not been exceeded.

Exceeding the maximum permissible concentration (1.2-2.0 MPC) in the Sea of ​​Azov was recorded sporadically for nickel, vanadium and molybdenum.

Average annual concentrations for almost all ingredients (including those exceeding the MPC) have decreased compared to previous years of observation.

In 2007, the water pollution index (WPI) decreased in most sections due to a decrease in the concentration of oil products and most heavy metals.

Water areas near large settlements (the cities of Taganrog, Yeisk, Primorsko-Akhtarsk, Temryuk) are subject to the greatest anthropogenic impact. This is due to the removal of pollution from the waters of rivers and estuaries, polluted by discharges from rice paddies, the influx of runoff from adjacent fields and sewage from sea and fish ports, fish factories, as well as the removal of pollution from storm waters of residential areas of cities and towns. In 2007, coastal waters near large settlements The Azov region had 3 quality classes - “moderately polluted”.

Sea- a part of the ocean with its own regime, formed under the influence local conditions and free or hindered water exchange with adjacent ocean (sea) waters. The sea communicates with them directly or through straits and is separated from them by ridges of islands and underwater rises (rapids). The main feature of the sea is only its inherent hydrometeorological conditions.

The main features of the seas

The sea is a regional complex natural site. Unlike the ocean, the nature of which is mainly determined by planetary processes, the main features of the sea, due to its smaller size than the ocean, are formed under the influence of regional factors. Of these, the most significant are: geographical position, the degree of isolation of the sea from neighboring basins, river runoff, water circulation. The main features of the sea include the presence of a basin (depression), a threshold separating it from the adjacent areas of the ocean or another sea (although there are seas without these features), and independent circulation of waters.

The basin of the sea, in which all oceanological processes take place, usually has a more or less developed shelf and continental slope. The ocean floor is found only in very deep (more than 2000 m) seas. The bottom of shallow seas with depths of up to 200-300 m is the shelf, and deep (up to 2000-2500 m) - the underwater margin or the foot of the continent.

The sea is separated from the adjacent waters by the coasts of continents, islands or underwater rapids in the straits. The wider the sea is open towards the ocean, the more it is subject to its influence, which affects the climatic and hydrological parameters of the sea. Thus, the Barents Sea is noticeably different from the Siberian seas located to the east of it. It is heated by warm Atlantic waters, and most of it does not have permanent ice cover. New earth prevents the penetration of warm Atlantic waters into the Siberian seas. The same island, as well as the archipelagos of Svalbard and Franz Josef Land, block the access of the ice of the Arctic Ocean to the Barents Sea.

The more complex the connection between the sea and the ocean, the stronger the dependence natural features sea ​​from local conditions - climate and physical and geographical features of the adjacent land. Thus, the White Sea, surrounded by land on almost all sides, is more severe than the Barents Sea, located to the north and freely connected to the ocean. The Sea of ​​Okhotsk lies to the south of the Bering Sea, but colder than it, since the first of them juts deeply into the region of the Asian continent, which is strongly cooled in winter, and is "sheltered" from the warm Pacific waters by the cold Kamchatka current.

The nature and volume of water exchange between the sea and adjacent basins depend on the width and depth of the straits connecting the sea with adjacent areas. The threshold in the strait, hindering water exchange, increases the isolation of the sea, which in turn affects its hydrological conditions. Thus, the Sea of ​​Japan is isolated from the deep Pacific waters. For this reason, the water temperature in the deep layers of the Sea of ​​Japan is low. Despite the location close to the subtropics, this sea is the coldest of all the seas washing the Far Eastern shores of Russia.

The depth of the threshold to a certain extent determines the features of the vertical structure of the waters in the sea, its difference from the structure of adjacent areas of the ocean. So, in the Sulu Sea, the depth of the threshold of the deepest strait is 400 m. Ocean water with characteristics characteristic of the 400 m horizon (temperature 10.5 °, salinity 34.45-34.47 ‰) enters the sea. These indicators are observed in the sea from the horizon of 400 m to the bottom (the greatest depth of the sea is 5500 m). True, such conditions are created only in the seas, where convective mixing does not capture deep layers. If, in an isolated sea, density mixing penetrates to the bottom, then its own water mass is formed in it.

Most full definition the concept of "water mass" belongs to A.D. Dobrovolsky (1961): “A water mass should be called a certain, relatively large volume of water that forms in a certain area of ​​the World Ocean - a focus, a source of this mass, which for a long time has an almost constant and continuous distribution of physical, chemical and biological characteristics that make up a single complex and spreading as a whole. " The main indicators of the water mass are its temperature and salinity, although some other hydrochemical characteristics are often used, for example, the amount of dissolved oxygen.

The structure of sea waters is formed by various geographic types of water masses, which are formed under the influence of regional climatic factors.

Continental runoff is one of the most important factors determining the hydrological features of the sea. Its influence is most noticeable and diversely manifested in the seas isolated from the World Ocean, and in the seas with highly limited water exchange. So, due to the large river runoff, the salt composition of the Caspian Sea and the Aral Sea differs from the oceanic one by an increased content of carbonates and a lower concentration of chlorides. To a lesser extent, this is typical for Black and Azov seas(see table).

Getting into the sea, the river water reduces the salinity not only of the estuarine areas, but also of areas significantly distant from them. When salinity is less than 24.7 ‰, the water temperature at the highest density is higher than its freezing point. Such waters are called brackish, and the seas are called brackish, respectively. These include the Caspian, Black, Baltic seas. In areas of strong influence of river runoff, all other things being equal, ice formation begins earlier than in water areas with "sea" salinity (greater than 24.7 ‰).

With a larger volume of runoff, the water level at the estuary seaside slightly rises, and a runoff current is formed. For example, in the Kara Sea, abundant continental runoff (mainly the Yenisei and Ob rivers) forms a layer of water about 1.5 m thick, which creates a steady flow along the coast of Taimyr to the Severnaya Zemlya archipelago.

A significant difference in the salinity of the freshened and underlying sea waters determines the greater vertical stability of the water layers, which makes it difficult to mix them.

Despite natural differences, the seas show common features of water circulation, which are more or less influenced by local factors. In all seas, as a result of atmospheric pressure and wind, wind currents are formed in the surface layers. Due to the small size of the seas in relation to the scale of atmospheric dynamic processes strong influence the shores exert pressure on the wind currents. Bends of the coastline, protruding far into the sea, deflect the current from the direction of the wind.

In the coastal zone of many seas, there is usually a slight increase in level compared to open spaces, which contributes to the development in upper layers cyclonic circulation in the Northern Hemisphere. Depending on the local features of the sea, the circulation of water is characterized by different stability, intensity, speed of water movement, etc. In some areas, the main streams branch out, the formation of local eddies with different sizes and time of existence.

In shallow, considerably separated seas, the currents on the surface change rather rapidly in time and are determined by the synoptic situation over the sea.

The circulation of waters in the seas, widely and freely connected with the ocean, depends not only on the action of the wind, but also on the ocean currents. Water exchange through the straits has a significant effect on the nature of water circulation, even in large seas. The movement of sea waters is greatly influenced by tides, which in some cases even change the direction of the prevailing transport of waters.

There are 63 seas on the globe. The Caspian and Aral (these are huge, but still lakes are "descendants" ancient ocean Tethys), as well as Galilee and the Dead (the addition "sea" here is historical). What is the sea like? This question was answered by the classification of scientists A. M. Muromtsev, Yu. M. Shokalsky, A. V. Everling, Kryummel, N. N. Zubov. In the article, we will give the most widespread categories of the seas.

What is the sea: classification by oceans

The most famous classification is the one that distributes the seas according to their belonging to the basin of one or another ocean. Based on it, 5 varieties of these reservoirs can be distinguished:

1. Pacific - 25 seas, including Bering, Yellow, Japanese, Philippine, Tasmanovo, Fiji, Okhotsk, East China, etc.
2. Atlantic - 16 seas, including the Baltic, Azov, Caribbean, North, Mediterranean, Aegean, Black, etc.
3. Indian Ocean - 11 seas, including the Arabian, Red, Timor and others.
4. Arctic - 11 seas, including the Barents, East Siberian, Pechora, Laptev, Kara, Chukchi, etc.
5. South Oceanic - seas of Antarctica: Amundsen, Bellingshausen, Commonwealth, Cosmonauts, etc.

What are the seas: names according to isolation from the ocean

1. Inter-island - located in a dense ring of islands that interfere with active water exchange with the ocean: Sulawesi, Yavanskoye, etc.
2. Intercontinental (Mediterranean) - surrounded by land so that they communicate with the ocean by only a few straits: Red, Mediterranean, Caribbean, etc.
3. The marginal ones - freely communicating with the vastness of the ocean, currents in them are also formed due to its winds. The ocean also affects the nature of their bottom sediments, microclimate, flora and fauna: Japan, South China, Beringovo, Okhotsk, etc.
4. Internal - completely closed from contact with the ocean land. Internally, they are divided into inland (Russian Black, Yellow) and inter-continental (Red, Mediterranean), as well as isolated - not in contact with other similar bodies of water (Aral or Dead), semi-closed (for example, Azov, Baltic).

Distribution of seas by salinity

1. Lightly salted seas - the percentage of salt is lower than in ocean waters. For example, the Black Sea belongs exactly here.
2. Highly saline seas - the percentage of salinity of their waters is higher than that of the ocean. The Red Sea is a good example.

There are no seas with fresh water, as can be seen from the classification.

Other classifications of the seas

What else is the sea? According to the temperature of the waters, sea water bodies are divided into tropical, temperate climates and polar - northern and southern.

According to the severity of the indentedness of the coastline, the sea can be divided into strongly indented and weakly indented. But, for example, the Sargasso Sea does not have such a line at all.

Asking ourselves: "What is the sea like?", Each of us will make his own classification: calm, formidable, affectionate, raging, enchanting, warm, icy, distant or close. Scientific categories are more suitable for professional research of these reservoirs.

1. What is the difference between seas and oceans?

The sea is part of the World Ocean. The sea is a large body of water, which is bounded on one or several sides by land and separated from the ocean by elevations of the underwater relief or islands. The ocean is the entire body of water on Earth. The ocean surrounds islands and continents. From the above definitions, it can be concluded that the sea is only a part of the World Ocean, which is separated from it by elevations of the underwater relief or by land.

2. List the main features of the seas of Russia.

The seas of Russia have a number of unique features:

The seas of Russia are located in cold climatic zones and in winter period are covered with ice, during this period the navigation of ships is extremely difficult.

The Barents, Bering and Okhotsk Seas are among the most productive seas in the world, and the productivity of the West Kamchatka shelf is the highest in the world and is about 20 t / km2.

In the Far Eastern seas of Russia, stocks of commercial species are concentrated, having world significance: Alaska pollock, Pacific salmon, Kamchatka crab.

In the Arctic and Pacific waters, significantly larger (in comparison with the North Atlantic) stocks of cod have been preserved.

The Russian seas have the world's highest variety of sturgeon and salmon fish.

The most important migration routes of marine mammals and birds of the northern hemisphere pass along the coast of the Russian seas.

Unique ecosystems have been discovered in the Russian seas: the relict ecosystem of Lake Mogilnoye, relict ecosystems of kelps in the Arctic (Chaunskaya Bay), shallow hydrothermal communities in the bays of the Kuril Islands.

3. What are the resources of the seas of Russia? Why do seas need protection?

The seas of Russia have a variety of resources that are of great economic importance. First of all, these are cheap transport routes connecting our country both with other states and with its individual regions (the Northern Sea Route passes through the seas of the Arctic Ocean). The biological resources of the seas, primarily their fish resources, are of significant value. Almost 900 fish species live in the seas washing Russia. Of more than 250 species of commercial. The importance of the mineral resources of the seas is growing more and more. The energy of the tides can be used to generate electricity. So far, Russia has only one small tidal power plant - the Kislogubskaya TPP on the Barents Sea. The seas are also places of rest. Certainly, most of of the seas of our country has too harsh natural conditions for people to rest there. But the southern seas - the Azov, Black, Caspian and Japanese seas attract a large number of tourists. However, drawing people's attention to the seas carries the threat of depletion of the listed resources, and the seas are also very often used as a place for the discharge of liquid waste, therefore, a system for protecting the seas is very important.

4. Choose the correct answer. The largest and deepest sea off the coast of Russia: a) Black; b) Beringovo; c) Barents; d) Okhotsk.

6.-7. Mark on outline map the seas washing the shores of Russia, the bays of Finsky, Anadyrsky, Shelikhov, Penzhinskaya Bay, Ob Bay, the Kara Vorota, Long, Vilkitsky, Tatarsky straits. On the outline map, use the arrows to indicate the Northern Sea Route. Sign the seas, straits through which it passes; apply large ports.

8. Marine painters in their works depict the sea. What works do you know? Who are they created by? Why are you interested in the image of the sea? How do you feel about a painting of the sea?

The sea is an inexhaustible source of inspiration for many creative people... Ivan Konstantinovich Aivazovsky, a genius whose talent is recognized throughout the world. He was compared to a poet who composed poems with a brush. Ivan Konstantinovich's paintings are striking in their monumentality, play of colors and realism. After watching his canvases, you want to drop everything and fly to the sea. Russian artist Artem Chekhov, a master of digital painting and catchy images, creates his masterpieces in Photoshop, using traditional techniques and materials. Despite the fact that the basis of the work is pixels, and not oil strokes, the paintings are mesmerizing, and it seems that in a moment they will come to life. The grandson of the writer A.N. Radishchev and also a famous Russian marine painter. Alexey Petrovich was not only a professor of painting and an influential person, but also a benefactor for the benefit of the widows and orphans of artists. His paintings are academic, but at the same time imbued with love for nature and its movements. The painting by Ivan Aivazovsky "Rainbow" evokes the following feelings: the clouds in the sky have dissolved in a transparent wet veil. A stream of sunlight made its way through this chaos, fell like a rainbow on the water, imparting a multicolor color to the color of the picture. The whole picture is painted in the finest shades of blue, green, pink and purple paints. The same tones, slightly enhanced in color, convey the rainbow itself. It shimmers with a subtle mirage. From this, the rainbow acquired that transparency, softness and purity of color, which we always admire and enchant in nature. The painting "Rainbow" was a new, higher step in the work of Aivazovsky. Regarding one of these paintings by Aivazovsky F.M. Dostoevsky wrote: "The storm ... of Mr. Aivazovsky ... is amazingly good, like all his storms, and here he is a master - without rivals ... There is rapture in his storm, there is that eternal beauty that amazes the viewer in a living, real storm ..."