Why is the Caspian Sea so named and why is it called a lake. Caspian states: borders, map. Which countries are washed by the Caspian Sea

The Caspian Sea is the world's largest endorheic body of water at a level of 28.5 m below the level of the World Ocean. The Caspian Sea stretches from north to south for almost 1200 km, the average width is 320 km, the length of the coastline is about 7 thousand km. The area of ​​the Caspian Sea as a result of lowering the level decreased from 422 thousand km2 (1929) to 371 thousand km2 (1957). The volume of water is about 76 thousand km3, the average depth is 180 m. The coefficient of indentation of the coast is 3.36. The largest bays: Kizlyar, Komsomolets, Kara-Bogaz-Gol, Krasnovodsk, Mangyshlak.

There are about 50 islands with a total area of ​​350 km2. The most significant of them: Kulaly, Tyuleniy, Chechen, Zhiloy. More than 130 rivers flow into the Caspian Sea. The rivers Volga, Ural, Emba, Terek (total annual flow of 88% of the total river flow into the sea) flow into the northern part of the sea. On its western coast, the Sulak, Samur, Kura and other smaller rivers provide 7% of the total runoff. The remaining 5% of the flow is supplied by the rivers of the Iranian coast.

The relief of the bottom of the Caspian Sea

Climate in the Caspian Sea

In the northern and middle parts of the Caspian Sea, from October to April, the winds of the eastern quarter prevail, and from May to September, the winds of the northwestern rhumbs prevail. In the southern part of the Caspian Sea, the monsoon character of the winds is clearly expressed.

The long-term average air temperature of the warm months (July-August) over the entire sea is 24-26°C. The absolute maximum (up to 44°C) is noted on the east coast. On average, 200 mm of precipitation falls over the sea per year, with 90-100 mm on the arid eastern coast and 1700 mm in the subtropical southwestern part of the coast. Evaporation in most of the water area is about 1000 mm/year, and in the eastern part of the South Caspian and in the area of ​​the Apsheron Peninsula up to 1400 mm/year.

Hydrological regime

The maximum wave height (11 m) is observed in the area of ​​the Apsheron threshold. The water temperature of the surface layer of the sea in August is about 24-26 ° C in the North and Middle Caspian, up to 29 ° C in the South, 32 ° C in the Krasnovodsk Bay and over 35 ° C in the Kara-Bogaz-Gol Bay. In July-August, upwelling and associated temperature drops to 8-10°C are observed off the eastern shores.

Ice formation in the northern part of the Caspian Sea begins in December, and the ice remains for 2–3 months. In cold winters, drifting ice is carried south to the Absheron Peninsula.
Isolation from the World Ocean, the influx of river waters and the precipitation of salts as a result of intense evaporation in the Kara-Bogaz-Gol Bay determine the peculiarity of the salt composition of the Caspian Sea water - a reduced content of chlorides and an increased concentration of carbonates in comparison with the waters of the World Ocean. The Caspian Sea is a brackish water basin, the salinity of which is three times less than the normal ocean.

The average salinity of the waters of the northwestern part of the Caspian Sea is 1-2 ppm, in the region of the northern border of the Middle Caspian 12.7-12.8 ppm, and in the South Caspian 13 ppm, the maximum salinity (13.3 ppm) is observed near the eastern shores. In the Gulf of Kara-Bogaz-Gol, the salinity is 300 ppm; In the Northern and Southern Caspian, due to the reduction in inflow and salinization during ice formation, salinity increases in winter. In the South Caspian at this time, salinity decreases due to a decrease in evaporation. In summer, an increase in river flow causes a decrease in the salinity of waters in the North and Middle Caspian, and increasing evaporation leads to an increase in the salinity of the waters of the South Caspian. Changes in salinity from the surface to the bottom are small. Therefore, seasonal fluctuations in temperature and salinity of water, causing an increase in density, determine the winter vertical circulation of water, which in the Northern Caspian extends to the bottom, and in the Middle Caspian to a depth of 300 m. in winter, the waters of the Middle Caspian through the Apsheron threshold and the sliding of cooled waters of high salinity from the eastern shallow water. Studies have shown that due to the increase in water salinity over the past 25 years, the mixing depth has significantly increased, the oxygen content has correspondingly increased, and hydrogen sulfide contamination of deep waters has disappeared.

Tidal fluctuations in the level of the Caspian Sea do not exceed 3 cm. about 0.7 m. The range of seasonal level fluctuations is about 30 cm. A characteristic feature of the hydrological regime of the Caspian Sea is sharp interannual fluctuations in the average annual level. The average level from zero of the Baku footstock for a century (1830-1930) was 326 cm. The highest level (363 cm) was observed in 1896. cm. In the last decade, the level of the Caspian has stabilized at low levels with interannual fluctuations of the order of ±20 cm. Fluctuations in the level of the Caspian Sea are associated with climate changes over the entire basin of this sea.

To prevent a further drop in sea level, a system of measures is being developed. There is a project to transfer the waters of the northern rivers Vychegda and Pechora to the Volga river basin, which will increase the flow by about 32 km3. A project was developed (1972) to regulate the flow of Caspian waters into the Kara-Bogaz-Gol Bay.

The Caspian Sea is the largest 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 below the level of 28m. The water in the Caspian Sea has less 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 from 6500 to 6700 km, and if you take it together with the islands, then more than 7000 km.

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

Bottom relief

The bottom relief is divided into three main forms. Shelf in the northern part, the average depth here is from 4 to 9 m, the maximum depth is 24 m, which gradually increases and reaches 100 m. The continental slope in the middle part drops to 500 m. The Mangyshlak threshold separates the northern part from the middle part. Here one of the deepest places is the 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 northwest, the length of the coast of 695 km is the territory of Russia. Most of the coastline with a length of 2320 km belongs to Kazakhstan in the east and northeast. Turkmenistan has 1,200 km in the southeast, Iran has 724 km in the south, and Azerbaijan has 955 km of coastline in the southwest.

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

The main ports are Baku in Azerbaijan; Makhachkala in ; Aktau in Kazakhstan; Olya in Russia; Nowshahr, Bander-Torkemen and Anzeli in Iran.

The largest bays of the Caspian Sea: Agrakhan, Kizlyar, Kaydak, Kazakh, Dead Kultuk, Mangyshlak, Hasan-kuli, Turkmenbashi, Kazakh, Gyzlar, Enzeli, 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, and a culvert had to be built. Through it, up to 25 km3 of water enters the lake annually.

Water temperature

The greatest fluctuations in temperature 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. The optimum warming up of the water occurs in July-August, in shallow water the temperature reaches 320. But at this time, north-western 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 drops. 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. On the east coast, the temperature is always higher than on the west. Once on the east coast recorded 44 degrees.

The composition of the Caspian waters

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

Storms are frequent in shallow water areas. They occur 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 a rapid pollution of water by oil products and phenols. Their level already exceeds the permissible level.

Minerals

Back in the 19th century, the beginning of hydrocarbon production was laid. These are the main natural resources. There are also mineral, balneological biological resources here. Today, in addition to gas and oil production, sea-type salts (Astrakhanite, mirabalite, halite), sand, limestone, and clay are mined on the shelf.

Animal and plant world

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

From plants, blue-green algae, brown, red can be noted. Zostera and ruppia also grow, they are classified as flowering algae.

The plankton brought into the sea by birds begins to bloom in spring, the sea is literally covered with greenery, and rhizosolation during flowering paints most of the sea territory in yellow-green color. The accumulation of rhizosolenia is so dense that even waves can calm down. 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, ducks winter, birds such as pelicans, herons, flamingos arrange nesting.

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 because of expensive caviar.

Governments are investing a lot of money to improve the situation. They purify sewage, build factories for breeding fish, despite these measures, it is necessary to limit the production of sturgeon.

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 drainless 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, at present - about 28 m below the level of the World Ocean.
Square Caspian Sea currently - approximately 371,000 sq. km, maximum depth - 1025 m.

coastline length Caspian Sea estimated at about 6500 - 6700 kilometers, with the islands - up to 7000 kilometers. coast Caspian Sea in most of its territory - low-lying and smooth. In the northern part, the coastline is indented by water channels and islands of the Volga and Ural deltas, the shores are low and swampy, and the water surface is covered with thickets in many places. The east coast is dominated by limestone shores adjacent to semi-deserts and deserts. The most winding coasts are on the west coast in the area of ​​the Apsheron Peninsula and on the east coast in the area of ​​the Kazakh Gulf and Kara-Bogaz-Gol.

IN Caspian Sea 130 rivers flow into it, of which 9 rivers have a mouth in the form of a delta. 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 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, the length of the coastline - 724 kilometers
Azerbaijan - in the southwest, the length of the coastline is 955 kilometers

Water temperature

is subject to significant latitudinal changes, most pronounced 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 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 near the western coast is 1 - 2 °C higher than that of the eastern coast, 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 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 is 44 degrees.

Animal world

The fauna of the Caspian is represented by 1809 species, of which 415 are vertebrates. IN Caspian Sea 101 species of fish have been registered, and most of the world's sturgeon stocks are concentrated in it, as well as such freshwater fish as roach, carp, 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 coast is represented by 728 species. From plants to Caspian Sea algae predominate - blue-green, diatoms, red, brown, char and others, from flowering ones - zoster and ruppia. By origin, the flora belongs mainly to the Neogene age, however, some plants were brought into Caspian Sea by a person consciously 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 on other territories.

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

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 vital activity of coastal cities, as well as the flooding of individual facilities due to an increase in the level Caspian Sea. Predatory harvesting of sturgeons and their caviar, rampant poaching lead to a decrease in the number of sturgeons and forced restrictions on their production and export.

Many geographical names can mislead people who are not fond of geography. Could it be that the object marked on all maps as the sea is in fact 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 Azov seas. About 6,000,000 years ago, due to the rise of the Caucasus Mountains and the lowering of the water level in the Mediterranean Sea, it split, forming four different seas.

The Caspian is inhabited by many representatives of the fauna of Azov, which once again confirms that once these reservoirs were one. 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 Caspians. They inhabited its shores in the first millennia BC and were engaged in horse breeding. But over the long hundreds of years of its existence, this sea has had many names. It was called Derbent, Sarai, Girkan, Sigay, Kukkuz. Even in our time, for the inhabitants of Iran and Azerbaijan, this lake is called Khazar.

Geographic 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. The total area of ​​the reservoir is more than 370,000 square kilometers and is divided into three climatic and geographical zones:

1. Northern
2. Average
3. South Caspian

The water area has 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 Absheron Islands. About one hundred and thirty rivers flow into the Caspian, 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 oceans. In the case of the Caspian, this is not the reality. From the nearest sea, the Black Sea, the Caspian Sea is separated by almost 500 km of land. This is a completely enclosed reservoir. The main differences of the seas:

• The seas can be fed by water arteries - rivers.
• The outer seas are directly connected with the ocean, that is, they have access to it.
• The 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 characteristic of seas rather than lakes. In terms of area, it surpasses even Azov. Also, the fact that not a single lake washes the shores of five states at once played a significant role.

It should be noted that the structure of the bottom of the Caspian Sea belongs to the oceanic type. This happened due to the fact that it was once part of the ancient oceans.

Compared to other seas, the percentage of salt saturation in it is very weak and does not exceed 0.05%. The Caspian 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 largest lake in the world. Its waters are not subject to international maritime laws. The territory of the 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 spike. 90% of the world's sturgeon catch goes to the Caspian Sea.

Interesting features:

• Scientists around the world have not come to an unambiguous opinion why the Caspian Sea is considered a lake. Some experts even suggest considering it a "lake-sea" or "inland" sea, like the Dead Sea in Israel;
• The deepest point of the Caspian is more than one kilometer;
• Historically, it is known that the general water level in the reservoir has changed more than once. The exact reasons for this are still not understood;
• This is the only body of water separating Asia and Europe;
• The largest waterway that feeds the lake is the Volga River. It is she who 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 loses 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;
• The territory of Japan is smaller than the area of ​​the Caspian Sea.

Ecological situation

Intervention in 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 catching of valuable species of fish 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 the water level has fallen by seven centimeters since 1996. By 2015, the fall was about one and a half meters, and the water continues to fall.

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

It is known that long before the onset of global warming, the water level in the Caspian was undergoing changes. The water stayed and then fell. Scientists still cannot say exactly why this happened.

On Sunday, August 12, in Kazakhstan's Aktau, the presidents of Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan signed the Convention on the Legal Status of the Caspian Sea. Previously, its status was regulated by the Soviet-Iranian treaties, in which the Caspian Sea was defined as a closed (inland) sea, and each Caspian state had sovereign rights to a 10-mile zone and equal rights to the rest of the sea.

Now, according to the new convention, each country has its own territorial waters (zones 15 miles wide). In addition, the provisions of the UN Convention on the Law of the Sea of ​​1982 will not apply to the Caspian Sea, the seabed will be delimited into sectors, as is done by neighbors on the seas, and sovereignty over the water column will be established on the basis of the principle that this is a lake.

Why is the Caspian considered neither a lake nor a sea?

To be considered a sea, the Caspian must have access to the ocean, this is one of the most important conditions for a body of water to be called a sea. But the Caspian has no access to the ocean, so it is considered a closed body of water, not connected to the oceans.

The second feature that distinguishes sea water from lake water is their high salinity. The water in the Caspian Sea is indeed salty, but in terms of its salt composition it occupies an intermediate position between a river and an ocean. In addition, in the Caspian Sea, salinity increases towards the south. The Volga delta contains from 0.3‰ salts, and in the eastern regions of the South and Middle Caspian, salinity already reaches 13-14‰. And if we talk about the salinity of the World Ocean, then it averages 34.7 ‰.

Due to the specific geographical and hydrological characteristics, the reservoir received a special legal status. The summit participants decided that the Caspian Sea is an inland water body that has no direct connection with the World Ocean, and therefore cannot be considered a sea, and at the same time, due to its size, water composition and bottom features, it cannot be considered a lake.

What has been achieved since the signing of the Convention?

The new treaty expands the possibilities for cooperation between countries, and also involves limiting any military presence of third countries. According to political scientist, director of the Institute of Recent States Alexei Martynov, the main achievement of the last summit is that its participants managed to stop any talk about the possible construction of NATO military bases and infrastructure facilities in the Caspian Sea.

“The most important thing that has been achieved is to fix that the Caspian will be demilitarized for all the Caspian states. There will be no other military, except for those representing the countries that have signed the Caspian Agreement. This is a fundamental and main issue that was important to fix. Everything else, that is divided in proportion to the zone of influence, the zone of extraction of bioresources, the zone of extraction of shelf resources was not so important. As we remember, in the last twenty years, the military has been actively striving for the region. The US even wanted to build its own military base there,” says Martynov.

In addition to the distribution of the shares of each country in the oil and gas fields of the Caspian basin, the Convention also provides for the construction of pipelines. As stated in the document, the rules for their laying provide for the consent of only neighboring countries, and not all countries of the Caspian Sea. After the signing of the agreement, Turkmenistan, in particular, stated that it was ready to lay pipelines along the bottom of the Caspian Sea, which would allow it to export its gas through Azerbaijan to Europe. The consent of Russia, which previously insisted that the project could only be implemented with the permission of all five Caspian states, is no longer required. The gas pipeline is planned to be connected in the future to the Trans-Anatolian gas pipeline, through which natural gas will go through the territory of Azerbaijan, Georgia and Turkey to Greece.

“Turkmenistan is not a foreign country to us, but our partner, a country that we consider very important for us in the post-Soviet space. We cannot be against them receiving an additional impetus for development through such pipeline projects. Gas has been coming from Turkmenistan and other countries through a different pipeline system for a long time, somewhere it even mixes with Russian gas, and there is nothing wrong with that. If this project works, then everyone will benefit, including Russia. In no case should the project be considered as a kind of competition. The European market is so big and insatiable, I mean the energy market, that there is enough space for everyone,” says Martynov.

Today, almost all Turkmen gas is supplied to China, where Russia also intends to supply natural gas. For this purpose, in particular, a large-scale project for the construction of the Power of Siberia gas pipeline is being implemented. Thus, the geography of gas supplies from both countries may expand - Turkmenistan will gain access to the European market, and Russia will be able to increase its gas supplies to China.