How many km is the Caspian Sea. Where does the Caspian Sea draw water from? Due to what Terek is replenished
The Caspian Lake is one of the most unique places on the ground. It keeps many secrets connected with the history of the development of our planet.
Position on the physical map
The Caspian is an internal drainless salt Lake. The geographical position of the Caspian Lake is the continent of Eurasia at the junction of parts of the world (Europe and Asia).
The length of the lakeshore line is 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 indented by the channels of the Volga and the Urals. 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.
East Coast The Caspian is adjacent to the lake. There are significant limestone deposits on the shores of the lake. The western and part of the eastern coast is characterized by a winding coastline.
The Caspian lake on the map is represented by a significant size. The entire territory adjacent to it was called the Caspian Sea.
Some characteristics
The Caspian Lake in terms of its area and the volume of water in it has no equal on Earth. 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 reservoirs, their area and volume of water, then the lake is commensurate with the Yellow, Baltic and Black Seas. By the same parameters, the Caspian surpasses the Tyrrhenian, Aegean, Adriatic and other seas.
The volume of water available in the Caspian Lake is 44% of the reserve of all lake waters of the planet.
Lake or sea?
Why is the Caspian lake called the sea? Is it really the impressive size of the reservoir that caused the assignment of such a “status”? More precisely, this was one of those reasons.
Others include a huge mass of water in the lake, the presence of a large wave during storm winds. All this is typical for real seas. It becomes clear why the Caspian Lake is called the sea.
But here one of the main conditions is not named, which must necessarily exist so that geographers can classify a reservoir as a sea. We are talking about the direct connection of the lake with the oceans. The Caspian does not meet this condition.
Where the Caspian Lake is located, a deepening in the earth's crust was formed 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. direct connection the waters of the lake and the ocean ceased to exist approximately 6 millennia ago. The conclusion from the above is that the Caspian Sea is a lake.
There is another feature that distinguishes the Caspian Sea from the sea - the salinity of the water in it 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 is she who “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 the sea. Now that many channels have been built by man, it has become a fact that the Volga connects the lake with the oceans.
The history of the lake
The modern appearance and geographical position of the Caspian Lake are due to continuous processes occurring on the surface of the Earth and in its depths. There were times when the Caspian was connected with the 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 the processes associated with the uplift and lowering of the earth's crust, mountains appeared on the site of the modern Caucasus. They isolated a body of water that was part of a vast ancient ocean. More than one 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 Kumo-Manych depression.
Periodically, the narrow strait was either drained or refilled with water. This was due to fluctuations in the level of the oceans and changes in the appearance of the land.
In a word, the origin of the Caspian Lake is closely connected with the general history of the formation of the Earth's surface.
The lake got its modern name because of the tribes of the Caspians, who inhabited the eastern parts of the Caucasus and the steppe zones of the Caspian territories. Over the entire history of its existence, the lake had 70 different names.
Territorial division of the lake-sea
The depth of the Caspian Lake in its different places is very different. Based on this, the entire water area of the lake-sea was conditionally divided into three parts: the Northern Caspian, the Middle and the Southern.
Shallow is Northern part lakes. Average depth of these places is 4.4 meters. The highest indicator is a mark of 27 meters. And on 20% of the entire area of the Northern Caspian, 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 part occupies 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, the climatic conditions on the coast of the lake are not the same. Seasonal changes in the territories 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 during 2-3 months of the year.
In summer, almost everywhere the Caspian Lake warms up to 25-30 degrees. warm water, excellent sandy beaches, sunny weather create excellent conditions for people to relax.
Caspian on the political map of the world
Five states are located on the shores of the Caspian Lake - Russia, Iran, Azerbaijan, Kazakhstan and Turkmenistan.
The territory of Russia includes the western regions of the Northern and Middle Caspian. Iran is located on the southern shores of the sea, it owns 15% of the entire length coastline. The eastern coastline is shared by Kazakhstan and Turkmenistan. Azerbaijan is located in the southwestern territories of the Caspian Sea.
The issue of dividing the water area of the lake between the Caspian states has been the most acute for many years. The heads of the five states are trying to find a solution that would satisfy the needs and requirements of everyone.
The natural wealth of the lake
Since ancient times, the Caspian has served as a waterway for local residents.
The lake is famous for its valuable species of fish, in particular sturgeon. Their reserves account for up to 80% of the world's resources. The issue of conservation of the sturgeon population has international importance, it is decided at the level of the government of the Caspian states.
The Caspian seal is another mystery of the unique sea-lake. Scientists have not yet 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, 1809 species live in the Caspian Sea various groups animals. There are 728 species of plants. Most of them are the "indigenous inhabitants" of the lake. But there is a small group of plants that were deliberately brought here by man.
Of the minerals, the main wealth of the Caspian is oil and gas. Some information sources compare the oil reserves of the Caspian Lake fields with Kuwait. Industrial marine mining of black gold has been carried out on the lake since the end of the 19th century. The first well appeared on the Apsheron shelf in 1820.
Today, the governments unanimously believe that the region cannot be considered only as a source of oil and gas, while leaving the Caspian ecology unattended.
In addition to oil fields, there are deposits of salt, stone, limestone, clay and sand on the territory of the Caspian Sea. Their production also could not but affect ecological situation region.
Sea level fluctuations
The water level in the Caspian Lake is not constant. This is evidenced by evidence relating to the IV century BC. The ancient Greeks, who explored the sea, discovered a large 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 show that the level was much lower than it is now. Ancient evidence is architectural structures found on seabed. The buildings date back to the 7th-13th centuries. Now the depth of their flooding is from 2 to 7 meters.
In 1930, the water level in the lake began to decline catastrophically. The process went on for almost fifty years. This caused great concern among people, since all the economic activities of the Caspian region are adapted to the previously established water level.
Since 1978 the level has started to rise again. Today it has become more than 2 meters taller. This is also an undesirable phenomenon for people living on the coast of the lake-sea.
Climate change is said to be the main reason for fluctuations in the lake. This entails an increase in the volume of river water entering the Caspian, 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 fluctuations in the water level in the Caspian Lake. There are others, no less plausible.
Human activities and environmental issues
The area of the catchment basin of the Caspian Lake is 10 times larger than the surface of the water area of the reservoir itself. Therefore, all the changes taking place 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 ecological situation in the area of the Caspian Lake. For example, pollution of a reservoir with harmful and hazardous substances occurs along with the influx of fresh water. It is directly related to industrial production, mining and other economic activity people in the watershed.
State environment The Caspian Sea and the territories adjacent to it are of general concern to the governments of the countries located here. Therefore, the 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.
November 29th, 2015
Is it correct to call the Caspian a sea?
It is known that the sea is part of the oceans. From this geographically correct point of view, the Caspian cannot be considered a sea, because it is separated from the ocean by huge land masses. Most short distance from the Caspian Sea to the Black Sea, the closest of the seas included in the system of the World Ocean, is 500 kilometers. Therefore, it would be more correct to speak of the Caspian as a lake. This is the world's largest lake, often referred to simply as the Caspian or lake-sea.
The Caspian has a number of features of the sea: its water is salty (however, there are other salt lakes), the area is not much inferior to the area of such seas as the Black, Baltic, Red, Northern, and even exceeds the area of \u200b\u200bAzov and some others (however, Canadian lake The upper one is also a huge area, like the three Seas of Azov). In the Caspian, fierce storm winds and huge waves are frequent (and this is not uncommon in Baikal).
So, after all, the Caspian Sea is a lake? That's Wikipedia says it Yes and big Soviet Encyclopedia replies that no one has yet been able to give a precise definition of this issue - "A generally accepted classification does not exist."
Do you know why this is very important and fundamental? And here's why...
The lake belongs to internal waters - the sovereign territories of coastal states, to which the international regime does not apply (the principle of non-intervention of the UN in the internal affairs of states). But the water area of the sea is divided differently, and the rights of coastal states are completely different here.
In my own way geographic location The Caspian itself, in contrast to the land territories surrounding it, has not been the object of any targeted attention on the part of the coastal states for many centuries. Only at the beginning of the XIX century. between Russia and Persia, the first treaties were concluded: Gulistan (1813) 4 and Turkmanchai (1828), summing up the results of the Russian-Persian war, as a result of which Russia annexed a number of Transcaucasian territories and received the exclusive right to keep a navy in the Caspian sea. Russian and Persian merchants were allowed to freely trade on the territory of both states and use the Caspian Sea to transport goods. The Turkmanchay Treaty confirmed all these provisions and became the basis for maintaining international relations between the parties until 1917.
After the October Revolution of 1917, in a note of the new Russian government that came to power on January 14, 1918, it renounced its exclusive military presence in the Caspian Sea. The agreement between the RSFSR and Persia of February 26, 1921 declared invalid all agreements concluded before it by the tsarist government. The Caspian Sea became a body of water for common use by the parties: both states were granted equal rights of free navigation, except in cases where the crews of Iranian ships could include citizens of third countries using the service for unfriendly purposes (Article 7). The 1921 agreement did not provide for a maritime border between the parties.
In August 1935, the following treaty was signed, the parties to which were new subjects of international law - the Soviet Union and Iran, which acted under the new name. The parties reaffirmed the provisions of the 1921 agreement, but introduced into the agreement a new concept for the Caspian - a 10-mile fishing zone, which limited the spatial limits for its participants to conduct this fishery. This was done in order to control and conserve the living resources of the reservoir.
In the context of the outbreak of World War II, unleashed by Germany, an urgent need arose to conclude a new treaty between the USSR and Iran on trade and navigation in the Caspian. The reason for this was the concern of the Soviet side, caused by Germany's interest in intensifying its trade relations with Iran and the danger of using the Caspian Sea as one of the stages of the transit route. The treaty signed between the USSR and Iran in 1940 10 protected the Caspian Sea from such a prospect: it repeated the main provisions of the previous agreements, which provided for the stay in its waters of ships of only these two Caspian states. It also included a provision for its indefinite validity.
The collapse of the Soviet Union radically changed the regional situation in the former Soviet space, in particular in the Caspian region. Among the large number of new problems, the problem of the Caspian Sea has also arisen. Instead of two states - the USSR and Iran, which previously bilaterally resolved all emerging issues of maritime navigation, fishing and the use of its other living and non-living resources, now there are five of them. Of the former, only Iran remained, Russia took the place of the USSR on the rights of succession, the remaining three are new states: Azerbaijan, Kazakhstan, Turkmenistan. They used to have access to the Caspian, but only as republics of the USSR, and not as independent states. Now, having become independent and sovereign, they have the opportunity to participate on an equal footing with Russia and Iran in the discussion and decision-making in the consideration of all the above issues. This was also reflected in the attitude of these states to the Caspian, since all five states that had access to it showed equal interest in the use of its living and non-living resources. And this is logical, and most importantly, justified: the Caspian Sea is rich in natural resources, both fish stocks and black gold - oil and blue fuel - gas. Exploration and production of the last two resources have long been the subject of the most heated and protracted negotiations. But not only them.
In addition to the presence of rich mineral resources, about 120 species and subspecies of fish live in the waters of the Caspian Sea, here is the world gene pool of sturgeons, the extraction of which, until recently, accounted for 90% of their total world catch.
Due to its location, the Caspian has traditionally and long been widely used for navigation, acting as a kind of transport artery between the peoples of the coastal states. On its shores there are such large seaports as the Russian Astrakhan, the capital of Azerbaijan Baku, the Turkmen Turkmenbashi, the Iranian Anzali and the Kazakh Aktau, between which trade, cargo and passenger sea transport routes have long been laid.
And yet, the main object of attention of the Caspian states is its mineral resources - oil and natural gas, to which each of them can lay claim within the boundaries that should be determined by them collectively on the basis of international law. And for this, they will have to divide between themselves both the Caspian Sea and its bottom, in the bowels of which its oil and gas are hidden, and develop rules for their extraction with minimal damage to a very fragile environment, primarily the marine environment and its living inhabitants.
The main obstacle in resolving the issue of the beginning of a wide extraction of the mineral resources of the Caspian Sea for the Caspian states continues to be its international legal status: should it be considered a sea or a lake? The complexity of the issue lies in the fact that these states themselves must solve it, and so far no agreement has been observed in their ranks. But at the same time, each of them seeks to start extracting Caspian oil and natural gas as soon as possible and make their sale abroad a permanent source of funds to form their budget.
Therefore, the oil companies of Azerbaijan, Kazakhstan and Turkmenistan, without waiting for the end of the settlement of existing disagreements on the territorial division of the Caspian Sea, have already begun active production of its oil, in the hope of ceasing to be dependent on Russia, turning their countries into oil producers and, in this capacity, begin to build their own long-term trading relations with neighbors.
However, the issue of the status of the Caspian Sea remains unresolved. Regardless of whether the Caspian states agree to consider it a “sea” or a “lake”, they will have to apply the principles corresponding to the choice made or develop their own in this case to the territorial division of its water area and bottom.
Kazakhstan was in favor of recognizing the Caspian as a sea. Such recognition will make it possible to apply to the division of the Caspian the provisions of the 1982 UN Convention on the Law of the Sea on Internal Waters, the Territorial Sea, the Exclusive Economic Zone, and the Continental Shelf. This would allow the coastal states to gain sovereignty over the subsoil of the territorial sea (Article 2) and exclusive rights to explore and develop the resources of the continental shelf (Article 77). But the Caspian cannot be called a sea from the position of the UN Convention on the Law of the Sea of 1982, since this body of water is closed and has no natural connection with the oceans.
In this case, the option of sharing its water area and bottom resources is also excluded.
In the treaties between the USSR and Iran, the Caspian Sea was considered as a border lake. With the legal status of a "lake" given to the Caspian Sea, it is supposed to be divided into sectors, as is done with respect to border lakes. But in international law there is no rule obliging states to do just that: division into sectors is an established practice.
The Russian Foreign Ministry has repeatedly made statements that the Caspian is a lake, and its waters and subsoil are the common property of the coastal states. Iran also considers the Caspian Sea as a lake from the position fixed in the treaties with the USSR. The country's government believes that this status implies the creation of a consortium for the unified management of production and use of its resources by the Caspian states. Some authors also share this opinion, for example, R. Mammadov believes that with such a status, the extraction of hydrocarbon resources in the Caspian Sea by these states should be carried out jointly.
In the literature, there has been a proposal to give the Caspian Sea the status of a “sui generis” lake, and in this case we are talking about a special international legal status of such a lake and its special regime. Under the regime is assumed the joint development by states of their own rules for the use of its resources.
Thus, the recognition of the Caspian Sea as a lake does not require its mandatory division into sectors - each coastal state has its own part. In addition, there are no norms in international law on the division of lakes between states: this is their good will, behind which certain internal interests may be hidden.
At present, all the Caspian states recognize that the modern legal regime was established by the established practice of its use, but now the Caspian is in actual common use not by two, but by five states. Even at the meeting of foreign ministers held in Ashgabat on November 12, 1996, the Caspian states confirmed that the status of the Caspian Sea could be changed only with the consent of all five coastal states. Later, this was also confirmed by Russia and Azerbaijan in a joint statement dated January 9, 2001 on the principles of cooperation, as well as in the Declaration on cooperation in the Caspian Sea signed between Kazakhstan and Russia dated October 9, 2000.
But in the course of numerous Caspian negotiations, conferences and four summits of the Caspian states (Ashgabat summit on April 23-24, 2002, the Tehran summit on October 16, 2007, the Baku summit on November 18, 2010 and Astrakhan on September 29, 2014), the consent of the Caspian countries it has not been possible to achieve.
More productive so far is cooperation at the bilateral and trilateral levels. Back in May 2003, Russia, Azerbaijan and Kazakhstan signed an agreement on the junction of the lines of delimitation of adjacent sections of the bottom of the Caspian Sea, which was based on previous bilateral agreements. In the current situation, Russia, by its participation in these agreements, seemed to confirm that the agreements between the USSR and Iran are outdated and do not correspond to existing realities.
In the Agreement of July 6, 1998 between the Russian Federation and the Republic of Kazakhstan on the delimitation of the bottom of the northern part of the Caspian Sea in order to exercise sovereign rights to subsoil use, the delimitation of the sea bottom between adjacent and opposite sides along a modified median line was announced on the basis of the principle of justice and agreement of the parties. At the bottom of the section, the states have sovereign rights, but their common use of the water surface is preserved.
Iran perceived this agreement as separate and violating the previous Treaties with the USSR of 1921 and 1940. However, it should be noted that in the preamble of the 1998 agreement, to which Russia and Kazakhstan were parties, the agreement was considered as a temporary measure pending the signing of the convention by all the Caspian states.
Later, on July 19 of the same year, Iran and Russia made a joint statement in which they proposed three possible scenarios for the delimitation of the Caspian Sea. First: the sea should be shared on the basis of the condominium principle. The second scenario boils down to dividing the water area, waters, bottom and subsoil into national sectors. The third scenario, which is a compromise between the first and second options, suggests dividing only the bottom between the coastal states, and considers the water surface to be common and open to all coastal countries.
The existing options for the delimitation of the Caspian Sea, including those mentioned above, are possible only if there is good political will on the part of the parties. Azerbaijan and Kazakhstan have clearly expressed their position from the very beginning of the process of multilateral consultations. Azerbaijan considers the Caspian Sea to be a lake and, therefore, it should be divided. Kazakhstan proposes to consider the Caspian as a closed sea, referring to the 1982 UN Convention (Articles 122, 123), and, accordingly, stands for its division in the spirit of the Convention. Turkmenistan has long supported the idea of joint management and use of the Caspian, but foreign companies already developing resources off the coast of Turkmenistan have influenced the policy of its president, who began to object to the establishment of a condominium regime, supporting the position of dividing the sea.
Azerbaijan was the first of the Caspian states to start using the hydrocarbon resources of the Caspian under the new conditions. After the signing of the "Deal of the Century" in September 1994, Baku expressed a desire to declare the sector adjacent to it an integral part of its territory. This provision was also enshrined in the Constitution of Azerbaijan, adopted in order to exercise sovereign rights to subsoil use, Moscow, July 6, 1998 at a referendum on November 12, 1995 (Article 11). But such a radical position from the very beginning did not correspond to the interests of all other coastal states, especially Russia, which expresses fears that this will open access to the Caspian Sea to countries in other regions. Azerbaijan agreed to a compromise. In the Agreement between the Russian Federation and Azerbaijan on the delimitation of adjacent sections of the Caspian Sea in 2002, a provision was fixed in which the division of the bottom was carried out using the median line, and the water area of the reservoir remained in joint use.
Unlike Azerbaijan, which expressed a desire to completely divide the Caspian, Iran proposes to leave its bowels and water for joint use, but does not object to the option of dividing the Caspian into 5 equal parts. Accordingly, each member of the Caspian five would be allocated 20 percent of the total territory of the reservoir.
Russia's point of view was changing. For a long time Moscow insisted on the establishment of a condominium, but wanting to build a long-term policy with neighbors who did not benefit from considering the Caspian as the property of five coastal states, it changed its position. This then prompted the states to start new stage negotiations, at the end of which, in 1998, the above Agreement was signed, where Russia declared that it was "ripe" for the division of the Caspian. Its main principle was the position "the water is common - we divide the bottom."
Taking into account the fact that some of the Caspian states, namely Azerbaijan, Kazakhstan and Russia, have reached agreements on the conditional delimitation of spaces in the Caspian, it can be concluded that they are actually satisfied with the already established regime with the division of its bottom along a modified median line and the joint use of the surface reservoir for navigation and fishing.
However, the lack of complete clarity and unity in the position of all countries of the coast prevents the Caspian states themselves from developing oil production. And oil is of key importance to them. There are no unequivocal data regarding their reserves in the Caspian Sea. According to the US Energy Information Agency in 2003, the Caspian was ranked second in oil reserves and third in gas reserves. The data of the Russian side is different: they speak of an artificial overestimation by Western experts of the energy resources of the Caspian Sea. Differences in assessments are due to the political and economic interests of regional and external players. The data distortion factor was the geopolitical significance of the region, with which the foreign policy plans of the US and the EU are connected. Zbigniew Brzezinski back in 1997 expressed the opinion that this region is the "Eurasian Balkans".
CASPIAN SEA (Caspian), the world's largest enclosed body of water, drainless brackish lake. Located on the southern border of Asia and Europe, it washes the shores of Russia, Kazakhstan, Turkmenistan, Iran and Azerbaijan. Because of the size, originality natural conditions and complexity of hydrological processes The Caspian Sea is usually referred to the class of closed inland seas.
The Caspian Sea is located in a vast area of internal flow and occupies a deep tectonic depression. The water level in the sea is at around 27 m below the level of the World Ocean, the area is about 390 thousand km 2, the volume is about 78 thousand km 3. The greatest depth is 1025 m. With a width of 200 to 400 km, the sea is elongated along the meridian for 1030 km.
The largest bays: in the east - Mangyshlak, Kara-Bogaz-Gol, Turkmenbashi (Krasnovodsk), Turkmen; in the west - Kizlyar, Agrakhan, Kyzylagadzh, Baku Bay; in the south - shallow lagoons. There are many islands in the Caspian Sea, but almost all of them are small, with total area less than 2 thousand km 2. In the northern part, there are numerous small islands adjacent to the Volga delta; larger ones - Kulaly, Morskoy, Tyuleniy, Chechen. Off the western shores is the Apsheron archipelago, to the south lie the islands of the Baku archipelago, off the eastern coast is the narrow island of Ogurchinsky, elongated from north to south.
The northern shores of the Caspian Sea are low-lying and very sloping, characterized by a wide development of droughts formed as a result of surge phenomena; deltaic shores are also developed here (the deltas of the Volga, the Urals, and the Terek) with an abundant supply of terrigenous material; the Volga delta stands out with extensive reed beds. Western shores abrasion, south of Absheron Peninsula mostly accumulative delta type with numerous bays and spits. southern shores base. The eastern shores are mostly deserted and low-lying, composed of sands.
relief and geological structure bottom.
The Caspian Sea is located in a zone of increased seismic activity. In the city of Krasnovodsk (now Turkmenbashi) in 1895 there was a strong earthquake measuring 8.2 on the Richter scale. Eruptions of mud volcanoes are often observed on the islands and the coast of the southern part of the sea, leading to the formation of new shoals, banks and small islands, blurred by excitement and reappearing.
According to the peculiarities of physical and geographical conditions and the nature of the bottom topography in the Caspian Sea, it is customary to distinguish the Northern, Middle and Southern Caspian. The Northern Caspian is characterized by exceptionally shallow water, located completely within the shelf with average depths of 4-5 m. Even small changes in the level here at low coasts lead to significant fluctuations in the area of the water mirror, therefore, the boundaries of the sea in the northeastern part on small-scale maps are shown by a dotted line. The greatest depths (about 20 m) are observed only near the conditional border with the Middle Caspian, which is drawn along the line connecting Chechen Island (to the north of the Agrakhan Peninsula) with Tyub-Karagan Cape on the Mangyshlak Peninsula. In the relief of the bottom of the Middle Caspian, the Derbent depression stands out (the greatest depth is 788 m). The boundary between the Middle and South Caspian passes over the Apsheron threshold with depths up to 180 m along the line from Chilov Island (to the east of the Absheron Peninsula) to Cape Kuuli (Turkmenistan). The basin of the South Caspian is the most extensive area of the sea with the greatest depths, almost 2/3 of the waters of the Caspian Sea are concentrated here, 1/3 falls on the Middle Caspian, and less than 1% of the Caspian waters are located in the North Caspian due to shallow depths. In general, the shelf areas (the entire northern part and a wide strip along the eastern coast of the sea) predominate in the bottom relief of the Caspian Sea. The continental slope is most pronounced on western slope Derbent basin and almost along the entire perimeter of the South Caspian basin. On the shelf, terrigenous-shell sands, shells, and oolitic sands are common; deep-water areas of the bottom are covered with silty and silty sediments with a high content of calcium carbonate. In some areas of the bottom, Neogene bedrocks are exposed. Mirabilite accumulates in the Ka-ra-Bogaz-Gol Bay.
In tectonic terms, within the Northern Caspian, the southern part of the Caspian syneclise of the East European platform is distinguished, which is framed in the south by the Astrakhan-Aktobe zone, composed of Devonian-Lower Permian carbonate rocks, occurring on a volcanic base and containing large deposits of oil and natural combustible gas. Paleozoic folded formations of the Donetsk-Caspian zone (or the Karpinsky ridge) are pushed onto the syneclise from the southwest, which is a protrusion of the basement of the young Scythian (in the west) and Turan (in the east) platforms, which are separated at the bottom of the Caspian Sea by the Agrakhan-Guryev fault (left shift) of northeast strike. The Middle Caspian mainly belongs to the Turan platform, and its southwestern margin (including the Derbent depression) is a continuation of the Terek-Caspian foredeep of the Greater Caucasus fold system. The sedimentary cover of the platform and trough, composed of Jurassic and younger sediments, contains oil and combustible gas deposits in local uplifts. The Apsheron Sill, which separates the Middle Caspian from the South, is a connecting link of the Cenozoic folded systems of the Greater Caucasus and the Kopetdag. The South Caspian Basin of the Caspian Sea with crust of oceanic or transitional type is filled with a thick (over 25 km) complex of Cenozoic sediments. Numerous large hydrocarbon deposits are concentrated in the South Caspian Basin.
Until the end of the Miocene, the Caspian Sea was a marginal sea of the ancient Tethys Ocean (since the Oligocene, the relic oceanic basin of the Paratethys). By the beginning of the Pliocene, it lost contact with the Black Sea. The Northern and Middle Caspians were drained, and the paleo-Volga valley stretched through them, the delta of which was located in the area of the Apsheron Peninsula. Delta sediments have become the main reservoir of oil and natural combustible gas deposits in Azerbaijan and Turkmenistan. In the late Pliocene, due to the Akchagyl transgression, the area of the Caspian Sea greatly increased and the connection with the World Ocean temporarily resumed. The waters of the sea covered not only the bottom of the modern depression of the Caspian Sea, but also the adjacent territories. In the Quaternary, transgressions (Absheron, Baku, Khazar, Khvalyn) alternated with regressions. The southern half of the Caspian Sea is located in a zone of increased seismic activity.
Climate. The Caspian Sea, strongly elongated from north to south, is located within several climatic zones. In the northern part the climate is temperate continental, on the western coast - temperate warm, southwestern and south coast lie within the subtropics, on the east coast dominated by a desert climate. In winter, the weather over the North and Middle Caspian is formed under the influence of the Arctic continental and sea air, and the South Caspian is often under the influence of southern cyclones. The weather in the west is unstable rainy, in the east it is dry. In summer, the western and northwestern regions are influenced by the spurs of the Azores atmospheric maximum, and the southeastern regions are influenced by the Iran-Afghan minimum, which together creates dry, stable warm weather. Winds from the north and northwest (up to 40%) and southeast (about 35%) directions prevail over the sea. The average wind speed is about 6 m/s, in central regions sea up to 7 m/s, in the area of the Apsheron Peninsula - 8-9 m/s. Northern storm "Baku Nords" reach speeds of 20-25 m/s. Lowest average monthly temperatures air -10 °С are observed in January - February in the northeastern regions (in the most harsh winters reach -30 °С), in the southern regions 8-12 °С. In July - August, the average monthly temperatures over the entire sea area are 25-26 °С, with a maximum of up to 44 °С on the east coast. The distribution of atmospheric precipitation is very uneven - from 100 mm per year on the eastern shores to 1700 mm in Lankaran. In the open sea, on average, about 200 mm of precipitation falls annually.
hydrological regime. Changes in the water balance of an enclosed sea strongly affect the change in the volume of water and the corresponding level fluctuations. Average long-term components of the water balance of the Caspian Sea for the 1900-90s (km 3 / cm layer): river runoff 300/77, precipitation 77/20, underground runoff 4/1, evaporation 377/97, runoff in Kara-Bogaz- Goal 13/3, which forms a negative water balance of 9 km 3 or 3 cm layer per year. According to paleogeographic data, over the past 2000 years, the range of fluctuations in the level of the Caspian Sea has reached at least 7 m. -29 m (the lowest position in the last 500 years). The sea surface area has decreased by more than 40 thousand km 2, which exceeds the area Sea of Azov. Since 1978, a rapid rise in level began, and by 1996 a mark of about -27 m relative to the level of the World Ocean was reached. In the modern era, fluctuations in the level of the Caspian Sea are determined mainly by fluctuations in climatic characteristics. Seasonal fluctuations in the level of the Caspian Sea are associated with the uneven flow of river flow (primarily the flow of the Volga), so the lowest level is observed in winter, the highest in summer. Short-term sharp changes in the level are associated with surge phenomena, they are most pronounced in shallow waters. northern regions and during storm surges can reach 3-4 m. Such surges cause flooding of significant coastal land areas. In the Middle and South Caspian, surge fluctuations in the level are on average 10-30 cm, under storm conditions - up to 1.5 m. The frequency of surges, depending on the area, is from one to 5 times a month, the duration is up to one day. In the Caspian, as in any closed reservoir, seiche fluctuations in the level are observed in the form of standing waves with periods of 4-9 hours (wind) and 12 hours (tidal). The magnitude of seiche fluctuations usually does not exceed 20–30 cm.
River flow in the Caspian Sea is distributed extremely unevenly. More than 130 rivers flow into the sea, which, on average, bring about 290 km 3 of fresh water per year. Up to 85% of the river flow falls on the Volga with the Urals and enters the shallow Northern Caspian. Rivers west coast- Kura, Samur, Sulak, Terek, etc. - give up to 10% of the runoff. About 5% more fresh water are brought to the South Caspian by the rivers of the Iranian coast. The eastern desert shores are completely devoid of constant fresh water.
The average speed of wind currents is 15-20 cm/s, the highest - up to 70 cm/s. In the North Caspian, the prevailing winds create a flow directed along the northwestern coast to the southwest. In the Middle Caspian, this current merges with the western branch of the local cyclonic circulation and continues to move along the western coast. At the Absheron Peninsula, the current bifurcates. Its part in the open sea flows into the cyclonic circulation of the Middle Caspian, and the coastal part goes around the shores of the South Caspian and turns to the north, joining the coastal current, enveloping the entire eastern coast. The average state of the movement of the Caspian surface waters is often disturbed due to the variability of wind conditions and other factors. Thus, in the northeastern shallow area, a local anticyclonic gyre can occur. Two anticyclonic eddies are often observed in the South Caspian. In the Middle Caspian, during the warm season, steady northwest winds create southward transport along the east coast. In light winds and during calm weather, the currents may have other directions.
Wind waves develop very strongly, since the prevailing winds have great length overclocking. The excitement develops mainly in the northwestern and southeastern directions. Severe storms are observed in the open waters of the Middle Caspian, in the areas of the city of Makhachkala, the Apsheron Peninsula and the Mangyshlak Peninsula. The average wave height of the highest frequency is 1-1.5 m, at wind speeds of more than 15 m/s it increases to 2-3 m. 10 m
The water temperature on the sea surface in January - February in the North Caspian is close to freezing (about -0.2 - -0.3 °C) and gradually rises southward to 11 °C off the coast of Iran. In summer surface water warm up to 23-28 °С everywhere, except for the eastern shelf of the Middle Caspian, where seasonal coastal upwelling develops in July-August and the water temperature on the surface drops to 12-17 °С. In winter, due to intense convective mixing, the water temperature changes little with depth. In summer, under the upper heated layer at the horizons of 20-30 m, a seasonal thermocline (a layer of sharp temperature change) is formed, separating deep cold waters from warm surface waters. In the bottom layers of water deep sea trenches All year round the temperature is 4.5-5.5 °C in the Middle Caspian and 5.8-6.5 °C in the South. The salinity in the Caspian Sea is almost 3 times lower than in the open areas of the World Ocean, and averages 12.8-12.9‰. It should be especially emphasized that salt composition Caspian water is not completely identical to the composition ocean waters due to the isolation of the sea from the ocean. The waters of the Caspian Sea are poorer in sodium salts and chlorides, but richer in calcium and magnesium carbonates and sulfates due to the unique composition of salts entering the sea with river and underground runoff. The highest variability of salinity is observed in the Northern Caspian, where in the estuarine sections of the Volga and the Urals the water is fresh (less than 1‰), and as you move south, the salt content increases to 10-11‰ at the border with the Middle Caspian. The greatest horizontal salinity gradients are characteristic of the frontal zone between the sea and river waters. Differences in salinity between the Middle and South Caspian are small, salinity slightly increases from northwest to southeast, reaching 13.6‰ in the Turkmen Gulf (up to 300‰ in Kara-Bogaz-Gol). Salinity changes along the vertical are small and rarely exceed 0.3‰, which indicates a good vertical mixing water. Water transparency varies over a wide range from 0.2 m in the mouth areas of large rivers to 15-17 m in the central regions of the sea.
According to the ice regime, the Caspian Sea belongs to partially freezing seas. Ice conditions are observed annually only in the northern regions. The Northern Caspian is completely covered with sea ice, the Middle - partially (only in severe winters). The average sea ice boundary runs along an arc with a bulge to the north, from the Agrakhan Peninsula in the west to the Tyub-Karagan Peninsula in the east. Usually, ice formation begins in mid-November in the extreme northeast and gradually spreads to the southwest. In January, the entire Northern Caspian is covered with ice, mostly landfast ice (fixed). Drifting ice borders the fast ice with a strip 20-30 km wide. The average thickness of ice is from 30 cm at the southern border to 60 cm in the northeastern regions of the Northern Caspian, in hummocky heaps - up to 1.5 m. The destruction of the ice cover begins in the 2nd half of February. In severe winters, drifting ice is carried to the south, along West Bank, sometimes to the Apsheron Peninsula. In early April, the sea is completely free of ice cover.
Research history. It is believed that the modern name of the Caspian Sea comes from the ancient tribes of the Caspians, who inhabited the coastal regions in the 1st millennium BC; other historical names: Hyrkan (Irkan), Persian, Khazar, Khvalyn (Khvalis), Khorezm, Derbent. The first mention of the existence of the Caspian Sea dates back to the 5th century BC. Herodotus was one of the first to argue that this reservoir is isolated, that is, it is a lake. In the works of Arab scientists of the Middle Ages, there is information that in the 13-16 centuries the Amu Darya partially flowed into this sea by one of the branches. The well-known numerous ancient Greek, Arabic, European, including Russian, maps of the Caspian Sea until the beginning of the 18th century did not reflect reality and were in fact arbitrary drawings. By order of Tsar Peter I, an expedition was organized in 1714-15 under the leadership of A. Bekovich-Cherkassky, who explored the Caspian Sea, in particular its eastern shores. The first map, on which the contours of the coasts are close to modern ones, was compiled in 1720 using astronomical definitions by Russian military hydrographers F. I. Soymonov and K. Verden. In 1731, Soimonov published the first atlas, and soon the first printed sailing direction of the Caspian Sea. A new edition of the maps of the Caspian Sea with corrections and additions was carried out by Admiral A. I. Nagaev in 1760. The first information on the geology and biology of the Caspian Sea was published by S. G. Gmelin and P. S. Pallas. Hydrographic research in the 2nd half of the 18th century was continued by I.V. Tokmachev, M.I. Voinovich, at the beginning of the 19th century - by A.E. Kolodkin, who was the first to perform instrumental compass survey of the coast. Published in 1807 new map of the Caspian Sea, compiled taking into account the latest inventories. In 1837, systematic instrumental observations of sea level fluctuations began in Baku. In 1847, the first complete description of the Kara-Bogaz-Gol Bay was made. In 1878, the General Map of the Caspian Sea was published, which reflected the results of the latest astronomical observations, hydrographic surveys, and depth measurements. In 1866, 1904, 1912–13, and 1914–15, under the leadership of N. M. Knipovich, expeditionary studies were carried out in the hydrology and hydrobiology of the Caspian Sea; in 1934, a Commission for the Comprehensive Study of the Caspian Sea was established under the Academy of Sciences of the USSR. A great contribution to the study of the geological structure and oil content of the Apsheron Peninsula and the geological history of the Caspian Sea was made by Soviet geologists I. M. Gubkin, D. V. and V. D. Golubyatnikovs, P. A. Pravoslavlev, V. P. Baturin, S. A . Kovalevsky; in the study of water balance and sea level fluctuations - B. A. Appolov, V. V. Valedinsky, K. P. Voskresensky, L.S. Berg. After the Great Patriotic War, systematic diversified studies were launched in the Caspian Sea, aimed at studying the hydrometeorological regime, biological conditions and the geological structure of the sea.
In the 21st century in Russia, two major scientific centers. Caspian Marine Research Center (KaspMNIC), established in 1995 by a government decree Russian Federation, conducts research work on hydrometeorology, oceanography and ecology. The Caspian Research Institute of Fisheries (CaspNIRKH) traces its history from the Astrakhan Research Station [established in 1897, since 1930 the Volga-Caspian Scientific Fisheries Station, since 1948 the Caspian Branch of the All-Russian Research Institute of Fisheries and Oceanography, since 1954 the Caspian Research Institute of Marine Fisheries and Oceanography (KaspNIRO), modern name since 1965]. CaspNIRKh is developing the foundations for the conservation and rational use biological resources Caspian Sea. It consists of 18 laboratories and scientific departments - in Astrakhan, Volgograd and Makhachkala. It has a scientific fleet of more than 20 ships.
Economic use. The natural resources of the Caspian Sea are rich and varied. Significant hydrocarbon reserves are being actively developed by Russian, Kazakh, Azerbaijani and Turkmen oil and gas companies. There are huge reserves of mineral self-saddle salts in the Kara-Bogaz-Gol Bay. The Caspian region is also known as a massive habitat for waterfowl and near-water birds. About 6 million migratory birds migrate through the Caspian Sea every year. In this regard, the Volga delta, Kyzylagadzh, Northern Cheleken and Turkmenbashi bays are recognized as sites of international rank under the Ramsar Convention. The estuarine sections of many rivers flowing into the sea have unique types of vegetation. The fauna of the Caspian Sea is represented by 1800 animal species, of which 415 species are vertebrates. More than 100 species of fish live in the sea and estuaries of rivers. are of commercial importance sea views- herring, sprat, gobies, sturgeons; freshwater - carp, perch; arctic "invaders" - salmon, white salmon. Major ports: Astrakhan, Makhachkala in Russia; Aktau, Atyrau in Kazakhstan; Turkmenbashi in Turkmenistan; Bandar Torkemen, Bandar Anzeli in Iran; Baku in Azerbaijan.
Ecological state. The Caspian Sea is under a powerful anthropogenic impact due to the intensive development of hydrocarbon deposits and the active development of fishing. In the 1980s, the Caspian Sea produced up to 80% of the world's sturgeon catch. Predatory catches of recent decades, poaching and a sharp deterioration in the ecological situation have put many valuable fish species on the brink of extinction. Habitat conditions have deteriorated not only for fish, but also for birds and marine animals (Caspian seal). The countries washed by the waters of the Caspian Sea face the problem of creating a set of international measures to prevent pollution of the aquatic environment and developing the most effective environmental strategy for the near future. A stable ecological state is noted only in parts of the sea remote from the coast.
Lit.: Caspian Sea. M., 1969; Complex studies of the Caspian Sea. M., 1970. Issue. 1; Gul K.K., Lappalainen T.N., Polushkin V.A. The Caspian Sea. M., 1970; Zalogin B. S., Kosarev A. N. Morya. M., 1999; International tectonic map Caspian Sea and its framing / Ed. V. E. Khain, N. A. Bogdanov. M., 2003; Zonn I. S. Caspian Encyclopedia. M., 2004.
M. G. Deev; V. E. Khain (geological structure of the bottom).
The Caspian Sea is the most big lake On the Earth. It is called the sea because of its size and bed, which is folded like an ocean basin. The area is 371,000 square meters, the depth is 1025 m. The list of rivers flowing into the Caspian Sea includes 130 names. The largest of them are: Volga, Terek, Samur, Sulak, Ural and others.
Caspian Sea
It took 10 million years before the Caspian was formed. The reason for its formation is that the Sarmatian Sea, which lost its connection with the World Ocean, was divided into two reservoirs, which were called the Black and Caspian Seas. Between the latter and the World Ocean stretch thousands of kilometers of waterless path. It is located at the junction of two continents - Asia and Europe. Its length in the north-south direction is 1200 km, west-east - 195-435 km. The Caspian Sea is an internal drainless basin of Eurasia.
Near the Caspian Sea, the water level is below the level of the World Ocean, and besides, it is subject to fluctuations. According to scientists, this is due to many factors: anthropogenic, geological, climatic. At present, the average water level reaches 28 m.
The network of rivers and sewage is unevenly distributed along the coast. To the part of the sea with north side Few rivers flow into it: Volga, Terek, Ural. From the west - Samur, Sulak, Kura. The east coast is characterized by the absence of permanent watercourses. Differences in space in the flow of water that rivers bring to the Caspian Sea is an important geographical feature of this reservoir.
Volga
This river is one of the largest in Europe. In Russia, it ranks sixth in size. In terms of catchment area, it is second only to Siberian rivers flowing into the Caspian Sea, such as the Ob, Lena, Yenisei, Irtysh. For the source, from where the Volga originates, the key is taken near the village of Volgoverkhovye, Tver Region, on the Valdai Upland. Now there is a chapel at the source, which attracts the attention of tourists, for whom it is a pride to step over the very beginning of the mighty Volga.
A small fast stream gradually gains strength and becomes a huge river. Its length is 3690 km. The source is 225 m above sea level. Among the rivers flowing into the Caspian Sea, the largest is the Volga. Her path runs through many regions of our country: Tver, Moscow, Nizhny Novgorod, Volgograd and others. The territories through which it flows are Tatarstan, Chuvashia, Kalmykia and Mari El. The Volga is the location of millionaire cities - Nizhny Novgorod, Samara, Kazan, Volgograd.
Volga Delta
The main riverbed is divided into channels. A certain shape of the mouth is formed. It's called the delta. Its beginning is the place of separation of the Buzan branch from the bed of the Volga river. The delta is located 46 km north of the city of Astrakhan. It includes channels, branches, small rivers. There are several main branches, but only Akhtuba is navigable. Among all the rivers of Europe, the Volga is distinguished by the largest delta, which is a rich fish region in this basin.
It lies 28 m lower than the ocean level. The mouth of the Volga is the location of the southernmost Volga city of Astrakhan, which in the distant past was the capital of the Tatar Khanate. Later, at the beginning of the 18th century (1717), Peter 1 gave the city the status of "the capital of the province of Astrakhan." During his reign, the main attraction of the city, the Assumption Cathedral, was built. Its Kremlin is made of white stone, brought from the capital of the Golden Horde, the city of Saray. The mouth is divided by branches, the largest of which are: Bolda, Bakhtemir, Buzan. Astrakhan is a southern city located on 11 islands. Today it is a city of shipbuilders, sailors and fishermen.
Currently, the Volga needs protection. For this purpose, a reserve has been established at the place where the river flows into the sea. Volga Delta, largest river, flowing into the Caspian Sea, abounds unique flora and fauna: sturgeon, lotuses, pelicans, flamingos and others. Immediately after the revolution of 1917, a law was passed on their protection by the state as part of the Astrakhan Reserve.
Sulak River
It is located in Dagestan, flows through its territory. It feeds on the waters of melted snows that flow down from the mountains, as well as tributaries: Small Sulak, Chvakhun-bak, Akh-su. Water also enters Sulak through a canal from the Aksai and Aktash rivers.
The source is formed by the confluence of two rivers that originate in the basins: Didoyskaya and Tushinskaya. The length of the Sulak River is 144 km. Its pool has a fairly large area - 15,200 square meters. It flows through the canyon with the same name as the river, then through the Akhetlinsky gorge and finally comes to the plane. Going around the Agrakhan Bay with south side, Sulak flows into the sea.
The river provides drinking water to Kaspiysk and Makhachkala, it is home to hydroelectric power plants, the urban-type settlements of Sulak and Dubki, and small town Kizilyurt.
Samur
The river got its name not by chance. The name translated from the Caucasian language (one of them) means "middle". Indeed, the border between the states of Russia and Azerbaijan is marked along the waterway along the Samur River.
The sources of the river are glaciers and springs, originating in the spurs of the Caucasus Range from the northeast side, not far from the Guton mountain. The height above sea level is 3200 m. Samur has a length of 213 km. The height in the upper reaches and the mouth differs by three kilometers. The catchment basin has an area of almost five thousand square meters.
The places where the river flows are narrow gorges located between mountains of great height, composed of shales and sandstones, which is why the water here is muddy. The Samur basin has 65 rivers. Their length reaches 10 km or more.
Samur: the valley and its description
The valley of this river in Dagestan is the most densely populated region. Derbent is located near the mouth - ancient city peace. The banks of the Samur River are home to twenty or more species of relict representatives of the flora. Endemic, endangered and rare species listed in the Red Book grow here.
In the river delta, a relict forest is comfortably located, which is the only one in Russia. Liana forest is a fairy tale. Huge trees of the rarest and most common species grow here, intertwined with lianas. The river is rich in valuable species of fish: mullet, pike perch, pike, catfish and others.
Terek
The river got its name from the Karachay-Balkar peoples who lived along its banks. They called it "Terk Suu", which means "rushing water" in translation. Ingush and Chechens called it Lomeki - "mountain water".
The beginning of the river is the territory of Georgia, the Zigla-Khokh glacier - a mountain located on the slope of the Caucasus Range. It is under glaciers all year round. One of them melts when sliding down. A small stream is formed, which is the source of the Terek. It is located at an altitude of 2713 m above sea level. The length of the river flowing into the Caspian Sea is 600 km. At the confluence with the Caspian, the Terek is divided into many branches, as a result of which a vast delta is formed, its area is 4000 square meters. In some places it is very swampy.
The course in this place has changed several times. The old arms have now been turned into canals. The middle of the last century (1957) was marked by the construction of the Kargaly hydroelectric complex. It is used to supply water to the channels.
How is the Terek replenished?
The river has a mixed supply, but for upstream An important role is played by the waters from the melting of glaciers, they fill the river. In this regard, 70% of the runoff occurs in spring and summer, that is, at this time the water level in the Terek is the highest, and the lowest is in February. The river freezes if the winters are characterized by a harsh climate, but the freeze-up is unstable.
The river is not distinguished by cleanliness and transparency. The turbidity of the water is large: 400-500 g/m 3 . Every year, the Terek and its tributaries pollute the Caspian Sea, pouring into it from 9 to 26 million tons of various suspensions. This is due to the rocks of which the shores are composed, and they are clayey.
Terek mouth
The Sunzha is the largest tributary flowing into the Terek, the lower reaches of which are measured precisely from this river. By this time, the Terek flows for a long time over the flat terrain, leaving the mountains located behind the Elkhot Gates. The bottom here is composed of sand and pebbles, the current slows down, and in some places stops altogether.
The mouth of the Terek River has an unusual appearance: the channel here is elevated above the valley, in appearance it resembles a canal, which is fenced with a high embankment. The water level rises above the land level. This phenomenon is due to a natural cause. Since the Terek is a stormy river, it brings sand and stones from the Caucasian ridge to in large numbers. Given that the current in the lower reaches is weak, some of them settle here and do not reach the sea. For the inhabitants of the area, sediments are both a threat and a boon. When they are washed away by water, floods of great destructive power occur, this is very bad. But in the absence of floods, the soils become fertile.
Ural river
In ancient times (until the second half of the 18th century), the river was called Yaik. It was renamed into the Russian style by the decree of Catherine II in 1775. Just at this time, the Peasant War was suppressed, the leader of which was Pugachev. The name is still preserved in the Bashkir language, and in Kazakhstan it is official. The Urals are the third longest in Europe, only the Volga and the Danube are larger than this river.
The Ural originates in Russia, on the slope of the Kruglyaya Sopka of the Uraltau Ridge. The source is a spring gushing out of the ground at an altitude of 637 m above sea level. At the beginning of its journey, the river flows in a north-south direction, but after meeting a plateau on the way, it makes a sharp turn and continues to flow in a north-westerly direction. However, beyond Orenburg, its direction again changes to the southwestern, which is considered the main one. Having overcome the winding path, the Ural flows into the Caspian Sea. The length of the river is 2428 km. The mouth is divided into branches and tends to shallow.
The Ural is a river along which the natural water boundary between Europe and Asia passes, with the exception of the upper reaches. This is an internal European river, but its upper reaches to the east of the Ural Range are the territory of Asia.
Importance of the Caspian rivers
The rivers flowing into the Caspian Sea are of great importance. Their waters are used for human and animal consumption, domestic needs, agricultural and industrial needs. Hydroelectric power plants are being built on the rivers, the energy of which is in demand by man for various purposes. River basins are full of fish, algae, shellfish. Even in ancient times, people chose river valleys for future settlements. And now cities and towns are being built on their banks. Rivers ply passenger and transport ships, performing important tasks for the transport of passengers and goods.
Caspian Sea or Caspian Lake?
An amazing body of water located at the junction of Europe and Asia was called the Caspian Sea. Today it is not difficult to find it on a geographical map, since its waters wash the shores of 5 states at once. Although not everyone agrees that this is the sea. Many experts say that this is a huge lake in size. Indeed, the Caspian Sea does not have a direct outlet to the World Ocean, but is connected with it only through the Volga River.
However, some time ago, the Sarmatian Sea was located on this territory, which disappeared due to climatic conditions, and more shallow seas, including the Caspian. The waters of the Caspian Sea are quite deep, and its bottom is the earth's crust. This is another argument for calling this body of water a sea.
Depth and temperature
The Caspian Sea is heterogeneous in its depth and at different times different depth indicators can be observed here. All this depends on the season. According to scientists, the recorded depth of the sea is 1025 meters. Those scientists who rank the Caspian Sea as a lake in terms of depth put it in fourth place in the world.
Washing the shores of Russia, Iran, Kazakhstan, Azerbaijan and Turkmenistan, the lake-sea is becoming more and more popular with tourists. The lake almost never freezes. The temperature regime of water in the Caspian reaches 28 degrees, and in places where the depth is less, the water can warm up to 32 degrees.
Climate
The waters of the Caspian are located in three different climatic zones. Subtropical in the south, temperate in the middle and continental in the north. Depending on the climatic zone, fluctuations in temperature indicators are observed. On average, the temperature reaches 26-27 degrees, but in the south it is possible to increase the air temperature to 44 degrees.
The inhabitants of the Caspian
The inner world of the Caspian Sea is very rich, various plants, mammals and hundreds of species of fish live in it. It is believed that some species of algae, which prevail in the Caspian Sea, got there from outside. The most famous species of fish living in the Caspian Sea belong to the sturgeon family.
The most most of The entire black caviar is mined in the Caspian Sea.
The Caspian Sea is also famous for such an inhabitant as the albino beluga, which spawns very rarely, about once every hundred years, so its caviar is considered the most expensive in the world. Today, the countries that own the waters of the Caspian are extremely interested in preserving the sturgeon population. For this, restrictions have been introduced on the export of this type of fish. Special place in the conservation of the famous species of fish is the fight against poaching, for this, various measures have also been developed to combat illegal fishing.
Resorts of the Caspian Sea
The Caspian Sea is an amazing place to relax, and those who decide to spend their holidays on the shores of the Caspian will not regret it. The Caspian Sea will attract everyone who comes here with its beauty, landscapes, air and its mild climate. Well-equipped beaches will complement the impressions of nature and the sea.
And quite affordable prices will be a pleasant bonus for those who choose the Caspian coast as a vacation spot. Russian cities- ports located on the shores of the Caspian Sea are the capital of Dagestan Makhachkala and the city of Derbent. Distance from the city-port of Astrakhan to north coast The Caspian Sea is 60 kilometers.
