It is washed by the Caspian Sea. Interesting facts about the Caspian Sea: depth, relief, coastline, resources. Sulak - water stream of Dagestan

The Caspian Sea is the most big lake On the Earth. It is called the sea because of its size and bed, which is built like an ocean basin. The area is 371,000 square meters, the depth is 1025 m. The list of rivers flowing into the Caspian Sea includes 130 names. The largest of them are: Volga, Terek, Samur, Sulak, Ural and others.

Caspian Sea

It took 10 million years before the Caspian Sea was formed. The reason for its formation is that the Sarmatian Sea, having lost contact with the World Ocean, was divided into two bodies of water, which were called the Black and Caspian Seas. Between the latter and the World Ocean there are thousands of kilometers of waterless route. It is located at the junction of two continents - Asia and Europe. Its length in the north-south direction is 1200 km, west-east - 195-435 km. The Caspian Sea is an internal endorheic basin of Eurasia.

Near the Caspian Sea, the water level is below the level of the World Ocean, and it is also subject to fluctuations. According to scientists, this is due to many factors: anthropogenic, geological, climatic. Currently, the average water level reaches 28 m.

The river network and wastewater are unevenly distributed along the coast. A few rivers flow into part of the sea from the northern side: Volga, Terek, Ural. From the west - Samur, Sulak, Kura. The east coast is characterized by the absence of permanent watercourses. Differences in space in the flow of water that rivers bring to the Caspian Sea are important geographical feature of this reservoir.

Volga

This river is one of the largest in Europe. In Russia it ranks sixth in size. In terms of drainage area, it is second only to Siberian rivers flowing into the Caspian Sea, such as the Ob, Lena, Yenisei, and Irtysh. The source from which the Volga begins is taken to be a spring near the village of Volgoverkhovye, Tver Region, on the Valdai Hills. Now at the source there is a chapel that attracts the attention of tourists who are proud to step over the very beginning of the mighty Volga.

A small fast stream gradually gains strength and becomes a huge river. Its length is 3690 km. The source is 225 m above sea level. Among the rivers flowing into the Caspian Sea, the largest is the Volga. Its path runs through many regions of our country: Tver, Moscow, Nizhny Novgorod, Volgograd and others. The territories through which it flows are Tatarstan, Chuvashia, Kalmykia and Mari El. The Volga is home to millionaire cities - Nizhny Novgorod, Samara, Kazan, Volgograd.

Volga Delta

The main channel of the river is divided into channels. A certain shape of the mouth is formed. It's called delta. Its beginning is the place where the Buzan branch separates from the Volga river bed. The delta is located 46 km north of the city of Astrakhan. It includes channels, branches, and small rivers. There are several main branches, but only Akhtuba is navigable. Among all the rivers of Europe, the Volga has the largest delta, which is a rich fishing region in this basin.

It lies 28 m lower than ocean level. The mouth of the Volga is the location of the southernmost Volga city of Astrakhan, which in the distant past was the capital of the Tatar Khanate. Later, at the beginning of the 18th century (1717), Peter 1 gave the city the status of “capital of the Astrakhan province.” During his reign, the city's main attraction, the Assumption Cathedral, was built. Its Kremlin is made of white stone brought from the capital of the Golden Horde, the city of Saraya. The mouth is divided by branches, the largest of which are: Bolda, Bakhtemir, Buzan. Astrakhan is a southern city located on 11 islands. Today it is a city of shipbuilders, sailors and fishermen.

The Volga currently needs protection. For this purpose, a reserve was established in the place where the river flows into the sea. The delta of the Volga, the largest river flowing into the Caspian Sea, is replete with unique flora and fauna: sturgeon, lotuses, pelicans, flamingos and others. Immediately after the revolution of 1917, a law was passed on their protection by the state as part of the Astrakhan Nature Reserve.

Sulak River

It is located in Dagestan and flows through its territory. It is fed by the waters of melted snow that flow from the mountains, as well as by tributaries: Maly Sulak, Chvakhun-bak, Akh-su. Water also enters Sulak through a canal from the Aksai and Aktash rivers.

The source is formed by the confluence of two rivers that originate in the basins: Didoiskaya and Tushinskaya. The length of the Sulak River is 144 km. Her pool has enough large area- 15,200 square meters. It flows through a canyon with the same name as a river, then through the Akhetlinsky gorge and finally reaches the plane. Rounding the Agrakhan Bay from the south, Sulak flows into the sea.

The river provides Kaspiysk and Makhachkala with drinking water, and is home to hydroelectric power stations, the urban-type settlements of Sulak and Dubki, and the small town of Kizilyurt.

Samur

The river received this name not by chance. The name translated from the Caucasian language (one of them) means “middle”. Indeed, the waterway along the Samur River marks the border between the states of Russia and Azerbaijan.

The sources of the river are glaciers and springs originating in the spurs of the Caucasus Range on the northeastern side, not far from Guton Mountain. The height above sea level is 3200 m. Samur has a length of 213 km. The height at the headwaters and the mouth differs by three kilometers. The drainage basin has an area of almost five thousand square meters.

The places where the river flows are narrow gorges located between the mountains high altitude, composed of clayey shale and sandstone, which is why the water here is cloudy. The Samur basin has 65 rivers. Their length reaches 10 km or more.

Samur: valley and its description

The valley of this river in Dagestan is the most densely populated area. Derbent is located near the mouth - ancient city peace. The banks of the Samur River are home to twenty or more species of relict flora. Endemic, endangered and rare species listed in the Red Book grow here.

In the river delta there is a relict forest, which is the only one in Russia. The liana forest is a fairy tale. Huge trees of the rarest and most common species grow here, intertwined with vines. The river is rich in valuable fish species: mullet, pike perch, pike, catfish and others.

Terek

The river received its name from the Karachay-Balkar peoples who lived along its banks. They called it “Terk Suu”, which means “swift water”. The Ingush and Chechens called it Lomeki - “mountain water”.

The beginning of the river is the territory of Georgia, the Zigla-Khokh glacier is a mountain located on the slope Caucasian ridge. It is located under glaciers all year round. One of them melts when sliding down. A small stream is formed, which is the source of the Terek. It is located at an altitude of 2713 m above sea level. The length of the river flowing into the Caspian Sea is 600 km. When it flows into the Caspian Sea, the Terek is divided into many branches, resulting in the formation of a vast delta, its area is 4000 square meters. In some places it is very swampy.

The riverbed in this place changed several times. The old branches have now been converted into canals. The middle of the last century (1957) was marked by the construction of the Kargaly hydroelectric complex. It is used to supply water to the canals.

How is the Terek replenished?

The river has a mixed supply, but for the upper reaches, water from melting glaciers plays an important role; they fill the river. In this regard, 70% of the flow occurs in spring and summer, that is, at this time the water level in the Terek is highest, and the lowest is in February. The river freezes if the winters are characterized by a harsh climate, but the ice cover is unstable.

The river is not clean and transparent. The turbidity of the water is high: 400-500 g/m3. Every year the Terek and its tributaries pollute the Caspian Sea, pouring into it from 9 to 26 million tons of various suspended matter. This is explained by the rocks that make up the shores, which are clayey.

Estuary Terek

The Sunzha is the largest tributary flowing into the Terek, the lower reaches of which are measured from this river. By this time, the Terek flows for a long time through the flat terrain, leaving the mountains located behind the Elkhotov Gate. The bottom here is made of sand and pebbles, the current slows down, and in some places stops altogether.

The mouth of the Terek River has an unusual appearance: the channel here is raised above the valley, in appearance it resembles a canal, which is fenced with a high embankment. The water level becomes higher than the land level. This phenomenon is due to natural causes. Since the Terek is a turbulent river, it brings sand and stones in large quantities from the Caucasus Range. Considering that the current in the lower reaches is weak, some of them settle here and do not reach the sea. For residents of this area, sediment is both a threat and a blessing. When they are washed away by water, floods of great destructive power occur, this is very bad. But in the absence of floods, the soils become fertile.

Ural River

In ancient times (until the second half of the 18th century) the river was called Yaik. It was renamed in the Russian way by decree of Catherine the Second in 1775. Just at this time, the Peasant War, the leader of which was Pugachev, was suppressed. The name has been preserved to this day in the Bashkir language, and is official in Kazakhstan. The Urals are the third longest in Europe; only the Volga and Danube are larger rivers.

The Urals originate in Russia, on the slope of the Round Hill of the Uraltau ridge. The source is a spring flowing out of the ground at an altitude of 637 m above sea level. At the beginning of its journey, the river flows in a north-south direction, but after meeting a plateau along the way it makes sharp turn and continues to flow in a northwesterly direction. However, beyond Orenburg its direction changes again to the southwest, which is considered the main one. Having overcome a winding path, the Urals flows into the Caspian Sea. The length of the river is 2428 km. The mouth is divided into branches and tends to become shallow.

The Ural is a river along which the natural water boundary between Europe and Asia passes, with the exception of the upper reaches. It is an inland European river, but its headwaters are east of Ural ridge are the territory of Asia.

The importance of the Caspian rivers

The rivers flowing into the Caspian Sea are of great importance. Their waters are used for human and animal consumption, domestic, agricultural and industrial needs. Hydroelectric power stations are built on rivers, the energy of which is in demand by people for various purposes. River basins are full of fish, algae, and shellfish. Even in ancient times, people chose river valleys for future settlements. And now cities and towns are being built on their banks. The rivers are plied by passenger and transport ships, performing important tasks for transporting passengers and cargo.

Caspian Sea- the largest lake on Earth, located at the junction of Europe and Asia, called the sea because of its size. Caspian Sea is a closed lake, and the water in it is salty, from 0.05% near the mouth of the Volga to 11-13% in the southeast.
The water level is subject to fluctuations, currently approximately 28 m below sea level.
Square Caspian Sea currently - approximately 371,000 km2, maximum depth - 1025 m.

Length of coastline Caspian Sea is estimated at approximately 6,500 - 6,700 kilometers, with islands - up to 7,000 kilometers. Shores Caspian Sea Most of its territory is low-lying and smooth. In the northern part coastline cut by water channels 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.

IN Caspian Sea 130 rivers flow in, of which 9 rivers have a delta-shaped mouth. Large rivers flowing into the Caspian Sea are the Volga, Terek (Russia), Ural, Emba (Kazakhstan), Kura (Azerbaijan), Samur (Russian border with Azerbaijan), Atrek (Turkmenistan) and others.

Map of the Caspian Sea

The Caspian Sea washes the shores of five coastal states:

Russia (Dagestan, Kalmykia and Astrakhan region) - in the west and northwest, 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

Water temperature

is subject to significant latitudinal changes, most clearly expressed in winter period, when the temperature changes 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 water temperature difference 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 is west coast 1 - 2 °C higher than in the east, and in the open sea the water temperature is 2 - 4 °C higher than near the coasts.

Climate of the Caspian Sea- continental in the northern part, temperate in the middle part 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 period- 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.

Animal world

The fauna of the Caspian Sea is represented by 1809 species, of which 415 are vertebrates. IN Caspian Sea 101 species of fish are registered, and it contains the majority of the world's sturgeon reserves, as well as freshwater fish such as roach, carp, and pike perch. Caspian Sea- habitat for fish such as carp, mullet, sprat, kutum, bream, salmon, perch, pike. IN Caspian Sea also inhabited by a marine mammal - the Caspian seal.

Vegetable world

Vegetable world Caspian Sea and its coastline is represented by 728 species. From plants to Caspian Sea The predominant algae are blue-green, diatoms, red, brown, characeae and others, and flowering algae include zoster and ruppia. By origin, the flora belongs mainly to the Neogene age, however, some plants were brought in Caspian Sea by a person knowingly or on the bottoms of ships.

Mining of oil and gas

IN Caspian Sea Many oil and gas fields are being developed. Proven oil resources in Caspian Sea are about 10 billion tons, the total resources of oil and gas condensate are estimated at 18 - 20 billion tons.

Oil production in Caspian Sea began in 1820, when the first oil well was drilled on the Absheron shelf. In the second half of the 19th century, oil production began on an industrial scale on the Absheron Peninsula, and then in other territories.

In addition to oil and gas production, on the coast Caspian Sea Salt, limestone, stone, sand, and clay are also mined on the Caspian shelf.

Ecological problems

Ecological problems Caspian Sea 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 Caspian Sea, the life activity of coastal cities, as well as the flooding of individual objects due to rising levels 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.

The Caspian Sea is rightfully the most big lake on the entire planet and this sea-lake is located at the junction of two significant parts of the world: Asia and Europe.

There are still disagreements about the name of the Caspian Sea: is it a sea or a lake. And it is called the sea due to the large size of the reservoir.

Origin of the sea

The Caspian Sea is of oceanic origin. It was formed approximately 10 million years ago as a result of the division of the Sarmatian Sea.

According to one legend, the Caspian reservoir received its modern name in honor of the Caspian tribes living on the southwestern shores. Over all this time, the Caspian Sea has changed its name approximately 70 times.

Currents

The waters of the Caspian Sea can be divided into the following three parts:

southern (39% of the area)
medium (36% of total area)
northern part (25% of the area).

The currents of a reservoir are formed as a result of the following influences: the general influence of the wind regime, differences in density in individual areas and the flow of inflowing rivers.

Along the western coast of the middle part of the Caspian Sea, southern and southeastern currents predominate. Depending on the direction of the winds, the middle and southern parts of the Caspian Sea are characterized by currents in the northern, northwestern, southern and southeastern directions. In the eastern part of the Caspian Sea, eastern currents predominate.

The following currents also play an important role in the circulation of Caspian waters:

seiche;
gradient;
inertial.

What rivers flow into the Caspian Sea

The bulk of river waters enter the Caspian Sea through the Volga River. In addition to the Volga, the following rivers flow into this reservoir:

Samur, flowing on the border of Azerbaijan and Russia;
Astarachay, flowing on the border of Iran and Azerbaijan;
Kura, located in Azerbaijan;
Heraz, Sefudrud, Tejen, Polerud, Chalus, Babol and Gorgan flowing in Iran;
Sulak, Kuma, located on the territory of the Russian Federation;
Emba and Ural, flowing in Kazakhstan;
Atrek, located in Turkmenistan.

Sulak river photo

Where does the Caspian Sea flow into?

The Caspian reservoir has no connection with the ocean, since it is a closed reservoir. The Caspian Sea has dozens of bays. The largest of them can be distinguished: Komsomolets, Gyzlar, Kara-Bogaz-Gol, Mangyshlaksky, Kazakhsky, Krasnovodsky and others. Also in the waters of the Caspian Sea there are about 50 islands of different sizes, with total area more than 350 km2. Some of the islands are united into archipelagos.

Relief

The following forms can be distinguished in the relief of the Caspian Sea bottom: in the south of the reservoir there are deep-sea depressions; a continental slope starting just below the shelf boundary and descending in the southern part of the Caspian to 750m, and in the middle part of the Caspian - up to 600m. shelf, the length of which from the depth to the coastline is 100 m and is covered with shell sands, and in deep water - with silty sediments.

Derbent photo

The coastline of the northern region of the sea is low, quite indented, and flat in some areas. The western shore of the reservoir is rugged and mountainous. In the east, the shores are distinguished by hills. The southern coastline is mostly mountainous. The Caspian Sea is located in a zone of increased seismicity. Also, mud volcanoes often erupt here, most of which are located in the southern part of the reservoir.

Cities

The following states have access to the waters of the Caspian Sea:

Russia. The largest city is Makhachkala, the capital of Dagestan. Also in Dagestan are the cities of Kaspiysk and Izberbash. In addition to the above cities in the Russian Federation on the Caspian Sea, it is necessary to note Derbent, the most Southern City Russia located on the western coast of the Caspian Sea, Olya in the Astrakhan region.
Azerbaijan: The port city of Baku, the capital of Azerbaijan, is located in the southern part of the Absheron Peninsula. One more big city is Sugmait, located in the northern part of the peninsula. Also worth noting are the resorts of Nabran and Lankaran. The latter is located near the southern border of Azerbaijan.
Turkmenistan with the port city of Turkmenbashi.
Iran: Bandar-Torkemen, Anzali, Noushehr.

Makhachkala photo

Flora and fauna

All animal world The waters of the Caspian Sea can be divided conditionally into the following groups:

The first group consists of descendants of ancient organisms: representatives of herrings (bellied, Volga, Kessler and Brazhnikovskaya herring); representatives of the Caspian gobies (golovach, puglovka, Berg, Baer, Knipovich and bubyr); sprat; a large number of crustaceans; some types of shellfish.
The second group includes representatives of fauna that entered the sea from the north during the post-glacial era of desalination of the reservoir: seal; fish species: perch, carp, nelma, whitefish and brown trout; some representatives of crustaceans: sea cockroaches, mysid crustaceans and others.
The third group includes species that entered the Caspian Sea from Mediterranean Sea: the following types of fish: singil, flounder and needle fish; representatives of mollusks; representatives of crustaceans: shrimps, amphipods, crabs.
The fourth group includes representatives of freshwater fish that entered the Caspian Sea from fresh rivers: stellate sturgeon, beluga, sturgeon, Caspian fisherman, red-lipped asp, barbel, pike perch, catfish.

sturgeon photo

The waters of the Caspian Sea are the main and main habitat of sturgeon representatives on the entire planet. Almost 80% of all sturgeon in the world live in the sea. Sharks and various predatory fish that pose any danger to humans do not live in this reservoir.

The flora of the Caspian Sea is represented by more than 700 species of lower plants (phytoplankton), as well as 5 species of higher ones (spiral and marine ruppy, comb pondweed, zoster, sea naiad). Here you can find various waterfowl. Some of them fly here for the winter from the north (waders, loons, gulls, geese, swans, ducks, geese), some fly from the south for nesting (eagles).

Characteristic

Let's get acquainted with the main characteristics of the Caspian Sea:

The length from north to south was approximately 1200 km;
The width of the basin from west to east is approximately 200-435 km;
The total area of the Caspian Sea is approximately 390,000 km2;
The volume of sea waters is 78,000 km3.
Maximum deep sea- about 1025m.
Water salinity averages up to 13.2%.

Sea level is located below the level of the World Ocean. The North of the Caspian Sea is characterized by a continental climate. The middle Caspian has a temperate climate. South part The sea is characterized by a subtropical climate. in winter average temperature in the north it varies from 8 to 10 degrees below zero, and in the south from 8 to 10 degrees above zero. In summer, the average temperature in the north is 24-25 degrees above zero, and in the south 26-27 degrees Celsius.

Caspian Sea. birds photo

To this day, scientists are debating: what status should the Caspian sea or lake be given? After all, this reservoir is closed and drainless. At the same time, this body of water prevails in size over some other seas.
The bottom at the deepest point is separated from the water surface of the Caspian Sea by a distance of more than a kilometer. The water level in the Caspian Sea is unstable and tends to decrease.
This reservoir had approximately 70 names, which were given to it by different tribes and peoples living on its banks.
There is a scientific theory that claims that the Caspian and Black Sea, were united into one sea in ancient times.
The Volga River provides the Caspian Sea with most of the river water.
Since the Caspian Sea is the main sturgeon habitat on the planet, most of the world's black caviar is produced here.
The waters of the Caspian reservoir are constantly renewed every 250 years. The name of the reservoir, according to legend, comes from the name of the tribe that lived on its banks.
The area of the Caspian Sea is larger than the area of Japan and slightly less than the area of Germany.
If this body of water is considered a lake, it will take third place in depth in the world, after Baikal and Tanganyika. The Caspian is also the largest lake on the planet.
The Caspian Sea is very rich in Natural resources. Oil, gas, limestone, salts, clay, stones and sand are mined here.
The Caspian Sea has recently faced the following environmental problems: Sea pollution. Oil is the main pollutant of the sea, suppressing the development of phytoplankton and phytobenthos. In addition to oil, phenols and heavy metals enter the Caspian Sea. All this leads to a decrease in oxygen production, resulting in death. big number fish and other organisms. Pollution also leads to illness of living organisms in the sea. Poaching is one of the main reasons for the sharp decline in sturgeon catches. Changes in natural biogeochemical cycles. Construction on the Volga deprives fish of natural habitats.
The Caspian Sea is very important object in the field of shipping and economics. This body of water is absolutely closed and isolated from the world ocean. This is the distinctive uniqueness of the Caspian Sea.

Caspian Sea - the largest lake on Earth, endorheic, located at the junction of Europe and Asia, called a sea because of its size, as well as because its bed is composed of oceanic-type crust. The water in the Caspian Sea is salty, 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.

Geographical position

The Caspian Sea is located at the junction of two parts of the Eurasian continent - Europe and Asia. 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° c. d.). 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 runs along the line of the island. Chechen - Cape Tyub-Karagansky, between the Middle and Southern Caspian Sea - along the line of the island. Residential - Cape Gan-Gulu. The area of the Northern, Middle and Southern Caspian Sea is 25, 36, 39 percent, respectively.

The length of the coastline of 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 channels 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. The east coast is dominated by limestone shores 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. The territory adjacent to the Caspian Sea is called the Caspian region.

Peninsulas of the Caspian Sea

Large peninsulas of the Caspian Sea:

Agrakhan Peninsula
The Absheron Peninsula, located on the western coast of the Caspian Sea in the territory of Azerbaijan, at the northeastern end Greater Caucasus, on its territory the cities of Baku and Sumgayit are located
Buzachi
Mangyshlak, located on the eastern coast of the Caspian Sea, on the territory of Kazakhstan, on its territory is the city of Aktau
Miankale
Tyub-Karagan

Islands of the Caspian Sea

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

Ashur-Ada
Garasu
Boyuk-Zira
Zyanbil
Cure Dashi
Khara-Zira
Ogurchinsky
Sengi-Mugan
Seal
Seal Islands
Chechen
Chygyl

Bays of the Caspian Sea

Large bays of the Caspian Sea:

Agrakhan Bay
Kizlyar Bay
Dead Kultuk (formerly Komsomolets, formerly Tsesarevich Bay)
Kaydak
Mangyshlaksky
Kazakh
Kenderli
Turkmenbashi (bay) (formerly Krasnovodsk)
Turkmen (bay)
Gizilagach (formerly Kirov Bay)
Astrakhan (bay)
Hasan-kuli
Gizlar
Hyrcanus (formerly Astarabad)
Anzeli (formerly Pahlavi)
Kara-Bogaz-Gol

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 the Volga, Terek, Sulak, Samur (Russia), Ural, Emba (Kazakhstan), Kura (Azerbaijan), Atrek (Turkmenistan), Sefidrud (Iran) and others. Largest river, flowing into the Caspian Sea - 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.

Physiography

Area, depth, volume of water- the area and volume of water in the Caspian Sea varies significantly depending on fluctuations in water level. 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. In the same time Northern part The Caspian Sea is shallow, its maximum depth does not exceed 25 meters, and the average depth is 4 meters.

Water level fluctuations- the water level in the Caspian Sea is subject to significant fluctuations. According to modern science, over the past three thousand years, the magnitude of the change in the water level of the Caspian Sea has reached 15 meters. According to archeology and written sources, it is recorded high level Caspian Sea at the beginning of the 14th century. 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), the lowest in 1977 (−29.0 m), with 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. But in 2001, sea level began to rise again, and reached −26.3 m.

Water temperature- 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 off the coasts.

Water composition- 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 the chemical composition of 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.

Bottom relief- 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 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.

Climate- 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 air temperature 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 of +44 degrees was recorded on the east coast. The average annual precipitation is 200 millimeters, 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. The average annual wind 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, the environs of Makhachkala and Derbent, where the highest wave of 11 meters was recorded.

Currents- water circulation in the Caspian Sea is associated with drainage 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.

Economic development of the Caspian Sea

Mining of oil and gas-Many oil and gas fields are being developed in the Caspian Sea. Proven oil resources in the Caspian Sea are about 10 billion tons, total oil and gas condensate resources are estimated at 18-20 billion tons. Oil production in the Caspian Sea began in 1820, when the first oil well was drilled on the Absheron shelf near Baku. In the second half of the 19th century, oil production began on an industrial scale on the Absheron Peninsula, and then in other territories. In 1949, oil production from the bottom of the Caspian Sea began for the first time at Neftyanye Kamni. So, on August 24 of this year, Mikhail Kaverochkin’s team began drilling a well, which yielded the long-awaited oil on November 7 of the same year. In addition to oil and gas production, salt, limestone, stone, sand, and clay are also mined on the coast of the Caspian Sea and the Caspian shelf.

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 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 fishing of sturgeon and their caviar flourishes in the Caspian Sea.

Legal status of the Caspian Sea- after the collapse of the USSR, the division of the Caspian Sea for a long time was and still remains the subject of unresolved disagreements related to the division of the resources of the Caspian shelf - 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. The current legal regime of the Caspian 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.

(Caspian) - the largest on globe closed body of water, endorheic brackish lake. Located on the southern border of Asia and Europe. Due to the size, originality natural conditions and the complexity of hydrological processes, it is usually classified as a closed inland sea. The water level in the Caspian Sea is about 27 meters below the level of the World Ocean, the area is about 390 thousand square kilometers, the volume is about 78 thousand cubic kilometers. The greatest depth is 1025 meters. With a width of 200 to 400 kilometers, the sea extends along the meridian for 1030 kilometers.

More than 130 rivers flow into the Caspian Sea, the largest of which is the Volga, which connects it with the World Ocean.

The Caspian region is rich in hydrocarbon reserves - oil and gas. Among the biological resources of the Caspian Sea, sturgeon are of particular value, forming the basis of the world stock and gene pool, preserved and reproducing on Earth.

Five states have a coastline with the Caspian Sea: Russia - in the west and northwest, Kazakhstan - in the north, northeast and east, Iran - in the south, Azerbaijan - in the southwest, Turkmenistan - in the southeast.

IN Soviet time The Caspian Sea was practically an internal body of water within the borders of the USSR and only in the south washed the shores of Iran. The status of the Caspian Sea as an internal (inland) body of water established by the Soviet-Iranian treaties was practically recognized by the entire international community of states and was confirmed in the doctrine of international law.

The question of determining the legal status of the Caspian Sea, when the emergence of new subjects of international law - Azerbaijan, Kazakhstan and Turkmenistan - raised the question of delimiting the Caspian Sea between five countries. The difficulties in determining the status of the Caspian Sea are associated, in particular, with its recognition as a lake or sea, the delimitation of which is regulated by various provisions of international law.

Currently, the legal regime of the Caspian Sea is determined by the Treaty between the RSFSR and Persia of February 26, 1921 and the Treaty on Trade and Navigation between the USSR and Iran of March 25, 1940. These documents, based on the principle of “common water,” provide for freedom of navigation and fishing for the Caspian states (in the latter case, with the exception of a 10-mile fishing zone), and a ban on the navigation of ships flying the flags of non-Caspian countries. At the same time, the agreements do not regulate issues of subsoil use, environmental protection and military activities. In addition, their effectiveness is not recognized by all the newly emerged Caspian states.

In order to develop a Convention on the legal status of the Caspian Sea, in 1996, by decision of the foreign ministers of the five Caspian littoral states, a Special Working Group (SWG) was formed at the level of deputy foreign ministers.

Negotiations on the development of a Convention on the Legal Status of the Caspian Sea are being held within the framework of the AWG, as well as at bilateral and trilateral consultations. The agenda of the meetings also includes issues of interaction in the development of biological and mineral resources, navigation, ensuring security and preserving the Caspian ecosystem.

Coordination of draft sectoral international agreements on the Caspian theme is carried out at the level of representatives of the relevant government bodies of the parties.

July 6, 1998 between Russian Federation and the Republic of Kazakhstan concluded an Agreement on the delimitation of the bottom of the northern part of the Caspian Sea in order to exercise sovereign rights to subsoil use and on May 13, 2002 the Protocol to this Agreement.

On November 29, 2001 and February 27, 2003, the Agreement was concluded between the Republic of Kazakhstan and the Republic of Azerbaijan on the delimitation of the bottom of the Caspian Sea and the Protocol thereto, respectively.

It might be useful to read: