Large islands of the Caspian Sea. Caspian Sea

The Caspian Sea is located on the border of Europe and Asia and is surrounded by the territories of five states: Russia, Azerbaijan, Iran, Turkmenistan and Kazakhstan. Despite its name, the Caspian Sea is the largest lake on the planet (its area is 371,000 km2), but the bottom, composed of oceanic crust, and salty water, together with its large size, give reason to consider it a sea. A large number of rivers flow into the Caspian Sea, for example, such large ones as the Volga, Terek, Ural, Kura and others.

Relief and depth of the Caspian Sea

Based on the bottom topography, the Caspian Sea is divided into three parts: southern (the largest and deepest), middle and northern.

In the northern part, the depth of the sea is the smallest: on average it ranges from four to eight meters, and the maximum depth here reaches 25 m. The northern part of the Caspian Sea is limited by the Mangyshlak Peninsula and occupies 25% of the total area of the reservoir.

The middle part of the Caspian Sea is deeper. Here the average depth becomes 190 m, while the maximum is 788 meters. The area of the middle Caspian Sea is 36% of the total, and the volume of water is 33% of the total volume of the sea. It is separated from the southern part by the Absheron Peninsula in Azerbaijan.

The deepest and largest part of the Caspian Sea is the southern one. It occupies 39% of the total area, and its share of the total water volume is 66%. Here is the South Caspian depression, which contains the deepest point of the sea - 1025 m.

Islands, peninsulas and bays of the Caspian Sea

There are about 50 islands in the Caspian Sea, almost all of them are uninhabited. Due to the shallower depth of the northern part of the sea, most of the islands are located there, among them the Baku archipelago belonging to Azerbaijan, the Tyuleni Islands in Kazakhstan, as well as many Russian islands off the coast of the Astrakhan region and Dagestan.

Among the Caspian Sea peninsulas, the largest are Mangyshlak (Mangistau) in Kazakhstan and Absheron in Azerbaijan, on which such large cities as the capital of the country Baku and Sumgayit are located.

Kara-Bogaz-Gol Bay Caspian Sea

The coastline of the sea is very indented, and there are many bays on it, for example, Kizlyarsky, Mangyshlaksky, Dead Kultuk and others. The Kara-Bogaz-Gol Bay deserves special mention, which is actually a separate lake connected to the Caspian Sea by a narrow strait, thanks to which it maintains a separate ecosystem and higher salinity of water.

Fishing in the Caspian Sea

Since ancient times, the Caspian Sea has attracted residents of its shores with its fish resources. About 90% of the world's sturgeon production is caught here, as well as fish such as carp, bream, and sprat.

Caspian Sea video

In addition to fish, the Caspian Sea is extremely rich in oil and gas, the total reserves of which are about 18-20 million tons. Salt, limestone, sand and clay are also mined here.

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The islands of the Caspian Sea are located in the North Caucasus Federal District of the Russian Federation, it was formed by the Decree of the President of Russia on January 19, 2010.

The center of the district is the city of Pyatigorsk. It includes six republics: Dagestan; Ingushetia; Karachay-Cherkessia; Kabardino-Balkarian; North Ossetia; Chechen. And also the Stavropol region with its center in the city of Stavropol. The water border of the district lies in the Republic of Dagestan, it has access to the Caspian Sea, in which the islands of the Caspian Sea are located.

The coast of Dagestan is poorly dissected, there are few bays and dry lands. The most famous among the islands of the Caspian Sea is the Chechen archipelago, located north of the Agrakhan Peninsula, on the northeastern coast. It consists of a group of small sandy islands, which change their shape depending on the water level in the Caspian Sea.

Another of the Caspian Sea islands, Chechen, is located in the northwestern part of the coast and is part of the Chechen archipelago. This is one of the largest landmass. Administratively it belongs to the Kirovsky district of Makhachkala. A settlement with the same name is located here. Since 1965, there has been a testing base for Ekranoplans. The remaining islands from the group of islands of the Caspian Sea are small: Bazar, Pichuhonok, Yaichny, Prygunki.

The Tyuleniy land plot from the group of islands of the Caspian Sea is located thirty kilometers from the coastline of Cape Suyutkina Spit. It got its name from the Caspian seal fishery in these places. Until the 50s of the last century, there was a fishing village here, but now there are no permanent residents.

Where Europe meets Asia, there is one of the unique bodies of water, which is officially called a sea, and unofficially called a lake - the Caspian Sea, which washes the shores of several countries with its waters. , or rather, its northeastern part, overlooks the Caspian coast. What mysteries does the Caspian Sea hold, how big a role does it play in the life of the country, and how can people benefit the sea itself?

Geography of the Caspian Sea

Researchers are still arguing about what the Caspian Sea really is – a lake or a sea. The fact is that this reservoir is the largest of all drainless ones. These are those that have no connection with the World Ocean.

All rivers of the Caspian Sea originate on land, but do not reach the ocean shores. Thus, it is closed and can well be called a lake. However, the Caspian Sea is quite large, and its bottom is the earth’s crust, which is of the oceanic type. This indicates that the sea appeared here millions of years ago.

The fact that once upon a time on the planet, or rather, on the territory where Europe and Asia are located today, a huge prehistoric Sarmatian Sea splashed - this is the name scientists gave it. This was 12 million years ago. Water covered the entire area of the current landmass.

The Caucasus and Crimea were islands in this incredibly large sea. However, it gradually desalinated and dried out due to the slow rise of land. As a result, in place of the Sarmatian Sea, peculiar “puddles” were formed - the Caspian, Black, Aral, and Azov seas.

Finding the Caspian Sea on a geographical map today is quite simple. It is located in the region of Asia Minor and is separated from the Black Sea by the Caucasus, which acts as a kind of isthmus between these two bodies of water. It has outlines elongated from north to south. Its coordinates are 36°34"–47°13" north latitude and 46°–56° east longitude. Modern borders are the coasts of five states:

Russia.
Azerbaijan.
Turkmenistan.
Kazakhstan.
Iran.

Geographers divide the sea's territory into the Northern, Middle and Southern Caspian, with the southern part occupying about 40% of the area, and the northern part making up only 25%. There are also boundaries to these divisions. Thus, the Middle Caspian is separated from the North by a conventional line drawn from Cape Tyub-Karagan to the island of Chechen. And the border between South and Middle runs along Cape Gan-Gulu and Chilov Island.

Area and depth

Many people are interested in the area of the Caspian Sea, but these parameters change periodically. It all depends on seasonal variations in depth. So, if the water level in the sea is about 27 meters, the reservoir can reach over 370 thousand square kilometers. During these periods, it becomes full-flowing, and holds almost 45% of the total volume of fresh lake water on the planet.

The Caspian Sea is heterogeneous in depth parameters. Thus, the shallowest part is the northern one, its average depth does not exceed 4 meters, and the maximum is 25 meters. The southern part is the deepest, in the area of the South Caspian depression it is 1025 meters. Overall, the researchers found that the average depth of the reservoir is 208 meters according to the bathygraphic curve.

The Caspian Lake is third in depth after lakes Baikal and Tanganyika. As for sea level, it fluctuates significantly. Scientific measurements of the reservoir began in 1837. Scientists, based on historical documents and archaeological research, claim that the highest water level was observed at the turn of the 13th-14th centuries, then it began to decline.

Over the course of three thousand years of our civilization, the water level in the Caspian Sea has changed by 15 meters. The reasons can be very different. First of all, these are geological changes in the state of the earth's crust, as well as climate fluctuations in a given region and human actions.

Temperature and climate

Since today the Caspian basin is home to not only industrial enterprises, but also resorts, the temperature of the Caspian Sea is of keen interest to many. This indicator is also subject to seasonal changes, and they are quite significant.

In winter, the difference in temperature fluctuations is within 10 degrees. In the southern part of the reservoir, the water temperature in winter has an average temperature of 11 degrees, while in the northern part of the sea this temperature is no more than 0.5 degrees, and sometimes even slight glaciation is observed. The northern regions, as the shallowest waters, warm up faster in summer and can reach temperatures of up to 26 degrees. At the same time, the water temperature in the western part of the reservoir is permanently higher than in the eastern part.

The summer period, lasting from June to September, makes temperature indicators more uniform throughout the sea. At this time, in the upper layers the water warms up to 26 degrees, and in the southern part it can increase to 28 degrees. By the velvet season in shallow areas, the water can warm up even more and reach 32 degrees.

In addition, in summer there is a phenomenon such as the rise of deep water layers to the surface. This is the so-called upwelling, but scientists do not observe it throughout the entire water area, but mainly only in the east; sometimes deep waters rise in the southern part of the reservoir. As a result, the water temperature on average can be understood by 10 degrees.

Like other marine bodies of water, the water in the Caspian Sea is salty. However, the level of salt saturation may vary depending on individual areas. The salt concentration is highest in the western and southern parts of the reservoir. In the northern regions, sea water is constantly diluted with fresh water from rivers. However, throughout the sea, salt concentrations vary depending on the season of the year.

In addition, winds are the reason why water becomes saltier or fresher. For example, in the Southern and Middle Caspian these fluctuations are weakly expressed, in contrast to the Northern.

The climate of this maritime region also varies. The southern part of the sea has a subtropical climate, the middle part has a temperate climate, and the northern part has a continental climate. As a result, the air temperature on the coast varies.

It is worth noting that it is hottest in the south and southeast of the reservoir. Here the temperature can sometimes reach 44 degrees in summer, and the average temperature is 26-27 degrees. The north of the reservoir also cannot complain about the cold in summer - air temperatures up to 25 degrees are recorded here. As for winter, the air temperature in the north can reach -10 degrees, and in the south – up to +10 degrees.

Pool Features

There is no need to assume that the Caspian Sea is just a closed body of water limited by its shores. On the map, the sea has fairly smooth shores, but in reality its borders are indented by small capes and peninsulas, as well as channels and river mouths. The coastline is about 7 thousand kilometers (if you take into account the islands).

The coast of the lake in its northern part looks low, there is some swampiness due to the presence of many channels. From the east, the Caspian coast is mainly limestone, and the territories smoothly turn into semi-desert lands. The tortuosity of the coastal edges is highest in the east and west.

Any large body of water cannot do without islands, and the Caspian Sea is no exception. The islands of the Caspian Sea are diverse, their total number is almost 50 islands of different sizes. The largest include:

Boyuk-Zira;
seal;
Chechen;
Ashur-Ada;
Ogurchinsky;
Cure-Dashi;

The coast of the Caspian Sea is also rich in peninsulas, among which Mangyshlak, Apsheronsky, and Tyub-Karagan stand out. Finally, the geography of the Caspian Sea includes many large and small bays. The most famous of them are:

Kizlyarsky;
Kara-Bogaz-Gol;
Mangyshlaksky;
Gizilagac;
Turkmenbashi;
Astrakhan (Astrakhansky);
Hyrcanus.

Of these bays, one can especially highlight Kara-Bogaz-Gol, which is located in the eastern part of the sea and today belongs to Turkmenistan. Until the end of the twentieth century, it was a kind of Caspian lagoon, which was connected to the “big water” by the strait. In the 1980s, back during the Soviet era, a dam and then a dam were built here, as a result of which the water level in the bay was reduced.

Today the situation has returned to its original point, since the strait was restored. Water enters the bay in volumes of 10-17 cubic kilometers annually. However, due to the hot climate, it evaporates, so the Kara-Bogaz-Gol Bay is extremely salty.

The Caspian Sea, like other similar bodies of water, has rich flora and fauna. A variety of algae predominate here, and researchers believe that most of the Caspian is of local origin. However, it is also possible that some algae were brought here artificially - for example, on the bottoms of merchant ships from other seas.

The Caspian Sea is quite diverse. There are more than 100 species of fish. This is where the famous sturgeon and other fish of the same family are found. Basically, the fish of the Caspian are those that live in fresh or low-salt waters: pike, carp, salmon, mullet, perch, carp, some of which are listed in. You can find seals in the sea.

Development of waters and seabed

Who among us does not remember the famous phrase from geography textbooks: “The Volga flows into the Caspian Sea.” This river is the largest of those whose mouth is the Caspian Sea. Every year it delivers up to 224 cubic kilometers of fresh water to the sea. But there are others, smaller ones, who also flock here. In addition to Volga, these are:

Terek.
Ural.
Samur.
Sulak.

These rivers flow through the territory of Russia, and in addition to them, the waters of the Atrek (Turkmenistan), Kura (), Sefidrud (Iran), and Emba (Kazakhstan) rivers flow into the Caspian Sea. In total, out of 130 different rivers flowing into the Caspian Sea, the mouths of nine water streams are formed in the form of a delta.

The development of the lake took place over many centuries. Today, the ports of the Caspian Sea connect the shores of the reservoir with trade routes. Of the Russian ports, the most important are Makhachkala and Astrakhan, from which ships are constantly sent to the Kazakh Aktau, the Azerbaijani Baku and other coastal shores of the Caspian Sea. In addition, it is connected to the Sea of Azov, which is reached through the Don and Volga rivers, as well as through the Volga-Don Canal.

An important direction in the economic development of the Caspian basin and the sea itself is oil production. The oil resources of the sea currently amount to approximately 10 billion tons - these are the estimates given by researchers. If we add gas condensate to this, then the reserves double.

Oil production is the most important sector of the economy of the countries of the Caspian region, therefore, for many years, disagreements regarding the use of the resources of the sea have been unresolved. During the existence of the USSR, the territory of the Caspian Sea belonged to the Soviet Union and Iran.

Legal documents on the division of the reservoir and the use of its shelf, which were concluded between Iran and the USSR, are still in force. At the same time, disputes regarding the legal division of territories continue. Thus, Iran proposes to divide it equally between five countries, and three former Soviet republics insist that the reservoir be divided along the median line of demarcation.

This issue remains very serious, because depending on where the sea should be divided, not only the volume of oil production for each Caspian state depends, but also the use of other resources of the reservoir. Here we can talk, first of all, about fisheries, because the sea is very generous with fish stocks.

They harvest not only fish, but also the famous caviar, as well as seal. However, the reproduction of the fish stock today would be much more effective if it were not for the poachers of the Caspian Sea, who organize illegal sturgeon fishing and illegally extract caviar.

Moreover, they exist in almost all Caspian countries, so the fight against them is common to the neighboring countries of the Caspian basin. As a result, sturgeon exports have been limited in recent years, as both Russia and other Caspian countries are interested in preserving this natural wealth of the region.

Poaching is a serious problem, and today Russia, together with Azerbaijan, Iran, Kazakhstan and Turkmenistan, are developing measures aimed at legally limiting illegal fishing.

However, there is another big problem of the Caspian Sea - pollution of sea waters. The reason is oil production, as well as oil transportation by sea. We should not forget that large cities located on the shores of a reservoir are a constant source of water pollution. In addition, industrial enterprises, despite strict prohibitions, sometimes still discharge waste into rivers, which then end up in the sea.

Environmental violations lead not only to general pollution of the Caspian waters, but also to changes in the boundaries of the reservoir itself (swamping, drying out, and so on). But it’s not even worth talking about the importance of the Caspian Sea for the entire region.

Holidays at the resorts of the Caspian Sea

In order to understand what human civilization can lose by losing the Caspian Sea, you can look at its photo. This body of water is an amazing place for a good rest, and the sea landscapes invariably impress everyone who comes here. A vacation spent on the Caspian Sea turns out to be no worse than on the Black Sea shores. Fresh air, mild climate and well-maintained beaches - this is what it can give to tourists.

If you decide to go to the Caspian Sea, the prices for holidays will pleasantly surprise you. Tourism is valued largely because it turns out to be inexpensive compared to what awaits tourists going to resorts in other regions of the planet. Residents of Russia can relax very cheaply within their country and at the same time receive excellent service, no different in level from the Mediterranean.

There are several resorts in Russian cities (most of which are in), which are particularly popular with tourists. This:

Astrakhan;
Dagestan Lights;
Kaspiysk;
Izberbash;
Lagan.

If tourists go to Derbent, first of all, to see its ancient sights, and to Astrakhan - to enjoy fishing, then vacation spots in Makhachkala are among the most comfortable and cozy beaches of the Caspian Sea.

This resort attracts not only a comfortable holiday, but also the opportunity to improve your health, because there are thermal and mineral springs here. Among the foreign resorts, we can note the Kazakh Aktau, the Azerbaijani Sumgait and the Turkmen recreation area Avaza.

Today the Caspian Sea is one of the world's most important regions economically. Without it, it is impossible to imagine modern Eurasia and, especially, the history of Russia. This means that the state of this reservoir must be protected by the state.

Hyrcanian Sea;
Khvalynskoe Sea or Khvalis Sea- Old Russian name, derived from the name of the inhabitants of Khorezm who traded in the Caspian Sea - hvalis;
Tabasaran Sea
Khazar Sea- name in Arabic ( Bahr al-Khazar), Persian ( Daria-e Khazar), Turkish and Azerbaijani ( Khazar Denizi) languages;
Abeskun Sea;
Sarayskoye Sea;
Derbent Sea;
Xihai

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

Peninsulas of the Caspian Sea

Large peninsulas of the Caspian Sea:

The Absheron Peninsula, located on the western coast of the Caspian Sea in the territory of Azerbaijan, at the northeastern end of the Greater Caucasus, on its territory there are cities and Sumgayit
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

Islands of the Caspian Sea

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

Largest islands:

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

Bays of the Caspian Sea

Large bays of the Caspian Sea:

Agrakhan Bay
Kizlyar Bay
Dead Kultuk (bay) (former Komsomolets, former Tsesarevich Bay)
Kaydak
Mangyshlak Bay
Kazakh (bay)
Turkmenbashi (bay) (formerly Krasnovodsk)
Turkmen (bay)
Gizilagac
Astrakhan (bay)
Hasan-kuli
Gizlar
Hyrcanus (formerly Astarabad)
Anzeli (formerly Pahlavi)

Kara-Bogaz-Gol

in September 1995]]Near the eastern coast there is a salt lake called Kara Bogaz Gol, which until 1980 was a bay-lagoon of the Caspian Sea, connected to it by a narrow strait. In 1980, a dam was built separating Kara-Bogaz-Gol from the Caspian Sea, and in 1984 a culvert was built, after which the level of Kara-Bogaz-Gol dropped by several meters. In 1992, the strait was restored, through which water flows from the Caspian Sea to Kara-Bogaz-Gol and evaporates there. Every year, 8-10 cubic kilometers of water (according to other sources - 25 cubic kilometers) and about 150 thousand tons of salt flow into Kara-Bogaz-Gol from the Caspian Sea.

Rivers flowing into the Caspian Sea

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

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 -,.

Coastal states

The Caspian Sea washes the shores of five coastal states:

(Dagestan, Kalmykia and Astrakhan region) - in the west and northwest, coastline length 695 kilometers
a - 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
a - in the south, coastline length - 724 kilometers
a - in the southwest, the length of the coastline is 955 kilometers

Cities on the Caspian Sea coast

The largest city - a port on the Caspian Sea - is 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 southeast of the Absheron Peninsula, there is an oil workers’ settlement called Neftyanye Kamni, whose structures are located on artificial islands, overpasses and technological sites.

Major Russian cities - the capital of Dagestan and the southernmost city of Russia - are located on the western coast of the Caspian Sea. It is also considered a port city of the Caspian Sea, which, however, is not located on the shores of the Caspian Sea, but in the Volga delta, 60 kilometers from the northern coast of the Caspian Sea.

On the eastern shore of the Caspian Sea there is a Kazakh port city, 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 coast, the largest of them is Anzeli.

Physiography

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 is approximately 392,600 square kilometers, the volume of water is 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 (1620 m) and (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 highest water level was recorded in 1882 (-25.2 m), the lowest in 1977 (-29.0 m) , since 1978 the water level has risen and in 1995 reached −26.7 m; since 1996, a downward trend has emerged again. Scientists associate the reasons for changes in the water level of the Caspian Sea with climatic, geological and anthropogenic factors.

Water temperature

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

In April-May, the area of minimum temperatures moves to the Middle Caspian Sea, which is associated with faster heating of waters in the shallow northern part of the sea. True, at the beginning of the season in the northern part of the sea a large amount of heat is spent on melting ice, but already in May the temperature here rises to 16 - 17 °C. In the middle part the temperature at this time is 13 - 15 °C, and in the south it increases to 17 - 18 °C. Spring warming of water evens out horizontal gradients, and the temperature difference between coastal areas and the open sea does not exceed 0.5 °C. Warming of the surface layer, which begins in March, disrupts the uniformity of temperature distribution with depth.

In June-September, horizontal uniformity in the temperature distribution in the surface layer is observed. In August, which is the month of greatest warming, the water temperature throughout the sea is 24 - 26 °C, and in the southern regions it rises to 28 °C. In August, the water temperature in shallow bays, for example, in Krasnovodsk, can reach 32 °C.

The main feature of the water temperature field at this time is upwelling. It is observed annually along the entire eastern coast of the Middle Caspian and partially penetrates even into the Southern Caspian. The rise of cold deep waters occurs with varying intensity as a result of the influence of 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 on the surface and 4.2 °C at a depth of 20 m. The source of upwelling gradually shifts from 41 - 42° N. in June to 43 - 45° N. in September. Summer upwelling is of great importance for the Caspian Sea, radically changing the dynamic processes in the deep-water area.

In open areas of the sea, at the end of May - beginning of June, the formation of a temperature jump layer begins, which is most clearly expressed in August. Most often it is located between horizons of 20 and 30 m in the middle part of the sea and 30 and 40 m in the southern part. Vertical temperature gradients in the shock layer are very significant and can reach several degrees per meter. In the middle part of the sea, due to the surge off the eastern coast, the shock layer rises close to the surface. Since in the Caspian Sea there is no stable baroclinic layer with a large reserve of potential energy similar to the main thermocline of the World Ocean, then with the cessation of the prevailing winds causing upwelling and with the beginning of autumn-winter convection in October-November, a rapid restructuring of temperature fields to the winter regime occurs. In the open sea, the water temperature in the surface layer drops in the middle part to 12 - 13 °C, in the southern part to 16 - 17 °C. In the vertical structure, the shock layer is eroded due to convective mixing and disappears by the end of November.

Water composition

The most conservative ions are potassium, sodium, chlorine and magnesium. The least conservative are calcium and bicarbonate ions. In the Caspian Sea, the content of calcium and magnesium cations is almost two times higher than in the Sea of Azov, and the sulfate anion is three times higher.

Water salinity changes especially sharply in the northern part of the sea: from 0.1 units. psu in the mouth areas of the Volga and Ural up to 10 - 11 units. psu on the border with the Middle Caspian. Mineralization in shallow salty bays-kultuks can reach 60 - 100 g/kg. In the Northern Caspian, during the entire ice-free period from April to November, a salinity front of a quasi-latitudinal location is observed. The greatest desalination, associated with the spread of river flow across the sea, is observed in June.

The formation of the salinity field in the Northern Caspian Sea is greatly influenced by the wind field. In the middle and southern parts of the sea, salinity fluctuations are small. Basically it is 11.2 - 12.8 units. psu, increasing in the southern and eastern directions. 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 - 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.

On the territory of the Caspian Sea, winds often blow, their average annual speed is 3-7 meters per second, and northern winds predominate in the wind rose. 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 and plant life

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, 819 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.

History of the Caspian Sea

Origin of the Caspian Sea

It 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 Black 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 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.

Economy of the Caspian Sea

Mining of oil and gas

Many oil and gas fields are being developed in the Caspian Sea. Proven oil resources in the Caspian Sea amount to 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

View from the Caspian Sea]] 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

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

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.

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

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 -,

Caspian Sea in the book: A. D. Dobrovolsky, B. S. Zalogin. Seas of the USSR. Publishing house Moscow. University, 1982.

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

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

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

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 by water streams and islands of the Volga and Ural deltas, the banks are low and swampy, and the water surface in many places is covered with thickets. The east coast is dominated by limestone shores adjacent to semi-deserts and deserts. The most winding shores are on the western coast in the area of the Absheron Peninsula and on the eastern coast in the area of the Kazakh Gulf and Kara-Bogaz-Gol.

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

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

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

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

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

The Caspian Sea washes the shores of five coastal states:

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

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

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

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

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

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

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

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

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

Large islands of the Caspian Sea. Caspian Sea

Relief and depth of the Caspian Sea

Islands, peninsulas and bays of the Caspian Sea

Kara-Bogaz-Gol Bay Caspian Sea

Fishing in the Caspian Sea

Caspian Sea video

Geography of the Caspian Sea

Area and depth

Temperature and climate

Pool Features

Development of waters and seabed

Holidays at the resorts of the Caspian Sea

Peninsulas of the Caspian Sea

Islands of the Caspian Sea

Bays of the Caspian Sea

Kara-Bogaz-Gol

Rivers flowing into the Caspian Sea

Basin of the Caspian Sea

Coastal states

Cities on the Caspian Sea coast

Physiography

Area, depth, volume of water

Water level fluctuations

Water temperature

Water composition

Bottom relief

Climate

Currents

Animal and plant life

Animal world

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

Ecological problems

International status of the Caspian Sea

Border dispute over the status of the Caspian Sea

see also