Is it correct to call the Caspian Sea?
It is known that the sea is part of the World Ocean. From this geographically correct point of view, the Caspian Sea cannot be considered a sea, for it is separated from the ocean by huge tracts of land. The shortest distance from the Caspian to the Black Sea, the closest of the seas included in the World Ocean system, is 500 kilometers. Therefore, it would be more correct to speak of the Caspian as a lake. This largest lake in the world is often referred to simply as the Caspian or the sea-lake.
The Caspian Sea has a number of signs 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, North and even exceeds the area of the Azov and some others (however, the Canadian Lake Superior also has a huge area , like the three seas of Azov). Fierce storm winds and huge waves are frequent in the Caspian (and this is not uncommon on Lake Baikal).
So the Caspian Sea is a lake after all? That's on Wikipedia it is written And the Great Soviet Encyclopedia answers that no one has yet been able to give an exact definition of this issue - "There is no generally accepted classification."
Do you know why this is very important and fundamental? And here's why ...
The lake belongs to inland waters - sovereign territories of coastal states, to which the international regime does not apply (the principle of UN non-interference in the internal affairs of states). But the sea area is divided in a different way, and the rights of coastal states are completely different here.
In terms of its geographical position, the Caspian itself, in contrast to the surrounding land territories, for many centuries has not been the object of any targeted attention from the coastal states. Only at the beginning of the 19th century. The first treaties were concluded between Russia and Persia: Gulistan (1813) 4 and Turkmanchay (1828), summing up the results of the Russo-Persian war, as a result of which Russia annexed a number of Transcaucasian territories and received the exclusive right to maintain a military fleet in the Caspian sea. Russian and Persian merchants were allowed to trade freely on the territory of both states and use the Caspian for the transport of goods. The Turkmanchay agreement confirmed all these provisions and became the basis for the maintenance of international relations between the parties until 1917.
After the October Revolution of 1917, in a note from the new government of Russia that came to power on January 14, 1918, it renounced its exclusive military presence in the Caspian Sea. The treaty 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 reservoir for the common use of the parties: both states were granted equal rights of free navigation, except for cases when the crews of Iranian ships could include citizens of third countries using the service for unfriendly purposes (Article 7). The 1921 treaty did not provide for the 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 came under the new name. The parties confirmed the provisions of the 1921 treaty, but introduced into the agreement a new concept for the Caspian - a 10-mile fishing zone, which limited the spatial limits of this fishery for its participants. This was done in order to control and preserve 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 agreement on trade and navigation in the Caspian Sea between the USSR and Iran. 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 between the USSR and Iran, signed 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 the ships of only these two Caspian states. It also included a norm about 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 arisen. Instead of two states - the USSR and Iran, which previously bilaterally resolved all emerging issues of maritime navigation, fishing and the use of other living and nonliving resources, now there are five of them. Of the former, only Iran remained, the place of the USSR as succession was taken by Russia, the other three are new states: Azerbaijan, Kazakhstan, Turkmenistan. They had access to the Caspian before, 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 considering all the above issues. This was reflected in the attitude of these states towards the Caspian, since all five states that had access to it showed the same interest in the use of its living and nonliving 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 they are not the only ones.
In addition to the presence of rich mineral resources in the waters of the Caspian Sea, there are about 120 species and subspecies of fish, here is the world gene pool of sturgeon, the catch of which until recently amounted to 90% of their total world catch.
Due to its location, the Caspian has traditionally and for a long time been widely used for shipping, acting as a kind of transport artery between the peoples of the coastal states. On its shores are located such large seaports as the Russian Astrakhan, the capital of Azerbaijan Baku, the Turkmenbashi, Iranian Anzeli and Kazakhstan's Aktau, between which routes for the movement of trade, cargo and passenger sea transport have long been laid.
And yet, the main object of attention of the Caspian states is its mineral resources - oil and natural gas, which each of them can claim within the boundaries that must be determined by them collectively on the basis of international law. And to do this, they will have to divide between themselves the Caspian Sea and its bottom, in the depths 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 start of extensive production of the Caspian mineral resources 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 there is no agreement in their ranks so far. But at the same time, each of them seeks to start the production of Caspian oil and natural gas as soon as possible and make their sale abroad a permanent source of funds for the formation of their budget.
Therefore, the oil companies of Azerbaijan, Kazakhstan and Turkmenistan, without waiting for the end of the settlement of the existing differences on the territorial division of the Caspian, have already begun active production of its oil, hoping to stop being dependent on Russia, turn their countries into oil producing countries and, in this capacity, begin to build their own long-term trading relations with neighbors.
However, the question 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 to the territorial division of its water area and the bottom, or develop their own in this case.
Kazakhstan was in favor of recognizing the Caspian by the 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, territorial sea, exclusive economic zone, continental shelf. This would allow the coastal states to acquire sovereignty over the subsoil of the territorial sea (Art. 2) and exclusive rights to exploration and development of the resources of the continental shelf (Art. 77). But the Caspian cannot be called a sea from the standpoint of the 1982 UN Convention on the Law of the Sea, since this body of water is closed and has no natural connection with the world's oceans.
In this case, the option of joint use of 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 granting of the legal status of the "lake" to the Caspian Sea, it is supposed to be divided into sectors, as is done in relation 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 coastal states. Iran also considers the Caspian Sea as a lake from the position enshrined in treaties with the USSR. The government of the country believes that this status implies the creation of a consortium for the unified management of production and the use of its resources by the Caspian states. This opinion is also expressed by some authors, for example, R. Mamedov believes that with this status, the extraction of hydrocarbon resources in the Caspian 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 lake "sui generis", and in this case we are talking about the special international legal status of such a lake and its special regime. Under the regime, states are supposed to jointly develop their own rules for the use of its resources.
Thus, the recognition of the Caspian by a lake does not require its obligatory division into sectors - each coastal state has its own part. In addition, in international law, there are no norms at all 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 of not two, but five states. Back at the meeting of foreign ministers held in Ashgabat on November 12, 1996, the Caspian states confirmed that the status of the Caspian Sea can be changed only with the consent of all five coastal states. Later, this was also confirmed by Russia and Azerbaijan in a joint statement of 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 of 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, Tehran summit on October 16, 2007, Baku summit on November 18, 2010 and Astrakhan summit on September 29, 2014) it was never achieved.
Cooperation at the bilateral and trilateral levels is still more productive. Back in May 2003, Russia, Azerbaijan and Kazakhstan signed an agreement on the junction point of the delimitation lines of adjacent sections of the Caspian Sea bottom, which was based on previous bilateral agreements. In the current situation, by its participation in these agreements, Russia, as it were, confirmed that the agreements between the USSR and Iran are outdated and do not correspond to the 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, it was announced that the seafloor was delimited between adjacent and opposing sides along a modified median line based on the principle of justice and the agreement of the parties. The states have sovereign rights to the bottom of the plot, but at the same time their common use of the water surface is preserved.
Iran perceived this agreement as a separate one and in violation of the previous Treaties with the USSR in 1921 and 1940. However, it should be noted that in the preamble to the 1998 agreement, to which Russia and Kazakhstan were parties, the agreement was viewed 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. 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, assumes that only the seabed is divided between the coastal states, and the water surface is considered common and open to all coastal countries.
The existing options for the delimitation of the Caspian, including those mentioned above, are possible only if there is a good political will of the parties. Azerbaijan and Kazakhstan have clearly expressed their position from the very beginning of the multilateral consultation process. Azerbaijan considers the Caspian Sea to be a lake and, therefore, it should be divided. Kazakhstan proposes to consider the Caspian an enclosed sea, referring to the 1982 UN Convention (Articles 122, 123), and, accordingly, advocates 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 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 conclusion of the "Deal of the Century" in September 1994, Baku expressed a desire to declare the adjacent sector 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 areas of the Caspian Sea, 2002, a provision was fixed in which the seabed was divided 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 offers to leave its subsoil and water in 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 area of the reservoir.
Russia's point of view was changing. For a long time Moscow insisted on the establishment of a condominium, but wishing to build a long-term policy with its neighbors, who did not find it profitable to consider the Caspian as the property of the five coastal states, changed its position. This then pushed the states to start a new stage of negotiations, upon completion 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 “common water - 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, we can conclude that they are actually satisfied with the already established regime with the division of its bottom along the modified median line and the joint use of the surface reservoir for shipping and fishing.
However, the lack of complete clarity and unity in the position of all coastal countries prevents the Caspian states themselves from developing oil production. And oil is of key importance to them. There are no unambiguous 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 are different: they speak of artificial overstatement by Western experts of the energy resources of the Caspian Sea. The discrepancies in assessments are due to the political and economic interests of regional and external players. The factor of data distortion was the geopolitical significance of the region, with which the foreign policy plans of the United States and the EU are connected. Back in 1997, Zbigniew Brzezinski expressed the opinion that this region is the “Eurasian Balkans”.
The Caspian Sea is remarkable in that its western coast belongs to Europe, and the eastern one is located in Asia. This is a huge body of salt water. It is called the sea, but, in fact, it is a lake, since it has no connection with the World Ocean. Therefore, it can be considered the largest lake in the world.
The area of the water giant is 371 thousand square meters. km. As for the depth, the northern part of the sea is rather shallow, while the southern part is deep. The average depth is 208 meters, but it does not give any idea of the thickness of the water mass. The entire reservoir is divided into three parts. These are the North, Middle and South Caspian. The northern one is a sea shelf. It accounts for only 1% of the total volume of water. This part ends behind the Kizlyar Bay near the Chechen island. The average depth in these places is 5-6 meters.
In the Middle Caspian, the seabed is noticeably decreasing, and the average depth reaches 190 meters. The maximum is 788 meters. This part of the sea contains 33% of the total volume of water. And the South Caspian is considered the deepest. It absorbs 66% of the total water mass. The maximum depth was noted in the South Caspian depression. She is equal 1025 meters away and is considered the official maximum sea depth today. The Middle and South Caspian are approximately equal in area and occupy a total of 75% of the area of the entire reservoir.
The maximum length is 1030 km, and the corresponding width is 435 km. The minimum width is 195 km. The average figure is 317 km. That is, the reservoir has an impressive size and is rightfully called the sea. The length of the coastline, together with the islands, reaches almost 7 thousand km. As for the water level, it is 28 meters below the level of the World Ocean.
The most interesting thing is that the level of the Caspian Sea is subject to cyclicality. The water rises and falls. The water level has been measured since 1837. According to experts, over the past thousand years, the level fluctuated within 15 meters. This is a very large figure. And they associate it with geological and anthropogenic (human impact on the environment) processes. However, it was noted that since the beginning of the XXI century, the level of a huge reservoir has been steadily rising.
5 countries surround the Caspian Sea... These are Russia, Kazakhstan, Turkmenistan, Iran and Azerbaijan. Moreover, Kazakhstan has the longest coastline. Russia is in second place. But the length of the coastal line of Azerbaijan reaches only 800 km, but on the other hand, the largest port in the Caspian Sea is located in this place. This is, of course, Baku. The city is home to 2 million people, and the population of the entire Absheron Peninsula is 2.5 million people.
"Oil Rocks" - a city in the sea
These are 200 platforms with a total length of 350 kilometers.
Notable is the oilmen settlement, which bears the name " Oil Rocks". It is located 42 km east of Absheron in the sea and is a creation of human hands. All residential and industrial buildings are built on metal racks. People serve oil rigs pumping oil from the bowels of the earth. Of course, there are no permanent residents in this village.
In addition to Baku, other large cities are located along the shores of the salt reservoir. On the southern tip is the Iranian city of Anzali with a population of 111 thousand people. It is the largest Iranian port in the Caspian. Kazakhstan owns the city of Aktau with a population of 178 thousand people. And in the northern part, directly on the Ural River, there is the city of Atyrau. It is inhabited by 183 thousand people.
The Russian city of Astrakhan also has the status of a seaside city, although it is 60 km from the coast and is located in the Volga River delta. It is a regional center with a population of over 500 thousand people. Directly on the seashore are such Russian cities as Makhachkala, Kaspiysk, Derbent. The latter is one of the oldest cities in the world. People have been living in this place for over 5 thousand years.
Many rivers flow into the Caspian Sea. There are about 130 of them. The largest of them are the Volga, Terek, Ural, Kura, Atrek, Emba, Sulak. It is the rivers, not precipitation, that feed the huge reservoir. They give him up to 95% of water a year. The basin of the reservoir is 3.626 million square meters. km. These are all rivers with their tributaries flowing into the Caspian. The territory is huge, it includes and Kara-Bogaz-Gol Bay.
It would be more correct to call this bay a lagoon. It means a shallow body of water, separated from the sea by a sand bar or reefs. There is such a spit in the Caspian as well. And the strait through which water comes from the sea is 200 km wide. True, people with their restless and ill-considered activities almost destroyed Kara-Bogaz-Gol. They fenced off the lagoon with a dam, and its level plummeted. But after 12 years, the mistake was corrected and the strait was restored.
In the Caspian at all times there was developed shipping... In the Middle Ages, merchants carried exotic spices and skins of snow leopards from Persia to Russia by sea. Today, the reservoir connects the cities located on its banks. Ferry crossings are practiced. There is a water connection with the Black and Baltic Seas through rivers and canals.
Caspian Sea on the map
The reservoir is also important from the point of view fishing, because sturgeon lives in it in large numbers and gives caviar. But today the number of sturgeon has significantly decreased. Environmentalists propose to ban the capture of this valuable fish until the population recovers. But this issue has not yet been resolved. The number of tuna, bream, and pike perch also decreased. Here it is necessary to take into account the fact that poaching is highly developed at sea. The reason for it is the difficult economic situation in the region.
And, of course, I need to say a few words about oil... The mining of "black gold" at sea began in 1873. The districts adjacent to Baku have become a real gold mine. There were more than 2 thousand wells here, and oil production and processing was carried out on an industrial scale. At the beginning of the 20th century, it was the center of the international oil industry. In 1920, Azerbaijan was captured by the Bolsheviks. Oil wells and factories were requisitioned. The entire oil industry came under the control of the USSR. In 1941, Azerbaijan supplied 72% of all oil produced in the socialist state.
In 1994, the "Contract of the Century" was signed. He laid the foundation for the international development of the Baku oil fields. The main Baku-Tbilisi-Ceyhan pipeline allows Azerbaijani oil to flow directly to the Mediterranean port of Ceyhan. It was put into operation in 2006. Today, oil reserves are estimated at 12 trillion. US dollars.
Thus, it can be seen that the Caspian Sea is one of the most important economic regions in the world. The political situation in the Caspian region is rather complicated. For a long time, there were disputes about the maritime borders between Azerbaijan, Turkmenistan and Iran. There were many inconsistencies, disagreements, which negatively affected the development of the region.
This was ended on August 12, 2018. On this day, the states of the "Caspian Five" signed the Convention on the Legal Status of the Caspian Sea. This document delimited the bottom and subsoil, and each of the five countries (Russia, Kazakhstan, Iran, Turkmenistan, Azerbaijan) received its share in the Caspian basin. The rules for the implementation of shipping, fishing, scientific research, and the laying of pipelines were also approved. The boundaries of territorial waters received the status of state ones.
Yuri Syromyatnikov
Caspian Sea is inland and is located in an extensive mainland depression on the border of Europe and Asia. The Caspian Sea has no connection with the ocean, which formally allows us to call it a lake, but it has all the features of the sea, since in past geological eras it had connections with the ocean.
Today Russia has access only to the North Caspian and the Dagestan part of the western coast of the Middle Caspian. The waters of the Caspian Sea wash the shores of countries such as Azerbaijan, Iran, Turkmenistan, Kazakhstan.
The sea area is 386.4 thousand km2, the volume of water is 78 thousand m3.
The Caspian Sea has a vast drainage basin, with an area of about 3.5 million km2. The nature of the landscapes, climatic conditions and types of rivers are different. Despite the vastness of the drainage basin, only 62.6% of its area is in wastewater areas; about 26.1% - for closed drainage. The area of the Caspian Sea itself is 11.3%. 130 rivers flow into it, but almost all of them are located in the north and west (and the eastern bank does not have a single river reaching the sea at all). The largest river in the Caspian basin is the Volga, which provides 78% of the river waters entering the sea (it should be noted that more than 25% of Russia's economy is located in the basin of this river, and this undoubtedly determines many hydrochemical and other features of the Caspian Sea waters), as well as rivers Kura, Zhaiyk (Ural), Terek, Sulak, Samur.
Physically and geographically and by the nature of the underwater relief, the sea is divided into three parts: northern, middle and southern. The conditional border between the northern and middle parts runs along the line of the Chechen island - the Tyub-Karagan cape, between the middle and the south - along the line of the Zhiloy island - Kuuli cape.
The shelf of the Caspian Sea is, on average, limited to a depth of about 100 m. The continental slope, which begins below the edge of the shelf, ends in the middle part at a depth of 500–600 m, in the southern part, where it is very steep, at 700–750 m.
The northern part of the sea is shallow, its average depth is 5–6 m, maximum depths of 15–20 m are located on the border with the middle part of the sea. The bottom relief is complicated by the presence of banks, islands, grooves.
The middle part of the sea is a separate basin, the area of maximum depths of which - the Derbent depression - is shifted to the western coast. The average depth of this part of the sea is 190 m, the greatest is 788 m.
The southern part of the sea is separated from the middle Apsheron sill, which is a continuation of the Greater Caucasus. The depths above this underwater ridge do not exceed 180 m. The deepest part of the South Caspian depression with a maximum depth of 1025 m for the sea is located east of the Kura delta. Several underwater ridges up to 500 m high rise above the bottom of the basin.
The shores The Caspian Sea is diverse. In the northern part of the sea, they are quite indented. Here are the Kizlyarsky, Agrakhansky, Mangyshlaksky bays and many shallow bays. Notable peninsulas: Agrakhansky, Buzachi, Tyub-Karagan, Mangyshlak. Large islands in the northern part of the sea - Tyuleniy, Kulaly. In the deltas of the Volga and Ural rivers, the coastline is complicated by many islets and channels, which often change their position. Many small islands and banks are located on other parts of the coastline.
The middle part of the sea has a relatively flat coastline. On the western coast, on the border with the southern part of the sea, the Absheron Peninsula is located. To the east of it, the islands and banks of the Absheron archipelago stand out, of which the largest is Zhiloy Island. The eastern coast of the Middle Caspian is more indented, here the Kazakh Gulf with Kenderli Bay and several capes stand out. The largest bay on this coast is Kara-Bogaz-Gol.
The islands of the Baku archipelago are located to the south of the Absheron Peninsula. The origin of these islands, as well as some banks off the eastern coast of the southern part of the sea, is associated with the activity of underwater mud volcanoes lying on the bottom of the sea. On the eastern coast there are large bays of Turkmenbashy and Turkmensky, and near the island of Ogurchinsky.
One of the most striking phenomena of the Caspian is the periodic variability of its level. In historical time, the Caspian Sea had a level lower than the World Ocean. Fluctuations in the level of the Caspian Sea are so great that for more than a century they have attracted the attention of not only scientists. Its peculiarity is that in the memory of mankind its level has always been below the level of the World Ocean. Since the beginning of instrumental observations (since 1830) over the sea level, the amplitude of its fluctuations was almost 4 m, from –25.3 m in the eighties of the XIX century. to –29 m in 1977. In the last century, the level of the Caspian Sea changed significantly twice. In 1929, it stood at about –26 m, and since it had been close to this mark for almost a century, this level position was considered as mean annual or secular. In 1930, the level began to decline rapidly. By 1941, it had dropped by almost 2 m. This led to the drying up of vast coastal bottom areas. The decrease in the level, with its small fluctuations (short-term insignificant rises in the level in 1946-1948 and 1956-1958), continued until 1977 and reached -29.02 m, that is, the level took the lowest position in the last 200 years.
In 1978, contrary to all forecasts, the sea level began to rise. As of 1994, the level of the Caspian Sea was at –26.5 m, that is, in 16 years the level rose by more than 2 m. The rate of this rise is 15 cm per year. The increase in the level in some years was higher, and in 1991 it reached 39 cm.
The general fluctuations in the level of the Caspian Sea are superimposed on its seasonal changes, the mean multiyear of which reaches 40 cm, as well as on surges. The latter are especially pronounced in the Northern Caspian. The northwestern coast is characterized by large surges created by the prevailing storms of the eastern and southeastern directions, especially during the cold period of the year. A number of large (more than 1.5–3 m) surges have been observed here over the past decades. An especially large surge with catastrophic consequences was noted in 1952. Fluctuations in the level of the Caspian Sea cause great damage to the states surrounding its water area.
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Climate. The Caspian Sea is located in temperate and subtropical climatic zones. Climatic conditions change in the meridional direction, since from north to south the sea stretches for almost 1200 km.
In the Caspian region, various systems of atmospheric circulation interact, however, during the year, the winds of the eastern points prevail (the influence of the Asian maximum). The position in rather low latitudes provides a positive balance of heat inflow, therefore the Caspian Sea serves as a source of heat and moisture for the passing air masses for most of the year. The average annual air temperature in the northern part of the sea is 8–10 ° С, in the middle - 11–14 ° С, in the southern part - 15–17 ° С. However, in the northernmost regions of the sea, the average January temperature is from –7 to –10 ° С, and the minimum during the invasions of the Arctic air is up to –30 ° С, which determines the formation of the ice cover. In summer, the entire region under consideration is dominated by rather high temperatures - 24–26 ° С. Thus, the North Caspian is subject to the sharpest temperature fluctuations.
The Caspian Sea is characterized by a very small amount of precipitation falling per year - only 180 mm, and most of it falls on the cold season of the year (from October to March). However, the North Caspian Sea differs in this respect from the rest of the basin: here the average annual precipitation is less (for the western part, only 137 mm), and the distribution over the seasons is more even (10–18 mm per month). In general, we can talk about the proximity of climatic conditions to arid ones.
Water temperature. Distinctive features of the Caspian Sea (large differences in depths in different parts of the sea, the nature of the bottom topography, isolation) have a certain impact on the formation of temperature conditions. In the shallow North Caspian, the entire water column can be regarded as homogeneous (the same applies to shallow bays located in other parts of the sea). In the Middle and South Caspian, surface and deep masses can be distinguished, separated by a transitional layer. In the North Caspian and in the surface layers of the Middle and South Caspian, the water temperature varies over a wide range. In winter, temperatures change from north to south from less than 2 to 10 ° С, the water temperature near the western coast is 1–2 ° С higher than that of the east, in the open sea the temperature is higher than at the coasts: by 2–3 ° С in the middle part and by 3–4 ° С in the southern part of the sea. In winter, the temperature distribution is more uniform with depth, which is facilitated by the winter vertical circulation. During moderate and severe winters in the northern part of the sea and shallow bays on the east coast, the water temperature drops to freezing point.
In summer, the temperature changes in space from 20 to 28 ° C. The highest temperatures are observed in the southern part of the sea; temperatures are also quite high in the well-warmed shallow North Caspian. The zone of distribution of the lowest temperatures is adjacent to the eastern coast. This is due to the rise to the surface of cold deep waters. Temperatures are also relatively low in the poorly warmed deep-water central part. In the open areas of the sea, in late May – early June, a layer of temperature jump begins, which is most pronounced in August. Most often, it is located between the horizons of 20 and 30 m in the middle part of the sea and 30 and 40 m in the southern part. In the middle part of the sea, due to the drive off the east coast, the shock layer rises close to the surface. In the bottom layers of the sea, the temperature throughout the year is about 4.5 ° C in the middle and 5.8–5.9 ° C in the southern part.
Salinity. Salinity values are determined by such factors as river runoff, water dynamics, which mainly includes wind and gradient currents, the resulting water exchange between the western and eastern parts of the North Caspian and between the North and Middle Caspian, bottom topography, which determines the location of waters with different salinity, mainly along the isobaths, evaporation, providing a shortage of fresh water and the inflow of more saline ones. These factors collectively affect seasonal differences in salinity.
The North Caspian can be considered as a reservoir of constant mixing of river and Caspian waters. The most active mixing occurs in the western part, where both river and Middle Caspian waters directly flow. In this case, the horizontal salinity gradients can reach 1 ‰ per 1 km.
The eastern part of the North Caspian is characterized by a more uniform salinity field, since most of the river and sea (Middle Caspian) waters enter this sea area in a transformed form.
According to the values of the horizontal salinity gradients, it is possible to distinguish in the western part of the North Caspian a river-sea contact zone with water salinity from 2 to 10 ‰, in the eastern part from 2 to 6 ‰.
Significant vertical salinity gradients in the Northern Caspian are formed as a result of the interaction of river and sea waters, with runoff playing a decisive role. The intensification of vertical stratification is also facilitated by the unequal thermal state of the water layers, since the temperature of the surface desalinated water arriving in summer from the seaside is 10–15 ° C higher than that of the bottom water.
In the deep-water basins of the Middle and South Caspian, salinity fluctuations in the upper layer are 1–1.5 ‰. The largest difference between the maximum and minimum salinity was noted in the Apsheron sill area, where it is 1.6 ‰ in the surface layer and 2.1 ‰ at the 5 m horizon.
The decrease in salinity along the western coast of the South Caspian in the 0–20 m layer is caused by the Kura river runoff. The influence of the Kura runoff decreases with depth; at the horizons of 40–70 m, the range of salinity fluctuations is no more than 1.1 ‰. Along the entire western coast to the Absheron Peninsula, there is a strip of desalinated waters with a salinity of 10–12.5 ‰ coming from the North Caspian.
In addition, in the South Caspian, an increase in salinity occurs when saline waters are carried out from bays and bays on the eastern shelf under the influence of southeastern winds. Subsequently, these waters are transferred to the Middle Caspian.
In the deep layers of the Middle and South Caspian, salinity is about 13 ‰. In the central part of the Middle Caspian, such salinity is observed at horizons below 100 m, and in the deep-water part of the South Caspian, the upper boundary of waters with increased salinity drops to 250 m. It is obvious that in these parts of the sea, vertical mixing of waters is difficult.
Surface water circulation. The currents in the sea are mainly wind-driven. In the western part of the Northern Caspian, the currents of the western and eastern quarters are most often observed, in the eastern part, the southwestern and southern ones. The currents caused by the runoff of the Volga and Ural rivers are traced only within the estuarine seashore. The prevailing velocities of currents are 10–15 cm / s, in the open regions of the Northern Caspian the maximum velocities are about 30 cm / s.
In the coastal areas of the middle and southern parts of the sea, in accordance with the wind directions, currents of the north-west, north, south-east and south directions are observed, along the east coast currents of the east direction often take place. Along the western coast of the middle part of the sea, the most stable currents are southeastern and southern. The velocities of the currents are on average about 20–40 cm / s, the maximum ones reach 50–80 cm / s. Other types of currents also play a significant role in the circulation of sea waters: gradient, seiche, inertial.
Ice formation. The North Caspian is covered with ice annually in November, the area of the freezing part of the water area depends on the severity of winter: in severe winters, the entire North Caspian is covered with ice, in soft ice it is kept within the 2-3 meter isobath. The appearance of ice in the middle and southern parts of the sea occurs in December-January. On the east coast, ice is of local origin, on the west coast - most often brought from the northern part of the sea. In severe winters near the eastern coast of the middle part of the sea, shallow bays freeze, near the coast, coastlines and fast ice form, near the western coast, drifting ice in abnormally cold winters extends to the Absheron Peninsula. The disappearance of the ice cover is observed in the second half of February – March.
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Oxygen content. The spatial distribution of dissolved oxygen in the Caspian Sea has a number of regularities. The central part of the Northern Caspian is characterized by a fairly uniform oxygen distribution. An increased oxygen content is found in the areas of the pre-estuarine seaside of the Volga River, a lower one - in the southwestern part of the North Caspian. In the Middle and South Caspian, the highest oxygen concentrations are confined to coastal shallow areas and pre-estuarine coastal areas of rivers, with the exception of the most polluted areas of the sea (Baku Bay, Sumgait region, etc.). In summer, due to significant heating of water masses and activation of photosynthesis processes, the leading factors in the formation of oxygen regime in surface waters are photosynthetic processes, in bottom waters - biochemical oxygen consumption by bottom sediments. Due to the high temperature of the waters, stratification of the water column, a large inflow of organic matter and its intense oxidation, oxygen is rapidly consumed with minimal input to the lower layers of the sea, as a result of which an oxygen deficiency zone forms in the North Caspian. Intensive photosynthesis in open waters of deep-water areas of the Middle and South Caspian covers the upper 25-meter layer, where oxygen saturation is more than 120%. |
- The North Caspian, which is a vast area of mixing of river and sea waters, is characterized by significant spatial gradients in the distribution of nutrients;
- in the Middle Caspian, the cyclonic nature of the circulation contributes to the rise of deep waters with a high content of nutrients into the overlying layers of the sea;
- in the deep-water areas of the Middle and South Caspian, the vertical distribution of nutrients depends on the intensity of the convective mixing process, and their content increases with depth.
On the dynamics of concentrations nutrients During the year, the Caspian Sea is influenced by such factors as seasonal fluctuations of biogenic runoff in the sea, seasonal ratio of production and destruction processes, the intensity of exchange between soil and water mass, ice conditions in winter in the North Caspian, processes of winter vertical circulation in deep-water areas seas.
In winter, a significant water area of the North Caspian is covered with ice, but biochemical processes are actively developing in sub-ice water and in ice. The ice of the North Caspian, being a kind of accumulator of nutrients, transforms these substances entering the sea with river runoff and from the atmosphere.
As a result of the winter vertical circulation of waters in the deep-water regions of the Middle and South Caspian in the cold season, the active layer of the sea is enriched with nutrients due to their supply from the underlying layers.
Spring for the waters of the Northern Caspian is characterized by a minimum content of phosphates, nitrites and silicon, which is explained by the spring outbreak of phytoplankton development (silicon is actively consumed by diatoms). The high concentrations of ammonium and nitrate nitrogen, characteristic of the waters of a significant water area of the North Caspian during floods, are due to intensive washing by the river waters of the Volga delta.
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In the spring season, in the area of water exchange between the North and Middle Caspian in the subsurface layer, at the maximum oxygen content, the phosphate content is minimal, which, in turn, indicates the activation of the photosynthesis process in this layer.
In the South Caspian, the distribution of nutrients in spring is basically similar to their distribution in the Middle Caspian.
In the summertime, redistribution of various forms of biogenic compounds is found in the waters of the Northern Caspian. Here, the content of ammonium nitrogen and nitrates significantly decreases, at the same time there is a slight increase in the concentration of phosphates and nitrites and a rather significant increase in the concentration of silicon. In the Middle and South Caspian, the concentration of phosphates decreased due to their consumption in the process of photosynthesis and the difficulty of water exchange with the deep-water accumulation zone.
In autumn in the Caspian Sea, due to the cessation of the activity of some phytoplankton species, the content of phosphates and nitrates increases, while the concentration of silicon decreases, as there is an autumn outbreak of the development of diatoms.
More than 150 years on the shelf of the Caspian Sea oil.
Currently, large reserves of hydrocarbons are being developed on the Russian shelf, the resources of which on the Dagestan shelf are estimated at 425 million tons of oil equivalent (of which 132 million tons of oil and 78 billion cubic meters of gas), on the shelf of the North Caspian - 1 billion tons of oil ...
A total of about 2 billion tons of oil have already been produced in the Caspian Sea.
Losses of oil and products of its processing during extraction, transportation and use reach 2% of the total volume.
Main sources of income pollutants, including oil products, into the Caspian Sea - this is the outflow with river runoff, the discharge of untreated industrial and agricultural wastewater, municipal wastewater from cities and towns located on the coast, shipping, exploration and exploitation of oil and gas fields located at the bottom of the sea, transportation of oil by sea. Places of entry of pollutants with river runoff are 90% concentrated in the North Caspian, industrial effluents are mainly confined to the area of the Absheron Peninsula, and increased oil pollution of the South Caspian is associated with oil production and oil exploration drilling, as well as with active volcanic activity (mud volcanism) in the zone of oil and gas structures.
From the territory of Russia, about 55 thousand tons of oil products are annually supplied to the North Caspian, including 35 thousand tons (65%) from the Volga River and 130 tons (2.5%) from the Terek and Sulak rivers.
Thickening of the film on the water surface up to 0.01 mm disrupts the processes of gas exchange, threatens the death of the hydrobiota. Toxic for fish is the concentration of oil products 0.01 mg / l, for phytoplankton - 0.1 mg / l.
The development of oil and gas resources of the bottom of the Caspian Sea, the projected reserves of which are estimated at 12-15 billion tons of standard fuel, in the coming decades will become the main factor of anthropogenic pressure on the ecosystem of the sea.
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Caspian autochthonous fauna. The total number of autochthons is 513 species or 43.8% of the entire fauna, which include herring, gobies, molluscs, etc.
Arctic species. The total number of the Arctic group is 14 species and subspecies, or only 1.2% of the entire fauna of the Caspian Sea (mysids, sea cockroach, white fish, Caspian salmon, Caspian seal, etc.). The basis of the Arctic fauna is made up of crustaceans (71.4%), which easily tolerate desalination and live at great depths in the Middle and South Caspian (from 200 to 700 m), since the lowest water temperatures are maintained here throughout the year (4.9– 5.9 ° C).
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Mediterranean views. These are 2 types of mollusks, needle-fish, etc. At the beginning of the 20s of our century, the mithielastr mollusk penetrated here, later 2 types of shrimp (with mullet, when acclimatized), 2 types of mullet and flounder. Some Mediterranean species entered the Caspian after the opening of the Volga-Don Canal. Mediterranean species play an essential role in the food supply for fish in the Caspian Sea.
Freshwater fauna(228 species). This group includes anadromous and semi-anadromous fish (sturgeon, salmon, pike, catfish, carp, as well as rotifers).
Marine species. These are ciliates (386 forms), 2 types of foraminifera. There are especially many endemics among higher crustaceans (31 species), gastropods (74 species and subspecies), bivalve molluscs (28 species and subspecies) and fish (63 species and subspecies). The abundance of endemics in the Caspian Sea makes it one of the most original brackish water bodies of the planet.
The Caspian Sea provides over 80% of the world's sturgeon catches, the bulk of which is in the North Caspian.
To increase catches of sturgeon, which sharply decreased during the years of falling sea level, a set of measures is being carried out. Among them is a complete ban on fishing for sturgeon in the sea and its regulation in rivers, an increase in the scale of factory sturgeon breeding.
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Caspian Sea- the largest lake on Earth, located at the junction of Europe and Asia, called the sea because of its size. Caspian Sea is a closed lake, and the water in it is salty, from 0.05% near the mouth of the Volga to 11-13% in the southeast.
The water level is subject to fluctuations, currently - about 28 m below the level of the World Ocean.
Square Caspian Sea at present, it is about 371,000 sq km, the maximum depth is 1025 m.
Length of coastline Caspian Sea estimated at about 6,500 - 6,700 kilometers, with islands up to 7,000 kilometers. The shores Caspian Sea most of its territory is low and smooth. In the northern part, the coastline is cut by water channels and islands of the Volga and Ural deltas, the shores are low and swampy, and the water surface is covered with thickets in many places. The eastern 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 Bay and Kara-Bogaz-Gol.
V Caspian Sea 130 rivers flow into the river, 9 of which have delta-shaped estuaries. Large rivers flowing into the Caspian Sea are Volga, Terek (Russia), Ural, Emba (Kazakhstan), Kura (Azerbaijan), Samur (Russian border with Azerbaijan), Atrek (Turkmenistan) and others.
Caspian Sea Map
The Caspian Sea washes the shores of five coastal states:
Russia (Dagestan, Kalmykia and the Astrakhan region) - in the west and north-west, the length of the coastline is 695 kilometers
Kazakhstan - in the north, north-east and east, the length of the coastline is 2320 kilometers
Turkmenistan - in the southeast, the length of the coastline is 1200 kilometers
Iran - in the south, the length of the coastline is 724 kilometers
Azerbaijan - in the south-west, the length of the coastline is 955 kilometers
Water temperature
subject to significant latitudinal changes, most pronounced in winter, when the temperature varies from 0 - 0.5 ° C at the ice edge in the north of the sea to 10 - 11 ° C in the south, that is, the difference in water temperature is about 10 ° C. For shallow areas with depths less than 25 m, the annual amplitude can reach 25 - 26 ° C. On average, the water temperature near the western coast is 1 - 2 ° C higher than that of the eastern one, and in the open sea the water temperature is 2 - 4 ° C higher than that of the coasts.
Climate of the Caspian Sea- 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 is 44 degrees.
Animal world
The fauna of the Caspian Sea is represented by 1809 species, of which 415 are vertebrates. V Caspian Sea 101 species of fish have been registered, and most of the world's stocks of sturgeon, as well as freshwater fish such as roach, carp, and pike perch, are concentrated there. Caspian Sea- habitat of such fish as carp, mullet, sprat, kutum, bream, salmon, perch, pike. V Caspian Sea there is also a marine mammal - the Caspian seal.
Vegetable world
Vegetable world Caspian Sea and its coastline is represented by 728 species. From plants to Caspian Sea predominantly algae - blue-green, diatoms, red, brown, charovy and others, from flowering - zostera and ruppia. By origin, the flora belongs mainly to the Neogene age, however, some plants were introduced into Caspian Sea a person knowingly or on the bottoms of ships.
Oil and gas
V Caspian Sea many oil and gas fields are being developed. Proven oil resources in Caspian Sea are about 10 billion tons, the total resources of oil and gas condensate are estimated at 18 - 20 billion tons.
Oil production in Caspian Sea began in 1820, when the first oil well was drilled on the Absheron shelf. In the second half of the 19th century, oil production began in industrial volumes on the Apsheron Peninsula, then in other territories.
In addition to oil and gas production, on the coast Caspian Sea and the Caspian shelf is also mining salt, limestone, stone, sand, clay.
Ecological problems
Ecological problems Caspian Sea associated with water pollution as a result of oil production and transportation on the continental shelf, the influx of pollutants from the Volga and other rivers flowing into Caspian Sea, the vital activity of coastal cities, as well as the flooding of certain objects due to an increase in the level Caspian Sea... Predatory hunting 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.
The territory of Russia is washed by twelve seas belonging to the basins of three oceans. But one of these seas - the Caspian - is often called a lake, which sometimes perplexes people who are poorly versed in geography.
Meanwhile, it is really more correct to call the Caspian a lake, not a sea. Why? Let's figure it out.
A bit of geography. Where is the Caspian Sea located?
Covering an area of over 370,000 square kilometers, the Caspian Sea stretches from north to south, dividing the expanses of Europe and Asia with its water surface. Its coastline belongs to five different countries: Russia, Kazakhstan, Azerbaijan, Turkmenistan and Iran. Geographers conditionally divide its water area into three parts: the Northern (25% of the area), the Middle (36% of the area) and the South Caspian (39% of the area), which differ in climate, geological setting and natural features. The coastline is mostly flat, cut by river channels, covered with vegetation, and in the northern part, where the Volga flows into the Caspian, it is also swampy.
The Caspian Sea has about 50 large and small islands, about a dozen bays and six large peninsulas. In addition to the Volga, about 130 rivers flow into it, and nine rivers form fairly wide and branched deltas. The annual drain of the Volga is about 120 cubic kilometers. Together with other large rivers - Terek, Ural, Emba and Sulak - this accounts for up to 90% of the total annual runoff into the Caspian.
Why is the Caspian called a lake?
The main feature of any sea is the presence of straits connecting it to the ocean. The Caspian Sea is a closed or closed body of water that receives river water, but does not connect to any ocean. 
Its water contains a very small amount of salt compared to other seas (about 0.05%) and is considered slightly salty. Due to the absence of at least one strait connecting to the ocean, the Caspian is often called the largest lake in the world, since the lake is a completely closed body of water, which is fed only by river water.
International maritime laws do not apply to the waters of the Caspian, and its water area is divided among all the countries that adjoin it, in proportion to the coastline.
Why is the Caspian called the sea?
Despite all of the above, most often in geography, as well as in international and domestic documents, the name "Caspian Sea" is used, and not "Caspian Lake". First of all, this is due to the size of the reservoir, which is much more typical for the sea than for the lake. Even, which is much smaller in area than the Caspian Sea, locals often call it the sea. There are no other lakes in the world whose shores belong simultaneously to five different countries.
In addition, attention should be paid to the bottom structure, which has a pronounced oceanic type near the Caspian Sea. Once the Caspian Sea, most likely, was connected with the Mediterranean, but tectonic processes and drying up separated it from the World Ocean. More than fifty islands are located in the Caspian Sea, and some of them are large enough, even by international standards, they are considered large. All this makes it possible to call the Caspian a sea, not a lake.
origin of name
Why is this sea (or lake) called the Caspian? The origin of any name is often associated with the ancient history of the area. Different peoples living on the shores of the Caspian called it differently. More than seventy names of this reservoir have survived in history - it was called the Hyrkan, Derbent, Sarai Sea, etc. 
Iranians and Azerbaijanis still call it the Khazar Sea. It began to be called Caspian by the name of the ancient tribe of nomadic horse breeders who lived in the steppes adjacent to its coast - the numerous tribe of the Caspians. They gave the name to the largest lake on our planet - the Caspian Sea.
