The seas of Russia are the Caspian Sea. The Caspian Sea is one of the most amazing closed bodies of water on Earth. Why is the Caspian Sea cold?

The Caspian Sea is located at the junction of two parts of the Eurasian continent - Europe and Asia. The Caspian Sea is shaped like Latin letter S, the length of the Caspian Sea from north to south is approximately 1200 kilometers (36°34" - 47°13" N), from west to east - from 195 to 435 kilometers, on average 310-320 kilometers (46° - 56° E).

The Caspian Sea is conventionally divided according to physical and geographical conditions into 3 parts - the Northern Caspian, the Middle Caspian and the Southern Caspian. The conditional border between the Northern and Middle Caspian Seas passes along the Chechen line (island)- Tyub-Karagansky Cape, between the Middle and Southern Caspian Seas - along the Zhiloi line (island)- Gan-Gulu (Cape). The area of ​​the Northern, Middle and Southern Caspian Sea is 25, 36, 39 percent, respectively.

According to one hypothesis, the Caspian Sea received its name in honor of the ancient tribes of horse breeders - the Caspians, who lived BC in the south. west coast Caspian Sea. Throughout the history of its existence, the Caspian Sea had about 70 names among different tribes and peoples: the Hyrcanian Sea; The Khvalyn Sea or the Khvalis Sea is an ancient Russian name, derived from the name of the inhabitants of Khorezm who traded in the Caspian Sea - Khvalis; Khazar Sea - name in Arabic (Bahr al-Khazar), Persian (Darya-e Khazar), Turkish and Azerbaijani (Khazar denizi) languages; Abeskun Sea; Sarayskoye Sea; Derbent Sea; Xihai and other names. In Iran, the Caspian Sea is still called the Khazar or Mazandaran Sea. (after the name of the people inhabiting the coastal province of Iran of the same name).

Coastline The Caspian Sea is estimated at approximately 6500 - 6700 kilometers, with islands - up to 7000 kilometers. The shores of the Caspian Sea in most of its territory are low-lying and smooth. In the northern part, the coastline is indented by water streams and islands of the Volga and Ural deltas, the banks are low and swampy, and the water surface in many places is covered with thickets. On east coast Limestone coasts predominate, adjacent to semi-deserts and deserts. The most winding shores are on the western coast in the area of ​​the Absheron Peninsula and on the eastern coast in the area of ​​the Kazakh Gulf and Kara-Bogaz-Gol.

Large peninsulas of the Caspian Sea: Agrakhan Peninsula, Absheron Peninsula, Buzachi, Mangyshlak, Miankale, Tub-Karagan.

There are about 50 large and medium-sized islands in the Caspian Sea with a total area of ​​approximately 350 square kilometers. The largest islands: Ashur-Ada, Garasu, Gum, Dash, Zira (island), Zyanbil, Kur Dashi, Khara-Zira, Sengi-Mugan, Chechen (island), Chygyl.

Large bays of the Caspian Sea: Agrakhansky Bay, Komsomolets (bay) (formerly Dead Kultuk, formerly Tsesarevich Bay), Kaydak, Mangyshlak, Kazakh (bay), Turkmenbashi (bay) (formerly Krasnovodsk), Turkmen (bay), Gizilagach, Astrakhan (bay), Gyzlar, Girkan (formerly Astarabad) and Anzeli (formerly Pahlavi).

On the eastern coast is the salt lake Kara Bogaz Gol, which until 1980 was a bay-lagoon of the Caspian Sea, connected to it by a narrow strait. In 1980, a dam was built separating Kara-Bogaz-Gol from the Caspian Sea, and in 1984 a culvert was built, after which the level of Kara-Bogaz-Gol dropped by several meters. In 1992, the strait was restored, through which water flows from the Caspian Sea to Kara-Bogaz-Gol and evaporates there. Every year, 8 - 10 cubic kilometers of water flow from the Caspian Sea to Kara-Bogaz-Gol (according to other sources - 25 thousand kilometers) and about 150 thousand tons of salt.

130 rivers flow into the Caspian Sea, of which 9 rivers have a delta-shaped mouth. Large rivers flowing into the Caspian Sea - Volga, Terek (Russia), Ural, Emba (Kazakhstan), Kura (Azerbaijan), Samur (Russian border with Azerbaijan), Atrek (Turkmenistan) and others. The largest river flowing into the Caspian Sea is the Volga, its average annual flow is 215-224 cubic kilometers. The Volga, Ural, Terek and Emba provide up to 88 - 90% of the annual runoff of the Caspian Sea.

The area of ​​the Caspian Sea basin is approximately 3.1 - 3.5 million square kilometers, which is approximately 10 percent of the world's closed water basin area. The length of the Caspian Sea basin from north to south is about 2500 kilometers, from west to east - about 1000 kilometers. The Caspian Sea basin covers 9 states - Azerbaijan, Armenia, Georgia, Iran, Kazakhstan, Russia, Uzbekistan, Turkey and Turkmenistan.

The Caspian Sea washes the shores of five coastal states:

• Russia (Dagestan, Kalmykia and Astrakhan region)- in the trap and north-west, the length of the coastline is 695 kilometers
• Kazakhstan - in the north, northeast and east, the length of the coastline is 2320 kilometers
• Turkmenistan - in the southeast, the length of the coastline is 1200 kilometers
• Iran - in the south, coastline length - 724 kilometers
• Azerbaijan - in the southwest, the length of the coastline is 955 kilometers

The largest city and port on the Caspian Sea is Baku, the capital of Azerbaijan, which is located in the southern part of the Absheron Peninsula and has a population of 2,070 thousand people. (2003) . Other major Azerbaijani Caspian cities are Sumgait, which is located in the northern part of the Absheron Peninsula, and Lankaran, which is located near the southern border of Azerbaijan. To the South-East of the Absheron Peninsula, the oil workers’ village of Neftyanye Kamni is located, the buildings of which stand on artificial islands, overpasses and technological sites.

Large Russian cities- the capital of Dagestan Makhachkala and the most Southern City Russia Derbent - located on the western coast of the Caspian Sea. Astrakhan is also considered a port city of the Caspian Sea, which, however, is not located on the shores of the Caspian Sea, but in the Volga delta, 60 kilometers from the northern coast of the Caspian Sea.

On east coast On the Caspian Sea there is a Kazakh city - the port of Aktau, in the north in the Ural delta, 20 km from the sea, the city of Atyrau is located, south of Kara-Bogaz-Gol on the northern shore of the Krasnovodsk Bay - the Turkmen city of Turkmenbashi, former Krasnovodsk. Several Caspian cities are located in the southern (Iranian) coast, the largest of them is Anzeli.

The area and volume of water of the Caspian Sea varies significantly depending on fluctuations in water levels. At a water level of −26.75 m, the area was approximately 392,600 square kilometers, the volume of water was 78,648 cubic kilometers, which is approximately 44 percent of the world's lake water reserves. The maximum depth of the Caspian Sea is in the South Caspian depression, 1025 meters from its surface level. In terms of maximum depth, the Caspian Sea is second only to Lake Baikal (1620 m.) and Tanganyika (1435 m.). The average depth of the Caspian Sea, calculated from the bathygraphic curve, is 208 meters. At the same time, the northern part of the Caspian Sea is shallow, its maximum depth does not exceed 25 meters, and the average depth is 4 meters.

The water level in the Caspian Sea is subject to significant fluctuations. According to modern science, over the past 3 thousand years the amplitude of changes in the water level of the Caspian Sea has been 15 meters. Instrumental measurements of the level of the Caspian Sea and systematic observations of its fluctuations have been carried out since 1837, during which time the highest water level was recorded in 1882 (-25.2 m.), lowest - in 1977 (-29.0 m.), since 1978 the water level has risen and in 1995 reached −26.7 m; since 1996, a downward trend has emerged again. Scientists associate the reasons for changes in the water level of the Caspian Sea with climatic, geological and anthropogenic factors.

Water temperature is subject to significant latitudinal changes, most clearly expressed in winter, when the temperature varies from 0 - 0.5 °C at the ice edge in the north of the sea to 10 - 11 °C in the south, that is, the difference in water temperature is about 10 °C. For shallow water areas with depths less than 25 m, the annual amplitude can reach 25 - 26 °C. On average, the water temperature off the west coast is 1 - 2 °C higher than that on the east, and in the open sea the water temperature is 2 - 4 °C higher than on the coasts. Based on the nature of the horizontal structure of the temperature field in the annual cycle of variability, three time periods can be distinguished in the upper 2-meter layer. From October to March, the water temperature increases in the southern and eastern regions, which is especially clearly visible in the Middle Caspian. Two stable quasi-latitudinal zones can be distinguished, where temperature gradients are increased. This is, firstly, the border between the Northern and Middle Caspian, and, secondly, between the Middle and Southern. At the ice edge, in the northern frontal zone, the temperature in February-March increases from 0 to 5 °C, in the southern frontal zone, in the area of ​​the Absheron threshold, from 7 to 10 °C. During this period, the least cooled waters are in the center of the South Caspian Sea, which form a quasi-stationary core. In April-May, the area of ​​minimum temperatures moves to the Middle Caspian Sea, which is associated with faster heating of waters in the shallow northern part of the sea. True, at the beginning of the season in the northern part of the sea a large amount of heat is spent on melting ice, but already in May the temperature here rises to 16 - 17 °C. In the middle part the temperature at this time is 13 - 15 °C, and in the south it increases to 17 - 18 °C. Spring warming of water evens out horizontal gradients, and the temperature difference between coastal areas and the open sea does not exceed 0.5 °C. Warming of the surface layer, which begins in March, disrupts the uniformity of temperature distribution with depth. In June-September, horizontal uniformity in the temperature distribution in the surface layer is observed. In August, which is the month of greatest warming, the water temperature throughout the sea is 24 - 26 °C, and in the southern regions it rises to 28 °C. In August, the water temperature in shallow bays, for example, in Krasnovodsk, can reach 32 °C. The main feature of the water temperature field at this time is upwelling. It is observed annually along the entire eastern coast of the Middle Caspian and partially penetrates even into the Southern Caspian. The rise of cold deep waters occurs with varying intensity as a result of the influence of prevailing summer season northwest winds. The wind in this direction causes the outflow of warm surface waters from the coast and the rise of colder waters from the intermediate layers. Upwelling begins in June, but it reaches its greatest intensity in July-August. As a result, a decrease in temperature is observed on the water surface (7 - 15 °C). Horizontal temperature gradients reach 2.3 °C on the surface and 4.2 °C at a depth of 20 m. The source of upwelling gradually shifts from 41 - 42° N. in June to 43 - 45° N. in September. Summer upwelling is of great importance for the Caspian Sea, radically changing the dynamic processes in the deep-water area. In open areas of the sea, at the end of May - beginning of June, the formation of a temperature jump layer begins, which is most clearly expressed in August. Most often it is located between horizons of 20 and 30 m in the middle part of the sea and 30 and 40 m in the southern part. Vertical temperature gradients in the shock layer are very significant and can reach several degrees per meter. In the middle part of the sea, due to the surge off the eastern coast, the shock layer rises close to the surface. Since in the Caspian Sea there is no stable baroclinic layer with a large reserve of potential energy similar to the main thermocline of the World Ocean, then with the cessation of the prevailing winds causing upwelling and with the beginning of autumn-winter convection in October-November, a rapid restructuring of temperature fields to the winter regime occurs. In the open sea, the water temperature in the surface layer drops in the middle part to 12 - 13 °C, in the southern part to 16 - 17 °C. In the vertical structure, the shock layer is eroded due to convective mixing and disappears by the end of November.

The salt composition of the waters of the closed Caspian Sea differs from the oceanic one. There are significant differences in the ratios of concentrations of salt-forming ions, especially for waters in areas directly influenced by continental runoff. The process of metamorphization of sea waters under the influence of continental runoff leads to a decrease in the relative content of chlorides in the total amount of salts of sea waters, an increase in the relative amount of carbonates, sulfates, calcium, which are the main components in chemical composition river waters. The most conservative ions are potassium, sodium, chlorine and magnesium. The least conservative are calcium and bicarbonate ions. In the Caspian Sea, the content of calcium and magnesium cations is almost two times higher than in the Sea of ​​Azov, and the sulfate anion is three times higher. Water salinity changes especially sharply in the northern part of the sea: from 0.1 units. psu in the mouth areas of the Volga and Ural up to 10 - 11 units. psu on the border with the Middle Caspian. Mineralization in shallow salty bays-kultuks can reach 60 - 100 g/kg. In the Northern Caspian, during the entire ice-free period from April to November, a salinity front of a quasi-latitudinal location is observed. The greatest desalination, associated with the spread of river flow across the sea, is observed in June. The formation of the salinity field in the Northern Caspian Sea is greatly influenced by the wind field. In the middle and southern parts of the sea, salinity fluctuations are small. Basically it is 11.2 - 12.8 units. psu, increasing in the southern and eastern directions. Salinity increases slightly with depth (by 0.1 - 0.2 psu units). In the deep-sea part of the Caspian Sea, in the vertical profile of salinity, characteristic deflections of isohalines and local extrema are observed in the area of ​​the eastern continental slope, which indicate the processes of bottom sliding of waters salinizing in the eastern shallow waters of the South Caspian. The salinity value also strongly depends on sea level and (which is related) on the volume of continental runoff.

The relief of the northern part of the Caspian Sea is a shallow undulating plain with banks and accumulative islands, the average depth of the Northern Caspian Sea is about 4 - 8 meters, the maximum does not exceed 25 meters. The Mangyshlak threshold separates the Northern Caspian from the Middle Caspian. The Middle Caspian is quite deep, the water depth in the Derbent depression reaches 788 meters. The Absheron threshold separates the Middle and Southern Caspian Seas. The Southern Caspian is considered deep-sea; the water depth in the South Caspian depression reaches 1025 meters from the surface of the Caspian Sea. Shell sands are widespread on the Caspian shelf, deep-sea areas are covered with silty sediments, and in some areas there is an outcrop of bedrock.

The climate of the Caspian Sea is continental in the northern part, temperate in the middle and subtropical in the southern part. In winter, the average monthly temperature of the Caspian Sea varies from −8 −10 in the northern part to +8 - +10 in the southern part, in summer - from +24 - +25 in the northern part to +26 - +27 in the southern part. The maximum temperature recorded on the east coast was 44 degrees.

The average annual precipitation is 200 millimeters per year, ranging from 90-100 millimeters in the arid eastern part to 1,700 millimeters along the southwestern subtropical coast. Evaporation of water from the surface of the Caspian Sea is about 1000 millimeters per year, the most intense evaporation in the area of ​​the Absheron Peninsula and in the eastern part of the South Caspian Sea is up to 1400 millimeters per year.

Winds often blow on the territory of the Caspian Sea, their average annual speed is 3-7 meters per second, the wind rose is dominated by north winds. In the autumn and winter months, winds become stronger, with wind speeds often reaching 35-40 meters per second. The most windy areas are the Absheron Peninsula and the environs of Makhachkala - Derbent, where the highest wave was recorded - 11 meters.

Water circulation in the Caspian Sea is related to runoff and winds. Since most of the drainage occurs in the Northern Caspian Sea, northern currents predominate. An intense northern current carries water from the Northern Caspian along the western coast to the Absheron Peninsula, where the current divides into two branches, one of which moves further along the western coast, the other goes to the Eastern Caspian.

The fauna of the Caspian Sea is represented by 1810 species, of which 415 are vertebrates. 101 species of fish are registered in the Caspian world, where most of the world's sturgeon reserves are concentrated, as well as freshwater fish such as roach, carp, and pike perch. The Caspian Sea is the habitat of fish such as carp, mullet, sprat, kutum, bream, salmon, perch, and pike. The Caspian Sea is also home to a marine mammal - the Caspian seal. Since March 31, 2008, 363 dead seals have been found on the coast of the Caspian Sea in Kazakhstan.

The flora of the Caspian Sea and its coast is represented by 728 species. Among the plants in the Caspian Sea, the predominant algae are blue-green, diatoms, red, brown, characeae and others, and among the flowering plants - zoster and ruppia. In origin, the flora is predominantly of Neogene age, but some plants were brought into the Caspian Sea by humans deliberately or on the bottoms of ships.

, Kura

42° N. w. 51° east d. HGIOL

Caspian Sea- the largest closed body of water on Earth, which can be classified as the largest closed lake, or as a full-fledged sea, due to its size, and also because its bed is composed of oceanic-type crust. Located at the junction of Europe and Asia. The water in the Caspian Sea is brackish, from 0.05 ‰ near the mouth of the Volga to 11-13 ‰ in the southeast. The water level is subject to fluctuations, according to 2009 data it was 27.16 m below sea level. The area of ​​the Caspian Sea is currently approximately 371,000 km², the maximum depth is 1025 m.

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Subtitles

Etymology

Geographical position

The Caspian Sea is located at the junction of Europe and Asia. The length of the sea from north to south is approximately 1200 kilometers (36°34"-47°13" N), from west to east - from 195 to 435 kilometers, on average 310-320 kilometers (46°-56° in .d.).

According to physical and geographical conditions, the Caspian Sea is conventionally divided into three parts - the Northern Caspian (25% of the sea area), the Middle Caspian (36%) and the Southern Caspian (39%). The conditional border between the Northern and Middle Caspian runs along the line Chechen Island - Cape Tyub-Karagan, between the Middle and Southern Caspian - along the line Chilov Island - Cape Gan-Gulu.

Coast

The territory adjacent to the Caspian Sea is called the Caspian region.

Peninsulas

• Absheron Peninsula, located on the western coast of the Caspian Sea on the territory of Azerbaijan, at the northeastern end of the Greater Caucasus, on its territory the cities of Baku and Sumgait are located
• Mangyshlak, located on the eastern coast of the Caspian Sea, on the territory of Kazakhstan, on its territory is the city of Aktau

Islands

There are about 50 large and medium-sized islands in the Caspian Sea with a total area of ​​approximately 350 square kilometers.

Largest islands:

Bays

Large bays:

Kara-Bogaz-Gol

On the eastern coast is the salt lake Kara-Bogaz-Gol, which until 1980 was a bay-lagoon of the Caspian Sea, connected to it by a narrow strait. In 1980, a dam was built separating Kara-Bogaz-Gol from the Caspian Sea, and in 1984 a culvert was built, after which the level of Kara-Bogaz-Gol dropped by several meters. In 1992, the strait was restored, through which water flows from the Caspian Sea to Kara-Bogaz-Gol and evaporates there. Every year, 8-10 cubic kilometers of water (according to other sources - 25 cubic kilometers) and about 15 million tons of salt flow into Kara-Bogaz-Gol from the Caspian Sea.

Rivers flowing into the Caspian Sea

130 rivers flow into the Caspian Sea, of which 9 rivers have a delta-shaped mouth. Large rivers flowing into the Caspian Sea are Volga, Terek, Sulak, Samur (Russia), Ural, Emba (Kazakhstan), Kura (Azerbaijan), Atrek (Turkmenistan), Sefidrud (Iran). The largest river flowing into the Caspian Sea is the Volga, its average annual flow is 215-224 cubic kilometers. The Volga, Ural, Terek, Sulak and Emba provide up to 88-90% of the annual flow into the Caspian Sea.

Basin of the Caspian Sea

Coastal states

According to the Intergovernmental Economic Conference of the Caspian States:

The Caspian Sea washes the shores of five coastal states:

Cities on the Caspian Sea coast

On the Russian coast are the cities of Lagan, Makhachkala, Kaspiysk, Izberbash, Dagestanskie Ogni and the southernmost city of Russia, Derbent. Astrakhan is also considered a port city of the Caspian Sea, which, however, is not located on the shores of the Caspian Sea, but in the Volga delta, 60 kilometers from the northern coast of the Caspian Sea.

Physiography

Area, depth, volume of water

The area and volume of water in the Caspian Sea varies significantly depending on fluctuations in water levels. At a water level of −26.75 m, the area is approximately 371,000 square kilometers, the volume of water is 78,648 cubic kilometers, which is approximately 44% of the world's lake water reserves. The maximum depth of the Caspian Sea is in the South Caspian depression, 1025 meters from its surface level. In terms of maximum depth, the Caspian Sea is second only to Baikal (1620 m) and Tanganyika (1435 m). The average depth of the Caspian Sea, calculated from the bathygraphic curve, is 208 meters. At the same time, the northern part of the Caspian Sea is shallow, its maximum depth does not exceed 25 meters, and the average depth is 4 meters.

Water level fluctuations

Vegetable world

The flora of the Caspian Sea and its coast is represented by 728 species. The predominant plants in the Caspian Sea are algae - blue-green, diatoms, red, brown, characeae and others, and flowering plants - zoster and ruppia. In origin, the flora is predominantly of Neogene age, however, some plants were brought into the Caspian Sea by humans deliberately, or on the bottoms of ships.

Story

Origin

The Caspian Sea is of oceanic origin - its bed is composed of oceanic-type crust. 13 million l. n. the resulting Alps separated the Sarmatian Sea from the Mediterranean. 3.4 - 1.8 million l. n. (Pliocene) there was the Akchagyl Sea, the sediments of which were studied by N. I. Andrusov. It was originally formed on the site of the dried-up Pontic Sea, from which Lake Balakhanskoe (in the southern Caspian Sea) remained. The Akchagyl transgression gave way to the Domashkin regression (a drop of 20 - 40 m from the level of the Akchagyl basin), accompanied by a strong desalination of sea waters, which is due to the cessation of the flow of sea (ocean) waters from the outside. After a short Domashkin regression at the beginning of the Quaternary period (Eopleistocene), the Caspian Sea is almost restored in the form of the Absheron Sea, which covers the Caspian Sea and floods the territories of Turkmenistan and the Lower Volga region. At the beginning of the Absheron transgression, the basin turns into a brackish water body. The Absheron Sea exists from 1.7 to 1 million years ago. The beginning of the Pleistocene in the Caspian Sea was marked by a long and deep Turkic regression (-150 m to −200 m), corresponding to the Matuyama-Brunhes magnetic reversal (0.8 million years ago). The water mass of the Turkian basin with an area of ​​208 thousand km² was concentrated in the South Caspian and part of the Middle Caspian basins, between which there was a shallow strait in the area of ​​the Absheron threshold. In the early Neopleistocene, after the Turkic regression, there existed an isolated Early Baku and a Late Baku (level up to 20 m) drainage basins (about 400 thousand years ago). The Vened (Mishovdag) regression divided the Baku and Urundzhik (middle Neopleistocene, up to −15 m) transgressions at the end of the early - beginning of the late Pleistocene (basin area - 336 thousand km²). Between the marine Urundzhik and Khazar deposits, a large deep Cheleken regression (up to −20 m) was noted, corresponding to the optimum of the Likhvin interglacial (350-300 thousand years ago). In the Middle Neopleistocene there were basins: early Khazar (200 thousand years ago), early Khazar middle (level up to 35-40 m) and early Khazar late. In the late Neopleistocene, there was an isolated late Khazar basin (level up to −10 m, 100 thousand years ago), after which a small Chernoyarsk regression occurred in the second half - the end of the Middle Pleistocene (thermoluminescent dates 122-184 thousand years ago), in in turn, replaced by the Hyrcanian (Gyurgyan) basin.

The deep long-term Atelian regression of the mid-Late Pleistocene at the initial stage had a level of −20 - −25 m, at the maximum stage −100 - −120 m, at the third stage - −45 - −50 m. At the maximum, the basin area is reduced to 228 thousand km² . After Atel regression (−120 - −140 m), approx. 17 thousand l. n. The early Khvalynian transgression began - up to + 50 m (the Manych-Kerch Strait was functioning), which was interrupted by the Eltonian regression. The Early Khvalyn II basin (level up to 50 m) was replaced at the beginning of the Holocene by a short-term Enotaev regression (from −45 to −110 m), coinciding in time with the end of the Preboreal and the beginning of the Boreal. The Enotayevskaya regression gave way to the Late Khvalynskaya transgression (0 m). The Late Khvalynian transgression was replaced in the Holocene (ca. 9-7 thousand years ago or 7.2-6.4 thousand years ago) by the Mangyshlak regression (from −50 to −90 m). The Mangyshlak regression gave way during the first phase of interglacial cooling and humidification (Atlantic period) to the New Caspian transgression. The New Caspian basin was brackish-water (11-13 ‰), warm-water and isolated (level up to −19 m). At least three cycles of transgressive-regressive phases have been recorded in the development of the Novo-Caspian basin. The Dagestan (Gousan) transgression previously belonged to the initial stage of the New Caspian era, but the absence of a leading New Caspian form in its sediments Cerastoderma glaucum (Cardium edule) gives grounds for identifying it as an independent transgression of the Caspian Sea. The Izberbash regression, separating the Dagestan and the Neo-Caspian transgressions of the Caspian Sea itself, occurred between 4.3 and 3.9 thousand years ago. Judging by the structure of the Turali section (Dagestan) and radiocarbon analysis data, transgressions were noted twice - about 1900 and 1700 years ago.

Anthropological and cultural history of the Caspian Sea

Shipping

Shipping is developed in the Caspian Sea. On the Caspian Sea there are ferry crossings, in particular, Baku - Turkmenbashi, Baku - Aktau, Makhachkala - Aktau. The Caspian Sea has a shipping connection with the Sea of ​​Azov through the Volga, Don and Volga-Don Canal rivers.

Fishing and seafood production

Fishing (sturgeon, bream, carp, pike perch, sprat), caviar production, as well as seal fishing. More than 90 percent of the world's sturgeon catch occurs in the Caspian Sea. In addition to industrial mining, illegal mining of sturgeon and their caviar flourishes in the Caspian Sea.

Recreational resources

Natural environment of the Caspian coast with sandy beaches, mineral waters and healing mud in the coastal zone creates good conditions for relaxation and treatment. At the same time, according to the degree of development of resorts and the tourism industry Caspian coast noticeably loses to the Black Sea coast of the Caucasus. At the same time, in recent years, the tourism industry has been actively developing on the coasts of Azerbaijan, Iran, Turkmenistan and Russian Dagestan. In Azerbaijan, the resort area in the Baku region is actively developing. At the moment, a world-class resort has been created in Amburan, another modern tourist complex is being built in the area of ​​​​the village of Nardaran, and holidays in the sanatoriums of the villages of Bilgah and Zagulba are very popular. A resort area is also being developed in Nabran, in northern Azerbaijan. However high prices, in general, the low level of service and lack of advertising lead to the fact that there are almost no foreign tourists. Development tourism industry in Turkmenistan, the long-term policy of isolation is hampering, in Iran - Sharia laws, due to which mass recreation foreign tourists on the Caspian coast of Iran is impossible.

Ecological problems

Environmental problems of the Caspian Sea are associated with water pollution as a result of oil production and transportation on the continental shelf, the flow of pollutants from the Volga and other rivers flowing into the Caspian Sea, the life activity of coastal cities, as well as the flooding of individual objects due to rising levels of the Caspian Sea. Predatory production of sturgeon and their caviar, rampant poaching lead to a decrease in the number of sturgeon and to forced restrictions on their production and export.

Legal status

After the collapse of the USSR, the division of the Caspian Sea has long been and still remains the subject of unresolved disagreements related to the division of Caspian shelf resources - oil and gas, as well as biological resources. For a long time, negotiations were ongoing between the Caspian states on the status of the Caspian Sea - Azerbaijan, Kazakhstan and Turkmenistan insisted on dividing the Caspian along the median line, Iran insisted on dividing the Caspian by one-fifth between all Caspian states.

In relation to the Caspian Sea, the key is the physical-geographical circumstance that it is a closed inland body of water that does not have a natural connection with the World Ocean. Accordingly, the norms and concepts of international maritime law, in particular, the provisions of the 1982 UN Convention on the Law of the Sea, should not automatically apply to the Caspian Sea. Based on this, in relation to the Caspian Sea it would be unlawful to apply such concepts as “territorial sea”, “exclusive economic zone”, “continental shelf”, etc.

The current legal regime of the Caspian Sea was established by the Soviet-Iranian treaties of 1921 and 1940. These treaties provide for freedom of navigation throughout the sea, freedom of fishing with the exception of ten-mile national fishing zones and a ban on vessels flying the flag of non-Caspian states sailing in its waters.

Negotiations on the legal status of the Caspian Sea are currently ongoing.

Delineation of sections of the Caspian seabed for subsoil use

The Russian Federation concluded an agreement with Kazakhstan on delimiting the bottom of the northern part of the Caspian Sea in order to exercise sovereign rights to subsoil use (dated July 6, 1998 and the Protocol thereto dated May 13, 2002), an agreement with Azerbaijan on delimiting adjacent areas of the bottom of the northern part of the Caspian Sea (dated September 23, 2002), as well as the trilateral Russian-Azerbaijani-Kazakh agreement on the junction point of the demarcation lines of adjacent sections of the bottom of the Caspian Sea (dated May 14, 2003), which established the geographical coordinates of the dividing lines limiting the sections of the bottom within which the parties exercise their sovereign rights in the field of exploration and production of mineral resources.

The territory of Russia is washed by twelve seas belonging to the basins of three oceans. But one of these seas - the Caspian - is often called a lake, which sometimes confuses people who have little understanding of geography.

Meanwhile, it is really more correct to call the Caspian a lake rather than a sea. Why? Let's figure it out.

A little geography. Where is the Caspian Sea located?

Occupying an area that exceeds 370,000 square kilometers, the Caspian Sea stretches from north to south, dividing its water surface spaces of Europe and Asia. Its coastline belongs to five different countries: Russia, Kazakhstan, Azerbaijan, Turkmenistan and Iran. Geographers conventionally divide its water area into three parts: the Northern (25% of the area), the Middle (36% of the area) and the Southern Caspian (39% of the area), which differ in climate, geological conditions and natural features. The coastline is predominantly flat, indented by river channels, covered with vegetation, and in the northern part, where the Volga flows into the Caspian Sea, it is also swampy.

The Caspian Sea has about 50 large and small islands, about one and a half dozen bays and six large peninsulas. In addition to the Volga, approximately 130 rivers flow into it, and nine rivers form fairly wide and branched deltas. The annual drainage of the Volga is about 120 cubic kilometers. Shared with others large rivers– Terek, Ural, Emba and Sulak – this accounts for up to 90% of the total annual runoff into the Caspian Sea.

Why is the Caspian called a lake?

The main feature of any sea is the presence of straits connecting it to the ocean. The Caspian Sea is a closed or drainless body of water that receives river water, but is not connected to any ocean.


Its water contains a very small amount of salt compared to other seas (about 0.05%) and is considered slightly salty. Due to the absence of at least one strait connecting to the ocean, the Caspian Sea is often called the largest lake in the world, since the lake is a completely enclosed body of water that is fed only by river water.

The waters of the Caspian Sea are not subject to international maritime laws, and its waters are divided between all countries that are adjacent to it, in proportion to the coastline.

Why is the Caspian called a sea?

Despite all of the above, most often in geography, as well as in international and internal documents, the name “Caspian Sea” is used, and not “ Caspian lake" First of all, this is explained by the size of the reservoir, which is much more characteristic of the sea than of the lake. Even, which is much smaller in area than the Caspian Sea, local residents often called the sea. There are no other lakes in the world whose shores belong simultaneously to five different countries.

In addition, you should pay attention to the structure of the bottom, which near the Caspian Sea has a pronounced oceanic type. Once upon a time, the Caspian Sea most likely connected with the Mediterranean, but tectonic processes and drying out separated it from the World Ocean. There are more than fifty islands in the Caspian Sea, and the area of ​​some of them is quite large, even by international standards they are considered large. All this allows us to call the Caspian a sea, and not a lake.

origin of name

Why is this sea (or lake) called the Caspian? The origin of any name is often associated with ancient history terrain. Different peoples who lived on the shores of the Caspian called it differently. More than seventy names of this reservoir have been preserved in history - it was called the Hyrcanian, Derbent, Sarai Sea, etc.


Iranians and Azerbaijanis still call it the Khazar Sea. It began to be called Caspian after the name of the ancient tribe of nomadic horse breeders who lived in the steppes adjacent to its coast - the numerous Caspian tribe. They gave it its name large lake on our planet - the Caspian Sea.

The Caspian Sea is called the most big lake on our planet. It is located between Europe and Asia and is called the sea for its size.

Caspian Sea

The water level is 28m below the level. The water in the Caspian Sea has lower salinity in the north in the delta. The highest salinity is observed in the southern regions.

The Caspian Sea covers an area of ​​371 thousand km2, the greatest depth is 1025 meters (South Caspian Depression). The coastline is estimated to be from 6,500 to 6,700 km, and if we take it together with the islands, then more than 7,000 km.

The seashore is mostly low-lying and smooth. If you look at the northern part, there are many islands and water channels cut by the Volga and the Urals. In these places the shore is swampy and covered with thickets. From the east, a semi-desert and desert area with limestone shores approaches the sea. The region of the Kazakh Gulf, the Absheron Peninsula and the Kara-Bogaz-Gol Bay have winding shores.

Bottom relief

The bottom topography is divided into three main forms. The shelf is in the northern part, the average depth here is from 4 to 9 m, the maximum is 24 m, which gradually increases and reaches 100 m. The continental slope in the middle part drops to 500 m. The northern part is separated from the middle by the Mangyshlak threshold. Here is one of the most deep places Derbent depression (788 m).

2. Heraz, Babol, Sefudrud, Gorgan, Polerud, Chalus, Tejen - https://site/russia/travel/po-dagestanu.html;

4. Atrek - Turkmenistan;

Samur is located on the border between Azerbaijan and Russia, Astarachay is on the border of Azerbaijan and Iran.

The Caspian Sea belongs to five states. From the west and north-west, the length of the coast of 695 km is the territory of Russia. Most of the 2,320 km coastline belongs to Kazakhstan in the east and northeast. Turkmenistan has 1200 km in the south-eastern part, Iran has 724 km in the south and Azerbaijan has 955 km of coastline in the south-west.

In addition to the five states that have access to the sea, the Caspian basin also includes Armenia, Turkey, and Georgia. The sea is connected to the World Ocean by the Volga (Volga-Baltic Route, White Sea-Baltic Canal). There is a connection with the Azov and Black Seas through the Volga-Don Canal, and with the Moscow River (Moscow Canal).

The main ports are Baku in Azerbaijan; Makhachkala in; Aktau in Kazakhstan; Olya in Russia; Noushehr, Bandar-Torkemen and Anzali in Iran.

The largest bays of the Caspian Sea: Agrakhansky, Kizlyarsky, Kaydak, Kazakhsky, Dead Kultuk, Mangyshlaksky, Hasan-kuli, Turkmenbashi, Kazakhsky, Gyzlar, Anzeli, Astrakhan, Gyzlar.

Until 1980, Kara-Bogaz-Gol was a bay-lagoon, which was connected to the sea by a narrow strait. Now it is a salt lake, separated from the sea by a dam. After the construction of the dam, the water began to decrease sharply, so a culvert had to be built. Through it, up to 25 km3 of water enters the lake annually.

Water temperature

The greatest temperature fluctuations are observed in winter. In shallow water it reaches 100 in winter. The difference between summer and winter temperatures reaches 240. On the coast in winter it is always 2 degrees lower than in the open sea. Optimal heating of the water occurs in July-August; in shallow water the temperature reaches 320. But at this time, northwest winds raise cold layers of water (upwelling). This process begins already in June and reaches intensity in August. The temperature at the surface of the water decreases. The temperature difference between the layers disappears by November.

The climate in the northern part of the sea is continental, in the middle part it is temperate, and in the southern part it is subtropical. Temperatures are always higher on the east coast than on the west coast. One day, 44 degrees was recorded on the east coast.

Composition of Caspian waters

About salinity is 0.3%. This is a typical desalinated pool. But the further south you go, the higher the salinity. In the southern part of the sea it already reaches 13%, and in Kara-Bogaz-Gol it is more than 300%.

Storms are frequent in shallow areas. They arise due to changes in atmospheric pressure. Waves can reach 4 meters.

The water balance of the sea depends on river flows and precipitation. Among them, the Volga makes up almost 80% of all other rivers.

In recent years, there has been rapid water pollution with petroleum products and phenols. Their level already exceeds the permissible level.

Minerals

Hydrocarbon production began back in the 19th century. These are the main ones Natural resources. There are also mineral and balneological biological resources here. Nowadays, in addition to gas and oil production, marine salts (astrakhanite, mirabalite, halite), sand, limestone, and clay are mined on the shelf.

Animal and plant life

The fauna of the Caspian Sea includes up to 1800 species. Of these, 415 are vertebrates, 101 are fish species, and there is a world stock of sturgeon. Freshwater fish such as carp, pike perch, and roach also live here. They catch carp, salmon, pike, and bream in the sea. The Caspian Sea is the habitat of one of the mammals - the seal.

Plants include blue-green, brown, and red algae. Zostera and ruppia also grow; they are classified as flowering algae.

The plankton brought into the sea by birds begins to bloom in the spring, the sea is literally covered with greenery, and the rhizosoleums color during flowering most sea ​​areas in yellow-green color. Clusters of rhizosolenia are so thick that they can even calm waves. In some places near the coast, literally meadows of algae have grown.

On the coast you can see both local and migratory birds. In the south, geese and ducks winter, and birds such as pelicans, herons, and flamingos arrange nesting grounds.

The Caspian Sea contains almost 90% of the world's sturgeon stocks. But recently the environment has been deteriorating; you can often meet poachers who hunt sturgeon for their expensive caviar.

States are investing a lot of money to improve the situation. They are purifying wastewater and building fish breeding factories; despite these measures, sturgeon production has to be limited.

Many place names can be misleading to people who are not keen on geography. Could it be that an object designated as a sea on all maps is actually a lake? Let's figure it out.

The history of the appearance of the Caspian Sea?

14,000,000 years ago, the Sarmatian Sea existed on the planet. It included modern, Black, Caspian and Sea of ​​Azov. About 6,000,000 years ago, due to the rise of the Caucasus Mountains and the decrease in water levels in the Mediterranean Sea, it divided, forming four different seas.

The Caspian is inhabited by many representatives of the fauna of Azov, which once again confirms that these reservoirs were once one whole. This is one of the reasons why the Caspian Sea is considered a lake.

The name of the sea comes from the ancient tribes of the Caspian Sea. They inhabited its shores in the first millennia BC and were engaged in horse breeding. But over the many hundreds of years of its existence, this sea has had many names. It was called Derbentsky, Saraisky, Girkansky, Sigai, Kukkuz. Even in our time, for residents of Iran and Azerbaijan, this lake is called Khazar.

Geographical location

Two parts of the world - Europe and Asia - are washed by the waters of the Caspian Sea. The coastline covers the following countries:

• Turkmenistan
• Russia
• Azerbaijan
• Kazakhstan

The length from north to south is about one thousand two hundred kilometers, the width from west to east is about three hundred kilometers. The average depth is about two hundred meters, the greatest depth is about a thousand kilometers. total area The reservoir covers more than 370,000 square kilometers and is divided into three climatic and geographical zones:

1. Northern
2. Average
3. Southern Caspian

The water area includes six large peninsulas and about fifty islands. Their total area is four hundred square kilometers. The largest islands are Dzhambaisky, Ogurchinsky, Chechen, Tyuleniy, Konevsky, Zyudev and the Absheron Islands. About one hundred and thirty rivers flow into the Caspian Sea, including the Volga, Ural, Atrek, Sefirud, Terek, Kura and many others.

Sea or lake?

The official name used in documentation and cartography is the Caspian Sea. But is this true?

In order to have the right to be called a sea, any body of water must be connected to the world's oceans. In the case of the Caspian Sea, this is not reality. The Caspian Sea is separated by almost 500 km of land from the nearest sea, the Black Sea. This is a completely enclosed body of water. The main differences between the seas:

• The seas can be fed by waterways - rivers.
• The external seas are directly connected to the ocean, that is, they have access to it.
• Inland seas are connected to other seas or oceans by straits.

The Caspian received the right to be called a sea primarily because of its impressive size, which is more typical of seas rather than lakes. In area it surpasses even Azov. Also no small role was played by the fact that not a single lake washes the shores of five states at once.

It is worth noting that the structure of the Caspian Sea bottom is of the oceanic type. This happened due to the fact that it was once part of the ancient World Ocean.

Compared to other seas, the percentage of salt saturation in it is very weak and does not exceed 0.05%. The Caspian Sea is fed only by rivers flowing into it, like all lakes on the globe.

Like many seas, the Caspian is famous for its powerful storms. The height of the waves can reach eleven meters. Storms can occur at any time of the year, but they are most dangerous in autumn and winter.

In fact, the Caspian Sea is the most big lake in the world. Its waters are not subject to international maritime laws. The territory of waters is divided between countries on the basis of laws adopted for lakes, and not for seas.

The Caspian Sea has rich mineral resources such as oil and gas. Its waters are inhabited by more than one hundred and twenty species of fish. Among them are the most valuable sturgeons, such as stellate sturgeon, sturgeon, sterlet, beluga, and thorn. 90% of the world's sturgeon catch comes from the Caspian Sea.

Interesting features:

• Scientists around the world have not yet come to a clear conclusion as to why the Caspian Sea is considered a lake. Some experts even suggest considering it a “lake-sea” or an “inland” sea, like the Dead Sea in Israel;
• The most deep point Caspian Sea - more than one kilometer;
• Historically, it is known that the total water level in the reservoir has changed more than once. The exact reasons for this are still not understood;
• It is the only body of water separating Asia and Europe;
• The largest water artery feeding the lake is the Volga River. It is this that carries the bulk of the water;
• Thousands of years ago the Caspian Sea was part of the Black Sea;
• In terms of the number of fish species, the Caspian Sea is inferior to some rivers;
• The Caspian Sea is the main supplier of the most expensive delicacy - black caviar;
• The water in the lake is completely renewed every two hundred and fifty years;
• Japanese territory less area Caspian Sea.

Ecological situation

Intervention into the ecology of the Caspian Sea regularly occurs due to the extraction of oil and natural resources. There are also interventions in the fauna of the reservoir, cases of poaching and illegal fishing of valuable fish species are frequent.

The water level in the Caspian Sea is falling every year. This is due to global warming, due to the influence of which the water temperature on the surface of the reservoir increased by one degree and the sea began to actively evaporate.

It is estimated that water levels have fallen by seven centimeters since 1996. By 2015, the level of the fall was about one and a half meters, and the water continues to fall.

If this continues, in a century the shallowest part of the lake may simply disappear. This will be the part that washes the borders of Russia and Kazakhstan. If global warming intensifies, the process may accelerate and this will happen much earlier.

It is known that long before the onset of global warming, the water level in the Caspian Sea underwent changes. The water kept rising and then falling. Scientists still cannot say exactly why this happened.