The Caspian Sea is cold or... Caspian Sea. Small sea or huge lake? (3 photos). Sea level fluctuations

The Caspian Sea is one of the largest salty bodies of water on Earth, located at the junction of Europe and Asia. Its total area is about 370 thousand square meters. km. The reservoir receives more than 100 water streams. The largest rivers flowing into the Volga, Ural, Emba, Terek, Sulak, Samur, Kura, Atrek, Sefidrud.

The Volga River - the pearl of Russia

The Volga is a river flowing on the territory of the Russian Federation, partially crossing Kazakhstan. Belongs to the category of the largest and long rivers on the ground. Total length The Volga is more than 3500 km. The river originates in the village of Volgoverkhovye, Tver region, located on the river. After that, it continues its movement through the territory Russian Federation.

It flows into the Caspian Sea, but does not have direct access to the World Ocean, so it is classified as internal drainage. The watercourse receives about 200 tributaries and has more than 150 thousand outlets. Today, reservoirs have been built on the river to regulate flow, which has sharply reduced fluctuations in water levels.

The river's fisheries are varied. In the Volga region, melon growing predominates: the fields are occupied by grain and industrial crops; table salt is extracted. Oil and gas deposits have been discovered in the Urals region. The Volga is the largest river flowing into the Caspian Sea, so it is of great importance for Russia. The main transport structure that allows you to cross this stream is the longest in Russia.

Ural - river in Eastern Europe

The Ural, like the Volga River, flows on the territory of two states - Kazakhstan and the Russian Federation. Historical name - Yaik. It originates in Bashkortostan at the top of the Uraltau ridge. The Ural River flows into the Caspian Sea. Its pool is the sixth largest in the Russian Federation, and its area is more than 230 square meters. km. Interesting fact: The Ural River, contrary to popular belief, belongs to the internal European river, and only its upper course in Russia belongs to Asia.

The mouth of the watercourse gradually becomes shallow. At this point the river divides into several branches. This feature is characteristic along the entire length of the channel. During floods, you can observe how the Ural overflows its banks, in principle, like many other Russian rivers flowing into the Caspian Sea. This is especially observed in places with a gently sloping coastline. Flooding occurs at a distance of up to 7 meters from the riverbed.

Emba - river of Kazakhstan

Emba is a river flowing in the territory of the Republic of Kazakhstan. The name comes from the Turkmen language, literally translated as “valley of food”. The river basin has an area of 40 thousand square meters. km. The river begins its journey in the Mugodzhary mountains and, as it flows, it gets lost among the swamps. When asking which rivers flow into the Caspian Sea, we can say that in high-flow years the Emba reaches its basin.

For coastline rivers are being mined natural resources, like oil and gas. The issue of passing the border between Europe and Asia along the Emba watercourse, as in the case of the river. Ural, open topic and today. The reason for this is natural factor: mountains Ural ridge, which are the main guideline for drawing boundaries, disappear, forming a homogeneous terrain.

Terek - mountain water stream

Terek - river North Caucasus. The name is literally translated from Turkic as “poplar”. The Terek flows from the glacier of Mount Zilga-Khokh, located in the Trusovsky Gorge Caucasian ridge. passes through the lands of many states: North Ossetia, Georgia, Stavropol Territory, Kabardino-Balkaria, Dagestan and the Chechen Republic. It flows into the Caspian Sea and Arkhangelsk Bay. The length of the river is just over 600 km, the basin area is about 43 thousand square meters. km. An interesting fact is that every 60-70 years the flow forms a new transit branch, while the old one loses its strength and disappears.

The Terek, like other rivers flowing into the Caspian Sea, is widely used to satisfy human economic needs: it is used to irrigate the arid areas of the adjacent lowlands. There are also several hydroelectric power stations located on the water stream, the total average annual production of which is more than 200 million kWh. New additional stations are planned to be launched in the near future.

Sulak - water stream of Dagestan

Sulak is a river connecting the Avar Koisu and Andean Koisu streams. It flows through the territory of Dagestan. It begins in the Main Sulak Canyon and ends its journey in the waters of the Caspian Sea. The main purpose of the river is to supply water to two cities of Dagestan - Makhachkala and Kaspiysk. Also, several hydroelectric power stations are already located on the river, and new ones are planned to be launched to increase the generated power.

Samur - the pearl of Southern Dagestan

Samur is the second largest river in Dagestan. The name is literally translated from Indo-Aryan as “abundance of water.” It originates at the foot of Mount Guton; It flows into the waters of the Caspian Sea through two branches - Samur and Small Samur. The total length of the river is just over 200 km.

All rivers flowing into the Caspian Sea are of great importance for the territories through which they flow. Samur is no exception. The main purpose of using the river is to irrigate land and provide residents of nearby cities with drinking water. It is because of this that the waterworks and a number of the Samur-Divichi canal were built.

At the beginning of the twentieth century (2010), Russia and Azerbaijan signed an interstate agreement requiring both parties to rationally use the resources of the Samur River. The same agreement introduced territorial changes between these countries. The border of the two states has been moved to the middle of the hydroelectric complex.

Kura - the largest river in Transcaucasia

When wondering which rivers flow into the Caspian Sea, I would like to describe the Kuru stream. It flows on the land of three states at once: Turkey, Georgia, Azerbaijan. The length of the stream is more than 1000 km, the total area of the basin is about 200 thousand square meters. km. Part of the basin is located on the territory of Armenia and Iran. The source of the river is in the Turkish province of Kars, flowing into the waters of the Caspian Sea. The path of the river is thorny, laid among hollows and gorges, for which it received its name, which translated from the Mingrelian language means “gnaw”, that is, the Kura is a river that “gnaws” itself among the mountains.

There are many cities on it, such as Borjomi, Tbilisi, Mtskheta and others. It plays an important role in meeting the economic needs of the residents of these cities: hydroelectric power stations are being built, and the Mingachevir reservoir created on the river is one of the main fresh water reserves for Azerbaijan. Unfortunately, the ecological state of the stream leaves much to be desired: the level of harmful substances is several times higher than the permissible limits.

Features of the Atrek River

Atrek is a river located on the territory of Iran and Turkmenistan. It originates in the Turkmen-Kharasan mountains. Due to active use for economic needs for irrigation, the river has become shallow. For this reason, it reaches the Caspian Sea only during flood periods.

Sefidrud - high-water river of the Caspian Sea

Sefidrud is a major river of the Iranian state. Initially it was formed by the confluence of two water streams - Kyzyluzen and Shahrud. Now it flows out of the Shabanau reservoir and flows into the depths of the Caspian Sea. The total length of the river is more than 700 km. The creation of a reservoir became a necessity. It made it possible to minimize the risk of flooding, thereby protecting the cities located in the river delta. Water is used to irrigate land with total area more than 200 thousand hectares of land.

As can be seen from the presented material, water resources The lands are in unsatisfactory condition. The rivers flowing into the Caspian Sea are actively used by people to satisfy their needs. And this has a detrimental effect on their condition: watercourses are depleted and polluted. That is why scientists around the world are sounding the alarm and conducting active propaganda, calling for saving and conserving water on Earth.

Caspian lake is one of the most unique places on the ground. It keeps many secrets related to the history of the development of our planet.

Position on physical map

The Caspian Sea is an internal drainage salt Lake. The geographical location of the Caspian Lake is the continent of Eurasia at the junction of parts of the world (Europe and Asia).

The length of the lake shoreline ranges from 6500 km to 6700 km. Taking into account the islands, the length increases to 7000 km.

The coastal areas of the Caspian Lake are mostly low-lying. Their northern part is cut by the channels of the Volga and Ural. The river delta is rich in islands. The surface of the water in these areas is covered with thickets. Swampiness of large areas of land is noted.

The eastern coast of the Caspian Sea adjoins the On the shores of the lake there are significant deposits of limestone. The western and part of the eastern coasts are characterized by a winding coastline.

The Caspian Lake is represented on the map by its considerable size. The entire territory adjacent to it was called the Caspian Sea.

Some characteristics

The Caspian Lake has no equal on Earth in terms of its area and volume of water. It stretches from north to south for 1049 kilometers, and its longest length from west to east is 435 kilometers.

If we take into account the depth of the reservoirs, their area and volume of water, then the lake is comparable to the Yellow, Baltic and Black Seas. According to the same parameters, the Caspian Sea surpasses the Tyrrhenian, Aegean, Adriatic and other seas.

The volume of water available in the Caspian Lake is 44% of the supply of all lake waters on the planet.

Lake or sea?

Why is the Caspian Lake called a sea? Was it really the impressive size of the reservoir that became the reason for assigning such a “status”? More precisely, this became one of these reasons.

Others include the huge mass of water in the lake, the presence of large waves during stormy winds. All this is typical for real seas. It becomes clear why the Caspian Lake is called a sea.

But one of the main conditions that must exist in order for geographers to classify a body of water as a sea is not mentioned here. We are talking about a direct connection between the lake and the World Ocean. Exactly this condition The Caspian does not correspond.

Where the Caspian Lake is located, a depression was formed in the earth’s crust several tens of thousands of years ago. Today it is filled with the waters of the Caspian Sea. According to scientists, at the end of the 20th century, the water level in the Caspian Sea was 28 meters below the level of the World Ocean. The direct connection between the waters of the lake and the ocean ceased to exist approximately 6 thousand years ago. The conclusion from the above is that the Caspian Sea is a lake.

There is one more feature that distinguishes the Caspian Sea from the sea - the salinity of its water is almost 3 times lower than the salinity of the World Ocean. The explanation for this is that about 130 large and small rivers carry fresh water to the Caspian Sea. The Volga makes the most significant contribution to this work - it “gives” up to 80% of all water to the lake.

The river played another important role in the life of the Caspian Sea. It is she who will help find the answer to the question of why the Caspian Lake is called a sea. Now that man has built many canals, it has become a fact that the Volga connects the lake with the World Ocean.

History of the lake

Modern look and geographical position The Caspian Lake is caused by continuous processes occurring on the surface of the Earth and in its interior. There were times when the Caspian Sea was connected to Sea of Azov, and through it with the Mediterranean and Black. That is, tens of thousands of years ago the Caspian Lake was part of the World Ocean.

As a result of processes associated with the rise and fall of the earth's crust, mountains appeared that are located on the site of the modern Caucasus. They isolated a body of water that was part of a huge ancient ocean. Tens of thousands of years passed before the basins of the Black and Caspian Seas separated. But for a long time the connection between their waters was carried out through the strait, which was on the site of the Kuma-Manych depression.

Periodically, the narrow strait was either dried up or filled with water again. This happened due to fluctuations in the level of the World Ocean and changes in the appearance of the land.

In a word, the origin of the Caspian Lake is closely connected with general history formation of the Earth's surface.

The lake received its modern name because of the Caspian tribes that inhabited the eastern parts of the Caucasus and the steppe zones of the Caspian territories. Throughout the history of its existence, the lake has had 70 different names.

Territorial division of the lake-sea

The depth of the Caspian Lake is very different in different places. Based on this, the entire water area of the lake-sea was conditionally divided into three parts: the Northern, Middle and Southern Caspian.

Shallow water is Northern part lakes. The average depth of these places is 4.4 meters. The highest indicator is 27 meters. And on 20% of the entire area of the Northern Caspian Sea the depth is only about a meter. It is clear that this part of the lake is of little use for navigation.

The Middle Caspian has the greatest depth of 788 meters. The deep-water part is occupied by lakes. The average depth here is 345 meters, and the greatest is 1026 meters.

Seasonal changes at sea

Due to the large length of the reservoir from north to south climatic conditions Lakes on the coast are not the same. Seasonal changes in the areas adjacent to the reservoir also depend on this.

In winter, on the southern coast of the lake in Iran, the water temperature does not drop below 13 degrees. During the same period, in the northern part of the lake off the coast of Russia, the water temperature does not exceed 0 degrees. The Northern Caspian is covered with ice for 2-3 months of the year.

In summer, almost everywhere the Caspian Lake warms up to 25-30 degrees. Warm water, excellent sandy beaches, and sunny weather create excellent conditions for people to relax.

Caspian Sea on the political map of the world

There are five states on the shores of the Caspian Lake - Russia, Iran, Azerbaijan, Kazakhstan and Turkmenistan.

The western regions of the Northern and Middle Caspian Sea belong to the territory of Russia. Iran is located on southern shores sea, it owns 15% of the entire coastline. The eastern coastline is shared by Kazakhstan and Turkmenistan. Azerbaijan is located in the southwestern territories of the Caspian region.

The issue of dividing the lake’s waters between the Caspian states has been the most pressing for many years. The heads of five states are trying to find a solution that would satisfy everyone's needs and requirements.

Natural resources of the lake

Caspian Sea since ancient times for local residents served as a water transport route.

The lake is famous for valuable fish species, in particular sturgeon. Their reserves account for up to 80% of the world's resources. The issue of preserving the sturgeon population is of international importance; it is being resolved at the level of the government of the Caspian states.

The Caspian seal is another mystery of the unique sea-lake. Scientists have still not fully unraveled the mystery of the appearance of this animal in the waters of the Caspian Sea, as well as other species of animals of northern latitudes.

In total, the Caspian Sea is home to 1,809 species of different groups of animals. There are 728 species of plants. Most of them are “indigenous inhabitants” of the lake. But there is a small group of plants that were brought here intentionally by humans.

Of the mineral resources, the main wealth of the Caspian Sea is oil and gas. Some information sources compare the oil reserves of the Caspian Lake fields with those of Kuwait. Industrial sea mining of black gold is carried out on the lake with late XIX century. The first well appeared on the Absheron shelf in 1820.

Today, governments unanimously believe that the region cannot be viewed only as a source of oil and gas, while ignoring the ecology of the Caspian Sea.

Except oil fields, in the Caspian region there are deposits of salt, stone, limestone, clay and sand. Their production also could not but affect the ecological situation of the region.

Sea level fluctuations

The water level in the Caspian Lake is not constant. This is evidenced by evidence dating back to the 4th century BC. The ancient Greeks, who explored the sea, discovered big bay at the confluence of the Volga. The existence of a shallow strait between the Caspian and the Sea of Azov was also discovered by them.

There are other data on the water level in the Caspian Lake. The facts suggest that the level was much lower than what exists now. The ancients are proof architectural structures, discovered on the seabed. The buildings date back to the 7th-13th centuries. Now the depth of their flooding ranges from 2 to 7 meters.

In 1930, the water level in the lake began to decline catastrophically. The process continued for almost fifty years. This caused great concern among people, since all economic activity in the Caspian region is adapted to the previously established water level.

From 1978 the level began to rise again. Today he has become more than 2 meters higher. This is also an undesirable phenomenon for people living on the coast of the lake-sea.

The main reason affecting fluctuations in the lake is climate change. This entails an increase in the volume of river water entering the Caspian Sea, the amount of precipitation, and a decrease in the intensity of water evaporation.

However, it cannot be said that this is the only opinion that explains the fluctuation in water level in the Caspian Lake. There are others, no less plausible.

Human activities and environmental issues

The area of the Caspian Lake's drainage basin is 10 times larger than the surface of the reservoir itself. Therefore, all changes occurring in such a vast territory in one way or another affect the ecology of the Caspian Sea.

Human activity plays an important role in changing the environmental situation in the Caspian Lake region. For example, pollution of a reservoir with harmful and dangerous substances occurs along with the influx of fresh water. This is directly related to industrial production, mining and other economic activity people in the drainage basin.

The state of the environment of the Caspian Sea and adjacent territories is of general concern to the governments of the countries located here. Therefore, discussion of measures aimed at preserving unique lake, its flora and fauna, has become traditional.

Each state has an understanding that only through joint efforts can the ecology of the Caspian Sea be improved.

The coastline of the Caspian Sea is estimated at approximately 6,500 - 6,700 kilometers, with islands - up to 7,000 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 water streams and the 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.

Peninsulas of the Caspian Sea

Large peninsulas of the Caspian Sea:
* Agrakhan Peninsula
* 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
* Tub-Karagan

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

Most large islands:

* Ashur-Ada
* Garasu
*Hum
* Dash
* Zira (island)
* Zyanbil
* Cure Dasha
* Khara-Zira
* Sengi-Mugan
* Chechen (island)
* Chygyl

Large bays of the Caspian Sea:

* Agrakhan Bay,
* Komsomolets (bay),
* Mangyshlak,
* Kazakh (bay),
* Turkmenbashi (bay) (formerly Krasnovodsk),
* Turkmen (bay),
* Gizilagach,
* Astrakhan (bay)
* Gyzlar
* Hyrcanus (formerly Astarabad) and
* Anzeli (formerly Pahlavi).

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 (Russia), Ural, Emba (Kazakhstan), Kura (Azerbaijan), Samur (Russian border with Azerbaijan), Atrek (Turkmenistan) and others. Largest river, flowing into the Caspian Sea - the Volga, its average annual flow is 215-224 cubic kilometers. The Volga, Ural, Terek and Emba provide up to 88 - 90% of the annual runoff of the Caspian Sea.

Basin of the Caspian Sea

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

Coastal states

The Caspian Sea washes the shores of five coastal states:
* Russia (Dagestan, Kalmykia and Astrakhan region) - in the trap and north-west, the length of the coastline is 695 kilometers
* Kazakhstan - in the north, northeast and east, coastline length 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, coastline length 955 kilometers

Cities on the Caspian Sea coast

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

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

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

Area, depth, volume of water

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

Water level fluctuations

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

Water temperature

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 eastern sea, and in the open sea the water temperature is 2-4 °C higher than near the coasts. Based on the nature of the horizontal structure of the temperature field in the annual cycle of variability, three time periods can be distinguished in the upper 2-meter layer. From October to March, the water temperature increases in the southern and eastern regions, which is especially clearly visible in the Middle Caspian. Two stable quasi-latitudinal zones can be distinguished, where temperature gradients are increased. This is, firstly, the border between the Northern and Middle Caspian, and, secondly, between the Middle and Southern. At the ice edge, in the northern frontal zone, the temperature in February-March increases from 0 to 5 °C, in the southern frontal zone, in the area of the Absheron threshold, from 7 to 10 °C. During this period, the least cooled waters are in the center of the South Caspian Sea, which form a quasi-stationary core.

In April-May, the area of minimum temperatures moves to the Middle Caspian Sea, which is associated with faster heating of waters in the shallow northern part of the sea. True, at the beginning of the season in the northern part of the sea a large amount of heat is spent on melting ice, but already in May the temperature here rises to 16-17 °C. In the middle part the temperature at this time is 13-15 °C, and in the south it increases to 17-18 °C.

Spring warming of water evens out horizontal gradients, and the temperature difference between coastal areas and open sea does not exceed 0.5 °C. Warming up of the surface layer, starting in March, disrupts the homogeneity in the temperature distribution with depth. In June-September, horizontal homogeneity in the temperature distribution in the surface layer is observed. In August, which is the month of greatest warming, the water temperature throughout the sea is 24-26 °C, and in the southern regions it rises to 28 °C. In August, the water temperature in shallow bays, for example, in Krasnovodsk, can reach 32 °C. The main feature of the water temperature field at this time is upwelling. It is observed annually along the entire eastern coast of the Middle Caspian and partially penetrates even into the Southern Caspian.

The rise of cold deep waters occurs with varying intensity as a result of the influence of northwest winds prevailing in the summer season. The wind in this direction causes the outflow of warm surface waters from the coast and the rise of colder waters from the intermediate layers. Upwelling begins in June, but it reaches its greatest intensity in July-August. As a result, a decrease in temperature is observed on the surface of the water (7-15 °C). Horizontal temperature gradients reach 2.3 °C at the surface and 4.2 °C at a depth of 20 m.

The source of upwelling gradually shifts from 41-42° north. latitude in June, to 43-45° north. latitude in September. Summer upwelling is of great importance for the Caspian Sea, radically changing the dynamic processes in the deep-water area. In open areas of the sea, in late May - early June, the formation of a temperature jump layer begins, which is most clearly expressed in August. Most often it is located between horizons of 20 and 30 m in the middle part of the sea and 30 and 40 m in the southern part. Vertical temperature gradients in the shock layer are very significant and can reach several degrees per meter. In the middle part of the sea, due to the surge off the eastern coast, the shock layer rises close to the surface.

Since in the Caspian Sea there is no stable baroclinic layer with a large reserve of potential energy similar to the main thermocline of the World Ocean, then with the cessation of the prevailing winds causing upwelling and with the beginning of autumn-winter convection in October-November, a rapid restructuring of temperature fields to the winter regime occurs. In the open sea, the water temperature in the surface layer drops in the middle part to 12-13 °C, in the southern part to 16-17 °C. In the vertical structure, the shock layer is eroded due to convective mixing and disappears by the end of November.

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. The salinity of water changes especially sharply in the northern part of the sea: from 0.1 units. psu in the estuary areas of the Volga and Ural up to 10-11 units. psu on the border with the Middle Caspian.

Mineralization in shallow salty bays-kultuks can reach 60-100 g/kg. In the Northern Caspian, during the entire ice-free period from April to November, a salinity front of a quasi-latitudinal location is observed. The greatest desalination, associated with the spread of river flow across the sea, is observed in June. On the formation of the salinity field in the Northern Caspian Sea big influence exerts a wind field. In the middle and southern parts sea salinity fluctuations are small. Basically it is 11.2-12.8 units. psu, increasing in the southern and eastern directions. With depth, salinity increases slightly (by 0.1-0.2 units psu).

In the deep-sea part of the Caspian Sea, in the vertical profile of salinity, characteristic deflections of isohalines and local extrema are observed in the area of the eastern continental slope, which indicate the processes of bottom sliding of waters salinizing in the eastern shallow waters of the South Caspian. The magnitude of salinity also strongly depends on sea level and (which is interconnected) on the volume of continental runoff.

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

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 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.

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

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

Currents

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

Animal world

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

Vegetable world

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

Origin of the Caspian Sea

The Caspian Sea is of oceanic origin - its bed is composed of oceanic-type crust. It was formed approximately 10 million years ago, when the closed Sarmatian Sea, which lost contact with the world's oceans approximately 70 million years ago, was divided into two parts - the "Caspian Sea" and the Black Sea.

Anthropological and cultural history Caspian Sea

Finds in the Khuto u cave south coast The Caspian Sea indicates that man lived in these areas approximately 75 thousand years ago. The first mentions of the Caspian Sea and the tribes living on its coast are found in Herodotus. Around the V-II centuries. BC e. Saka tribes lived on the Caspian coast. Later, during the period of settlement of the Turks, in the period of the IV-V centuries. n. e. Talysh tribes (Talysh) lived here. According to ancient Armenian and Iranian manuscripts, Russians sailed the Caspian Sea from the 9th - 10th centuries.

Research of the Caspian Sea

Research of the Caspian Sea was started by Peter the Great, when, on his order, an expedition was organized in 1714-1715 under the leadership of A. Bekovich-Cherkassky. In the 1820s, hydrographic research was continued by I. F. Soyomov, and later by I. V. Tokmachev, M. I. Voinovich and other researchers. At the beginning of the 19th century, instrumental surveys of the shores were carried out by I. F. Kolodkin, in the mid-19th century. - instrumental geographical survey under the direction of N. A. Ivashintsev. Since 1866, for more than 50 years, expeditionary research on the hydrology and hydrobiology of the Caspian Sea was carried out under the leadership of N. M. Knipovich. In 1897, the Astrakhan Research Station was founded. In the first decades of Soviet power, geological research by I.M. Gubkin and other Soviet geologists was actively carried out in the Caspian Sea, mainly aimed at searching for oil, as well as research into the study of water balance and level fluctuations in 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. 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.

Shipping

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

Fishing and seafood production

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

Recreational resources

Natural environment of the Caspian coast with sandy beaches, mineral waters And therapeutic mud in the coastal zone creates good conditions for rest and treatment. At the same time, in terms of the degree of development of resorts and the tourism industry, the Caspian coast noticeably loses Black Sea coast Caucasus. At the same time, in last years The tourism industry is actively developing on the coasts of Azerbaijan, Iran, Turkmenistan and Russian Dagestan.

Ecological problems

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

Border dispute over the status of the Caspian Sea

After the collapse of the USSR, the division of the Caspian Sea has long been and still remains the subject of unresolved disagreements related to the division of Caspian shelf resources - oil and gas, as well as biological resources. For a long time, negotiations were ongoing between the Caspian states on the status of the Caspian Sea - Azerbaijan, Kazakhstan and Turkmenistan insisted on dividing the Caspian along the median line, Iran insisted on dividing the Caspian by one-fifth between all Caspian states. In 2003, Russia, Azerbaijan and Kazakhstan signed an agreement on the partial division of the Caspian Sea along the median line.

Coordinates: 42.622596 50.041848

, Kazakhstan, Turkmenistan, Iran, Azerbaijan

Geographical position

Caspian Sea - view from space.

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 - Northern Caspian, Middle Caspian and 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.

Coast of the Caspian Sea

Coast of the Caspian Sea in Turkmenistan

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

Peninsulas of the Caspian Sea

Ashur-Ada
Garasu
Zyanbil
Khara-Zira
Sengi-Mugan
Chygyl

Bays of the Caspian Sea

Russia (Dagestan, Kalmykia and Astrakhan region) - in the west and northwest, the length of the coastline is about 1930 kilometers
Kazakhstan - in the north, northeast and east, the length of the coastline is about 2320 kilometers
Turkmenistan - in the southeast, the length of the coastline is about 650 kilometers
Iran - in the south, the length of the coastline is about 1000 kilometers
Azerbaijan - in the southwest, the length of the coastline is about 800 kilometers

Cities on the Caspian Sea coast

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

Physiography

Area, depth, volume of water

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

Water level fluctuations

Vegetable world

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

History of the Caspian Sea

Origin of the Caspian Sea

Anthropological and cultural history of the Caspian Sea

Finds in the Khuto Cave off the southern coast of the Caspian Sea indicate that man lived in these areas approximately 75 thousand years ago. The first mentions of the Caspian Sea and the tribes living on its coast are found in Herodotus. Around the V-II centuries. BC e. Saka tribes lived on the Caspian coast. Later, during the period of settlement of the Turks, in the period of the 4th-5th centuries. n. e. Talysh tribes (Talysh) lived here. According to ancient Armenian and Iranian manuscripts, Russians sailed the Caspian Sea from the 9th-10th centuries.

Research of the Caspian Sea

Research of the Caspian Sea was started by Peter the Great, when, on his order, an expedition was organized in 1714-1715 under the leadership of A. Bekovich-Cherkassky. In the 1720s, hydrographic research was continued by the expedition of Karl von Werden and F. I. Soimonov, and later by I. V. Tokmachev, M. I. Voinovich and other researchers. At the beginning of the 19th century, instrumental surveys of the shores were carried out by I. F. Kolodkin, in the mid-19th century. - instrumental geographical survey under the direction of N. A. Ivashintsev. Since 1866, for more than 50 years, expeditionary research on the hydrology and hydrobiology of the Caspian Sea was carried out under the leadership of N. M. Knipovich. In 1897, the Astrakhan Research Station was founded. In the first decades of Soviet power, geological research by I.M. Gubkin and other Soviet geologists was actively carried out in the Caspian Sea, mainly aimed at searching for oil, as well as research into the study of water balance and level fluctuations in the Caspian Sea.

Economy of the Caspian Sea

Mining of oil and gas

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.

Shipping

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

Fishing and seafood production

Recreational resources

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

Ecological problems

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

International status of the Caspian Sea

Legal status of the Caspian Sea

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

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

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

Delineation of sections of the Caspian seabed for subsoil use

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

, Kazakhstan, Turkmenistan, Iran, Azerbaijan

Geographical position

Caspian Sea - view from space.

Coast of the Caspian Sea

Coast of the Caspian Sea in Turkmenistan

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

Peninsulas of the Caspian Sea

Ashur-Ada
Garasu
Zyanbil
Khara-Zira
Sengi-Mugan
Chygyl

Bays of the Caspian Sea

Russia (Dagestan, Kalmykia and Astrakhan region) - in the west and northwest, the length of the coastline is about 1930 kilometers
Kazakhstan - in the north, northeast and east, the length of the coastline is about 2320 kilometers
Turkmenistan - in the southeast, the length of the coastline is about 650 kilometers
Iran - in the south, the length of the coastline is about 1000 kilometers
Azerbaijan - in the southwest, the length of the coastline is about 800 kilometers

Cities on the Caspian Sea coast

Physiography

Area, depth, volume of water

Water level fluctuations

Vegetable world

History of the Caspian Sea

Origin of the Caspian Sea

Anthropological and cultural history of the Caspian Sea

Research of the Caspian Sea

Economy of the Caspian Sea

Mining of oil and gas

Shipping

Fishing and seafood production

Recreational resources

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

Ecological problems

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

International status of the Caspian Sea

Legal status of the Caspian Sea

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

Delineation of sections of the Caspian seabed for subsoil use

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

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