Why can the Caspian Sea be called neither a sea nor a lake? Caspian lake. Why is the Caspian Lake called a sea? What large rivers flow into the Caspian Sea

The Caspian Sea is the most big lake on planet 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 catchment area it is second only to Siberian rivers flowing into the Caspian Sea, such as the Ob, Lena, Yenisei, and Irtysh. The source from where 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, Saraya. The mouth is divided by branches, the largest of which are: Bolda, Bakhtemir, Buzan. Astrakhan is 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. Its pool has a fairly 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; hydroelectric power stations, urban settlements Sulak and Dubki are located on it, as well as small town 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 high mountains made of clayey shales and sandstones, which is why the water here is muddy. 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 of the Caucasus 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 water turbidity 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 unusual look: the bed here is raised above the valley, along appearance 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 encountering a plateau along the way, it makes a sharp turn and continues to flow in a north-west 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. This is an inland European river, but its upper reaches east of the Ural Range are Asian territory.

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 used by humans 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.

I was resting somehow in the camp. It's no secret that almost every day competitions are held there to entertain children and youth. So here it is. Was with us quiz. Question: “Which lake is the largest?” One guy of about fifteen was the first to raise his hand and answer: “Baikal.” The strangest thing was that his answer was counted as correct! How so? Isn't the Caspian Sea the largest lake? Now I will explain to you.

How to distinguish a sea from a lake

I'll list several signs by which a body of water is identified as a sea.

1. Rivers can flow into the sea.

2. The outer sea has direct access to the ocean.

3. If the sea is internal, then it is connected by straits with other seas or directly with the ocean.


Does the Caspian Sea fit sea parameters?

Need to check does the Caspian Sea have signs of a sea. into it really rivers flow in, but they flow into many bodies of water: seas, lakes, oceans, and other rivers. The Caspian Sea is surrounded from all sides by land. Is this really inland sea? Then it must connect with Black or Seas of Azov somehow strait. Strait Same No. Exactly due to the lack of access to the World Ocean, the Caspian Sea is considered a lake.

“But why was it called the sea then, if it is a lake?”- you ask. Answer very simple: because of his large size and salinity. In fact, The Caspian Sea is several times larger than the Azov Sea and almost equal in size to the Baltic Sea.

Great! The problem with the quiz has been resolved. Judge to hell!!!

Well then, I told, that the Caspian Sea In fact - lake. Now I want to you provide small selection interesting facts about this lake.


1. The Caspian Sea is below sea level (-28 m), which once again proves that this is a lake.

2. BC near the lake area lived nomadic Caspian tribes,in honor of which he was nicknamed Caspian.

3. This the deepest enclosed body of water on the planet.

4. Many people think that the name of the group “Caspian Cargo” is related to the Caspian Sea. In some ways they are right ( No). In fact the expression “Caspian cargo” can mean any illegal cargo.

5.Caspian Sea Fine suitable for tourism. During the USSR it was built here large number sanatoriums. Today or here you can see many hotels, water parks and beaches.

The Caspian Sea is called 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 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. Shelf in the northern part, average depth here 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-Torqemen and Anzali in Iran.

The most large bays 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's 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. On east coast The temperature is always higher than in the west. 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, salts are mined on the shelf marine type(astrakhanite, mirabalite, halite), sand, limestone, clay.

Fauna and flora

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.

Plankton brought into the sea by birds begins to bloom in the spring, the sea is literally covered with greenery, and during flowering, rhizosolina colors most of the sea area yellow-green. 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.

There are still disputes about the status of the Caspian Sea. The fact is that, despite its generally accepted name, it is still the largest endorheic lake in the world. It was called the sea because of the features of the structure of the bottom. It is formed by oceanic crust. In addition, the water in the Caspian Sea is salty. As at sea, there are often storms and strong winds that raise high waves.

Geography

The Caspian Sea is located at the junction of Asia and Europe. In its shape, it resembles one of the letters of the Latin alphabet - S. From south to north, the sea stretches for 1200 km, and from east to west - from 195 to 435 km.

The territory of the Caspian Sea is heterogeneous in its physical and geographical conditions. In this regard, it is conventionally divided into 3 parts. These include the Northern and Middle, as well as the Southern Caspian.

Coastal countries

Which countries is washed by the Caspian Sea? There are only five of them:

  1. Russia, located in the northwest and west. The length of the coastline of this state along the Caspian Sea is 695 km. Kalmykia, Dagestan and the Astrakhan region, which are part of Russia, are located here.
  2. Kazakhstan. It is a country on the shores of the Caspian Sea, located in the east and northeast. The length of its coastline is 2320 km.
  3. Turkmenistan. The map of the Caspian states indicates that this country is located in the southeast of the water basin. The length of the line along the coast is 1200 km.
  4. Azerbaijan. This state, stretching 955 km along the Caspian Sea, washes its shores in the southwest.
  5. Iran. A map of the Caspian states indicates that this country is located on the southern shores of an endorheic lake. At the same time, its length maritime boundaries is 724 km.

Is the Caspian Sea?

The dispute over what to call this unique body of water has not yet been resolved. And it is important to answer this question. The fact is that all countries on the Caspian Sea have this region own interests. However, the governments of five states have not been able to resolve the question of how to divide this huge body of water for a long time. The most important controversy revolved around the name. Is the Caspian Sea a sea or a lake? Moreover, the answer to this question is of no more interest to geographers. First of all, politicians need it. This is due to the application of international law.

Caspian states such as Kazakhstan and Russia believe that their borders in this region are washed by the sea. In this regard, representatives of the two indicated countries insist on the application of the UN Convention adopted in 1982. It concerns the law of the sea. The provisions of this document state that coastal states are allocated a twelve-mile water zone along it. In addition, the country is granted the right to economic maritime territory. It is located two hundred miles away. The coastal state also has rights to However, even the widest part of the Caspian Sea is narrower than the distance specified in the international document. In this case, the middle line principle can be applied. At the same time, the Caspian states, which have the greatest length of coastal borders, will receive a large maritime territory.

Iran has a different opinion on this matter. Its representatives believe that the Caspian Sea should be divided fairly. In this case, all countries will get twenty percent of the maritime territory. The position of official Tehran can be understood. With this solution to the issue, the state will manage a larger zone than when dividing the sea along the middle line.

However, the Caspian Sea changes its water level significantly from year to year. This does not allow us to determine its median line and divide the territory between states. Countries such as Azerbaijan, Kazakhstan and Russia have signed an agreement among themselves defining the bottom zones in which the parties will exercise their economic rights. Thus, a certain legal truce has been achieved in the northern territories of the sea. Southern countries The Caspian Sea has not yet come to a common decision. However, they do not recognize the agreements reached by their northern neighbors.

Is the Caspian a lake?

Adherents of this point of view proceed from the fact that the reservoir, located at the junction of Asia and Europe, is closed. In this case, it is impossible to apply a document on the norms of international maritime law to it. Proponents of this theory are convinced that they are right, citing the fact that the Caspian Sea does not have a natural connection with the waters of the World Ocean. But here another difficulty arises. If the lake is the Caspian Sea, the boundaries of states according to what international standards should be determined on it water spaces? Unfortunately, such documents have not yet been developed. The fact is that the issues of the international lake have not been discussed anywhere by anyone.

Is the Caspian Sea a unique body of water?

In addition to those listed above, there is another, third point of view on the ownership of this amazing body of water. Its supporters are of the opinion that the Caspian Sea should be recognized as an international water basin, belonging equally to all countries bordering it. In their opinion, the region’s resources are subject to joint exploitation by countries bordering the reservoir.

Solving security problems

The Caspian states are doing everything possible to eliminate all existing disagreements. And in this matter, positive developments can be noted. One of the steps towards solving problems related to the Caspian region was the agreement signed on November 18, 2010 between all five countries. It concerns issues of security cooperation. In this document, the countries agreed on joint activities to eliminate terrorism, drug trafficking, smuggling, poaching, money laundering, etc. in the region.

Environmental protection

Particular attention is paid to solving environmental issues. The territory in which the Caspian states and Eurasia are located is a region under the threat of industrial pollution. Kazakhstan, Turkmenistan and Azerbaijan dump waste from energy exploration and production into the Caspian waters. Moreover, it is in these countries that there are a large number of abandoned oil wells that are not exploited due to their unprofitability, but nevertheless continue to have an adverse impact on the environmental situation. As for Iran, it is dumping sea ​​waters agricultural waste and runoff. Russia threatens the ecology of the region with industrial pollution. This is due to economic activity, which unfolded in the Volga region.

Countries on the Caspian Sea have made some progress in solving problems environment. Thus, since August 12, 2007, the Frame Convection has been in force in the region, with the goal of protecting the Caspian Sea. This document develops provisions on the protection of biological resources and regulation of anthropogenic factors affecting the aquatic environment. According to this convection, the parties must interact when carrying out measures to improve the environmental situation in the Caspian Sea.

In 2011 and 2012, all five countries signed other documents significant for the protection of the marine environment. Among them:

  • Protocol on cooperation, response and regional preparedness in the event of oil pollution incidents.
  • Protocol concerning the protection of the region against pollution from land-based sources.

Development of gas pipeline construction

Today, another problem remains unresolved in the Caspian region. It concerns the laying of this idea. This idea is an important strategic task of the West and the United States, which continue to look for alternative energy sources to Russian ones. That is why when deciding this issue the parties do not turn to countries such as Kazakhstan, Iran and, of course, the Russian Federation. Brussels and Washington supported the statement made in Baku on November 18, 2010 at the summit of the heads of the Caspian countries. He expressed the official position of Ashgabat regarding the laying of the pipeline. Turkmen authorities believe that the project should be implemented. At the same time, only those states on whose bottom territories it will be located must give their consent to the construction of the pipeline. And this is Turkmenistan and Azerbaijan. Iran and Russia opposed this position and the project itself. At the same time, they were guided by the issues of protecting the Caspian ecosystem. To date, construction of the pipeline is not underway due to disagreement between project participants.

Holding the first summit

Countries on the Caspian Sea are constantly looking for ways to solve the problems that have arisen in this Eurasian region. For this purpose, special meetings of their representatives are organized. Thus, the first summit of the heads of the Caspian states took place in April 2002. Its venue was Ashgabat. However, the results of this meeting did not live up to expectations. The summit was considered unsuccessful due to Iran's demands to divide the sea area into 5 equal parts. Other countries categorically opposed this. Their representatives defended their own point of view that the size of national waters should correspond to the length that coastline states.

The unsuccessful holding of the summit was also provoked by a dispute between Ashgabat and Baku over the ownership of three oil fields located in the center of the Caspian Sea. As a result, the heads of five states did not develop consensus on none of all the issues raised. However, an agreement was reached to hold a second summit. It was supposed to take place in 2003 in Baku.

Second Caspian Summit

Despite the existing agreements, the planned meeting was postponed every year. The heads of the Caspian states gathered for the second summit only on October 16, 2007. It was held in Tehran. At the meeting, current issues related to the definition of legal status unique body of water, which is the Caspian Sea. The borders of states within the division of the water area were previously agreed upon during the development of the draft of the new convention. Problems of security, ecology, economics and cooperation of coastal countries were also raised. In addition, the results of the work that the states carried out after the first summit were summed up. In Tehran, representatives of the five states also outlined ways for further cooperation in the region.

Meeting at the third summit

Once again, the heads of the Caspian countries met in Baku on November 18, 2010. The result of this summit was the signing of an agreement to expand cooperation regarding security issues. During the meeting, it was pointed out that which countries are washed by the Caspian Sea, only those should ensure the fight against terrorism, transnational crime, weapons proliferation, etc.

Fourth summit

Once again, the Caspian states raised their problems in Astrakhan on September 29, 2014. At this meeting, the presidents of the five countries signed another statement.

In it, the parties recorded the exclusive right of the coastal countries to deploy armed forces in the Caspian Sea. But even at this meeting the status of the Caspian Sea was not finally regulated.

The Caspian Sea is the largest on Earth closed lake, located at the junction of Europe and Asia, called the sea due to the fact that its bed is composed of oceanic-type crust. The Caspian Sea is an endorheic 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, according to 2009 data it was 27.16 m below sea level. 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, from west to east - from 195 to 435 kilometers, on average 310-320 kilometers. 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 west coast in the area Absheron Peninsula and on the east coast in the area of ​​the Kazakh Gulf and Kara-Bogaz-Gol. The territory adjacent to the Caspian Sea is called the Caspian region.

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. 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 water temperature difference is about 10 °C . For shallow 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.

Fauna and flora The fauna of the Caspian Sea is represented by 1809 species, of which 415 are vertebrates. 101 species of fish are registered in the Caspian Sea, 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 inhabited by marine mammal- Caspian seal. 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, but some plants were brought into the Caspian Sea by humans deliberately or on the bottoms of ships.

Minerals 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. 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, salt, limestone, stone, sand, and clay are also mined on the coast of the Caspian Sea and the Caspian shelf.