Countries surrounding the Caspian Sea. Caspian Sea: description, depth, width, interesting facts
Caspian Sea is inland and located in a vast continental depression on the border of Europe and Asia. The Caspian Sea has no connection with the ocean, which formally allows it to be called a lake, but it has all the features of the sea, since it had connections with the ocean in past geological epochs.
Today Russia has access only to the Northern Caspian and the Dagestan part west coast Middle Caspian. The waters of the Caspian Sea wash the shores of such countries as Azerbaijan, Iran, Turkmenistan, Kazakhstan.
The area of the sea 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. nature of landscapes, climatic conditions and the types of rivers are different. Despite the vastness of the drainage basin, only 62.6% of its area falls on waste areas; about 26.1% - for drainless. 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 coast does not have a single river reaching the sea at all). largest river the Caspian basin - the Volga, which provides 78% of the river water entering the sea (it should be noted that more than 25% of the Russian economy is located in the basin of this river, and this undoubtedly determines many hydrochemical and other features of the waters of the Caspian Sea), as well as the Kura River, Zhaiyk (Ural), Terek, Sulak, Samur.
In physical and geographical terms and according to the nature of the underwater relief, the sea is divided into three parts: northern, middle and southern. The conditional boundary between the northern and middle parts runs along the line of Chechen Island–Cape Tyub-Karagan, between the middle and southern parts - along the line of Zhiloy Island–Cape Kuuli.
The shelf of the Caspian Sea, on average, is limited to depths of about 100 m. The continental slope, which begins below the edge of the shelf, ends in the middle part at about 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, the 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, furrows.
The middle part of the sea is a separate basin, the region 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 part by the Apsheron threshold, which is a continuation of the Greater Caucasus. Depths above this underwater ridge do not exceed 180 m. The deepest part of the South Caspian basin with a maximum sea depth of 1025 m is located east of the Kura delta. Several underwater ridges up to 500 m high rise above the bottom of the basin.
coast The Caspian Sea are diverse. In the northern part of the sea, they are quite strongly indented. Here are the bays of Kizlyar, Agrakhan, Mangyshlak and many shallow bays. Notable peninsulas: Agrakhansky, Buzachi, Tyub-Karagan, Mangyshlak. Large islands in the northern part of the sea are 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. A lot of small islands and cans 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 Apsheron Peninsula is located. To the east of it, the islands and banks of the Apsheron archipelago stand out, of which the most large island Residential. The eastern shore of the Middle Caspian is more indented, the Kazakh Bay stands out here with the Kenderli Bay and several capes. The largest bay of this coast is Kara-Bogaz-Gol.
South of the Absheron Peninsula are the islands of the Baku archipelago. The origin of these islands, as well as some of the jars east coast the southern part of the sea is associated with the activity of underwater mud volcanoes lying at the bottom of the sea. On the eastern shore are the large bays of Turkmenbashi and Turkmensky, and near it is the island of Ogurchinsky.
One of the most striking phenomena of the Caspian Sea is the periodic variability of its level. AT historical time The Caspian Sea had a lower level 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) of the sea level, the amplitude of its fluctuations has been 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 has changed significantly twice. In 1929 it stood at a mark of about -26 m, and since it had been close to this mark for almost a century, this position of the level was considered as a long-term or secular average. In 1930, the level began to decline rapidly. Already by 1941, it had dropped by almost 2 m. This led to the drying up of vast coastal areas of the bottom. 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 the mark of -29.02 m, i.e., the level took the lowest position for 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 has risen by more than 2 m. The rate of this rise is 15 cm per year. The level increment in some years was higher, and in 1991 it reached 39 cm.
The general fluctuations in the level of the Caspian Sea are superimposed by its seasonal changes, the average long-term of which reaches 40 cm, as well as surge phenomena. The latter are especially pronounced in the Northern Caspian. The northwestern coast is characterized by large surges created by the prevailing, especially in the cold season, storms of eastern and southeastern directions. Over the past decades, a number of large (more than 1.5–3 m) surges have been observed here. A particularly 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 the temperate and subtropical climatic zones. Climatic conditions change in the meridional direction, since the sea stretches for almost 1200 km from north to south.
In the Caspian region, various systems of atmospheric circulation interact, however, during the year, easterly winds prevail (the influence of the Asian maximum). The position at rather low latitudes provides a positive balance of heat inflow, so the Caspian Sea serves as a source of heat and moisture for 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 part - 11–14°С, in the southern part – 15–17°С. However, in the northernmost parts of the sea, the average January temperature is from –7 to –10°C, and the minimum temperature during arctic air intrusions is up to –30°C, which determines the formation of the ice cover. In summer, rather high temperatures dominate over the entire region under consideration - 24–26°C. Thus, the Northern Caspian is subject to the most sharp temperature fluctuations.
The Caspian Sea is characterized by a very small amount of precipitation per year - only 180 mm, and most of it falls on the cold season of the year (from October to March). However, the Northern Caspian differs in this respect from the rest of the basin: here the average annual precipitation is less (only 137 mm for the western part), 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. The distinctive features of the Caspian Sea (great differences in depths in different parts of the sea, the nature of the bottom relief, isolation) have a certain influence on the formation of temperature conditions. In the shallow North Caspian, the entire water column can be considered 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 separated by a transitional layer can be distinguished. In the Northern Caspian and in the surface layers of the Middle and Southern Caspian, the water temperature varies over a wide range. In winter, temperatures vary from north to south from less than 2 to 10°С, the water temperature near the western coast is 1–2°С higher than near the eastern one, in the open sea the temperature is higher than near 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.
In summer, the temperature varies 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 east coast. This is due to the rise of cold deep waters to the surface. Temperatures are also relatively low in the poorly heated deep-water central part. In the open areas of the sea, in late May–early June, the formation of a temperature jump layer begins, which is most clearly expressed in August. Most often, it is located between 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 surge near the eastern coast, the shock layer rises close to the surface. In the bottom layers of the sea, the temperature during the year is about 4.5°C in the middle part and 5.8–5.9°C in the south.
Salinity. Salinity values are determined by such factors as river runoff, water dynamics, including mainly wind and gradient currents, the resulting water exchange between the western and eastern parts of the Northern Caspian and between the Northern and Middle Caspian, the bottom topography, which determines the location of waters with different salinity, mainly along the isobaths, evaporation, which ensures the shortage of fresh water and the inflow of more saline ones. These factors collectively affect the seasonal differences in salinity.
The Northern 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 Central Caspian waters directly enter. In this case, horizontal salinity gradients can reach 1‰ per 1 km.
The eastern part of the Northern Caspian is characterized by a more uniform salinity field, since most of the river and sea (Middle Caspian) waters enter this area of the sea in a transformed form.
According to the values of horizontal salinity gradients, in the western part of the Northern Caspian, a river-sea contact zone can be distinguished 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, the runoff plays a decisive role in this case. The intensification of vertical stratification is also facilitated by the unequal thermal state of the water layers, since the temperature of the surface desalinated waters coming from the coast in summer is 10–15°C higher than that of the bottom ones.
In the deep 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 area of the Apsheron threshold, 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 runoff of the Kura River. 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 stretches a strip of desalinated water with a salinity of 10–12.5‰ coming from the Northern Caspian.
In addition, salinity increases in the South Caspian due to the removal of saline waters from bays and inlets on the eastern shelf under the action of southeasterly winds. In the future, 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 part of the South Caspian, the upper boundary of waters with increased salinity drops to 250 m. Obviously, in these parts of the sea vertical mixing water is difficult.
Surface water circulation. Currents in the sea are mainly wind-driven. In the western part of the Northern Caspian, currents of the western and eastern quarters are most often observed, in the eastern - southwestern and southern. The currents caused by the runoff of the Volga and Ural rivers can be traced only within the estuarine coast. The prevailing current velocities are 10–15 cm/s; in the open areas 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 northwestern, northern, southeastern and southern directions, currents often occur off the east coast east direction. Along the western coast of the middle part of the sea, the most stable currents are southeast and south. Current velocities 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 ones.
Ice formation. The Northern Caspian is covered with ice annually in November, the area of the freezing part of the water area depends on the severity of the winter: in severe winters, the entire Northern Caspian is covered with ice, in soft ice it stays within the 2–3 meter isobath. The appearance of ice in the middle and southern parts of the sea falls on December-January. Near the eastern coast, ice is of local origin, near the western coast - most often brought from the northern part of the sea. In severe winters, shallow bays freeze off the eastern coast of the middle part of the sea, coasts and landfast ice form off the coast, and drift ice spreads to the Absheron Peninsula in abnormally cold winters off the western coast. 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 distribution of oxygen. An increased oxygen content is found in the areas of the pre-estuary seashore of the Volga River, a lower one - in the southwestern part of the Northern Caspian. In the Middle and South Caspian, the highest oxygen concentrations are confined to coastal shallow areas and pre-estuary seashores of rivers, with the exception of the most polluted areas of the sea (Baku Bay, Sumgait region, etc.). In summer, due to significant warming of water masses and activation of photosynthesis processes, the leading factors in the formation of the oxygen regime in surface waters are photosynthetic processes, in near-bottom waters - biochemical oxygen consumption by bottom sediments. Thanks to high temperature waters, stratification of the water column, a large influx of organic matter and its intense oxidation, oxygen is quickly consumed with its minimal entry into the lower layers of the sea, as a result of which an oxygen deficiency zone is formed in the Northern Caspian. Intensive photosynthesis in the open waters of the deep-water regions of the Middle and South Caspian covers the upper 25-meter layer, where oxygen saturation is more than 120%. |
- The Northern Caspian, which is a vast mixing zone 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 upwelling 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 process of convective mixing, and their content increases with depth.
On the dynamics of concentrations nutrients during the year in the Caspian Sea are influenced by such factors as seasonal fluctuations in the biogenic runoff into the sea, the seasonal ratio of production-destruction processes, the intensity of the exchange between soil and water mass, ice conditions in winter time in the Northern Caspian, the processes of winter vertical circulation in the deep sea areas.
In winter, a significant area of the Northern Caspian is covered with ice, but biochemical processes are actively developing in the under-ice water and ice. The ice of the Northern Caspian, being a kind of accumulator of biogenic substances, transforms these substances that enter the sea with river runoff and from the atmosphere.
As a result of the winter vertical circulation of waters in the deep-sea regions of the Middle and Southern 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 North 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). High concentrations of ammonium and nitrate nitrogen, characteristic of the waters of a large area of the Northern Caspian during floods, are due to intensive flushing of the Volga delta by river waters.
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In the spring season, in the area of water exchange between the Northern and Middle Caspian in the subsurface layer, with the maximum oxygen content, the content of phosphates 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 summer, a redistribution of water is found in the waters of the Northern Caspian various forms biogenic compounds. Here, the content of ammonium nitrogen and nitrates significantly decreases, while at the same time there is a slight increase in the concentrations of phosphates and nitrites and a rather significant increase in the concentration of silicon. In the Middle and South Caspian, the concentration of phosphates has 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 types of phytoplankton, the content of phosphates and nitrates increases, and the concentration of silicon decreases, as an autumn outbreak of diatoms occurs.
For more than 150 years, oil has been mined 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 m3 of gas), on the shelf of the Northern Caspian - 1 billion tons of oil .
In total, about 2 billion tons of oil have already been produced in the Caspian.
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 removal with river runoff, the discharge of untreated industrial and agricultural effluents, domestic 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. 90% of pollutants with river runoff are concentrated in the Northern Caspian, industrial effluents are confined mainly to the area of the Apsheron Peninsula, and increased oil pollution of the Southern Caspian is associated with oil production and oil exploration drilling, as well as active volcanic activity (mud volcanism) in the zone of oil and gas bearing structures.
From the territory of Russia, about 55 thousand tons of oil products enter the Northern Caspian every year, including 35 thousand tons (65%) from the Volga River and 130 tons (2.5%) from the Terek and Sulak rivers.
The thickening of the film on the water surface up to 0.01 mm disrupts the processes of gas exchange and threatens the death of 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 estimated reserves of which are estimated at 12–15 billion tons of standard fuel, will become the main factor in the anthropogenic load on the ecosystem of the sea in the coming decades.
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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, mollusks, etc.
arctic views. The total number of the Arctic group is 14 species and subspecies, or only 1.2% of the entire fauna of the Caspian (mysids, sea cockroach, white salmon, Caspian salmon, Caspian seal, etc.). The basis of the Arctic fauna is crustaceans (71.4%), which easily tolerate desalination and live at great depths of the Middle and South Caspian (from 200 to 700 m), since the lowest water temperatures (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 mollusk mitilyastra penetrated here, later 2 types of shrimp (with mullets, during their acclimatization), 2 types of mullet and flounder. Some Mediterranean species entered the Caspian after the opening of the Volga-Don Canal. Mediterranean species play a significant role in the fish food base of the Caspian Sea.
freshwater fauna(228 species). This group includes anadromous and semi-anadromous fish (sturgeon, salmon, pike, catfish, cyprinids, as well as rotifers).
Marine views. These are ciliates (386 forms), 2 species of foraminifera. There are especially many endemics among higher crustaceans (31 species), gastropod molluscs (74 species and subspecies), bivalve mollusks (28 species and subspecies) and fish (63 species and subspecies). The abundance of endemics in the Caspian Sea makes it one of the most unique brackish water bodies on the planet.
The Caspian Sea provides more than 80% of the world's sturgeon catch, most of which falls on the North Caspian.
To increase the catches of sturgeon, which dropped sharply during the years of sea level drop, a set of measures is being implemented. Among them - a complete ban on sturgeon fishing in the sea and its regulation in rivers, an increase in the scale of factory breeding of sturgeons.
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Today in Astrakhan the program of celebrating the Day of the Caspian Sea has begun. Such holidays are also celebrated in the five Caspian states. Although the Caspian in modern conditions requires not so much festive events as respect from all who inhabit its shores and exploit its wealth.
"Caspian News", of course, cannot stand aside, because the attitude to the Caspian Sea is inherent in the very name and ideology of our portal. Our story about a unique reservoir is a kind of offering to the “hero of the occasion”.
The uniqueness of the Caspian lies, first of all, in the fact that it is not a sea at all, but a real drainless lake. The sea should have access to the World Ocean, which the Caspian does not have, on the other hand, it salt Lake has all the signs of the sea, from the tides and ending with real storms, about which sailors say: "He who survived the storm in the Caspian Sea is not afraid of any ocean storms." And the oceanic relief of the bottom is convincing evidence that the Caspian, together with the Black and Azov Seas, originally belonged to a single ancient reservoir, that is, it was part of the World Ocean.
Where it is now Caspian lake, several tens of thousands of years ago, a depression formed in the earth's crust. Today it is filled with the waters of the Caspian Sea. At the end of the 20th century, the water level in the Caspian Sea was 28 meters below the level of the World Ocean. Approximately six thousand years ago, the waters of the Caspian gained independence, parting with the World Ocean. Another feature that distinguishes the Caspian from the sea is that the salinity of the water in it is almost three times lower than the salinity of the sea. This is because the rivers carry their fresh waters to the Caspian Sea. The Volga accounts for the largest contribution: it gives the sea-lake almost 80% of all water. And it also connects the Caspian Sea with the World Ocean through a system of canals. That is why this lake is still considered the sea!
In terms of its area and volume of water, the Caspian Sea-Lake has no equal on Earth. The volume of Caspian water is 44% of the reserve of all lake waters of the planet! If we talk about the depth of reservoirs, their area and volume of water, then the lake can compete with the Yellow, Baltic and Black Seas and surpasses the Aegean and Adriatic Seas in the same parameters.
Not every sea can boast that in its history it had as many names as the Caspian: as many as seventy! Each traveler, each expedition to the Caspian Sea and the ancient peoples inhabiting its coast gave it their names. The most famous names are: Dzhurdzhansky, Khvalynsky, Shirvansky, Derbentsky, Saraysky and finally, Khazarsky. In Azerbaijan and Iran, the Caspian Sea is still called the Khazar Sea. And the sea got its modern name because of the tribes of Caspian horse breeders, who for a very long time inhabited the eastern parts of the Caucasus and the steppes of the Caspian territories.
The Caspian Sea is the hero of many legends and traditions in the epic of all peoples living on its shores. Legends, as a rule, tell about the love of the mighty and beautiful hero of the Caspian Sea for one of the beauties named Volga, Kura or Amu-Darya - the choice is huge, since about 130 large and small rivers flow into the sea, nine of which have a mouth in the form deltas. Fantasy on the theme of love is about the same for everyone.
The water area of the sea is divided into three regions: the North, Middle and South Caspian. The northern Caspian is shallow. The deepest depth of the Middle Caspian in the region of the Derbent depression is about 788 m. Beyond the Absheron threshold, the South Caspian begins, it is here that the sea is the deepest: about 1025 m. For clarity, imagine three Eiffel towers stacked on top of each other.
Many secrets and mysteries are connected with the Caspian Sea. In 1939, archaeologists-divers found a flooded ancient Gostiny Dvor (caravanserai) in the Baku Bay. Many inscriptions have been preserved on the walls, indicating that the building was erected in 1234-1235. Maybe it's leftovers ancient city Sabail. Nearby, ancient quarries were discovered in the sea. And in 1940, when laying a dam on the Absheron Peninsula, an ancient cemetery was discovered at the bottom of the sea. Burials date back to the 1st century BC. It can be assumed that the level of the Caspian in those days was about four meters lower than the present one.
It is no coincidence that the inscription on geographical map, compiled in 1320, reads: “The sea arrives every year on one palm, and already many good cities flooded"
Instrumental measurement of the level of the Caspian Sea and systematic observations of its fluctuations have been carried out since 1837. The highest water level was recorded in 1882 (−25.2 m), the lowest - in 1977 (−29.0 m), since 1978 the water level has risen and in 1995 reached −26.7 m, since 1996 began to decline again, and since 2001 - to rise again and reached -26.3 m. The reasons for this "behavior" of the Caspian Sea are climate change, as well as geological and anthropogenic factors.
Another mystery of the unique sea-lake is the Caspian seal: scientists cannot answer the question of where the animal of northern latitudes came from in the Caspian Sea. In total, 1809 species of various groups of animals live in the Caspian Sea. The Caspian is also famous for its valuable fish species, in particular sturgeons. Their reserves account for up to 80% of the world's resources. The most valuable caviar is not black, as many people used to think, but white. Albino beluga caviar "Almas" has a color from light gray to white. The lighter, the more expensive: the cost of 100 grams is 2000 US dollars. This fish is caught in the Caspian Sea off the coast of Iran.
Many oil and gas fields are being developed in the Caspian Sea. The first oil well was drilled on the Absheron Peninsula near Baku back in 1820. In 1949, for the first time, they began to extract oil from the bottom of the Caspian Sea. Salt, limestone, stone, sand and clay are also mined on the coast of the Caspian Sea and the Caspian shelf.
The Caspian Sea washes the shores of five countries: Kazakhstan, Azerbaijan, Turkmenistan, Iran and Russia. Caspian Day has been celebrated in every country for several years now, reminding that the Caspian is not just a water and breadwinner for the peoples inhabiting its shores, but a very fragile ecosystem.
By the way, in 1978, World Maritime Day appeared on the calendar of world events, which refers to the UN international days, designed to draw the attention of mankind to the problems of the hydraulic system. There is also an international day of the Black Sea: in 1996, representatives of Russia, Ukraine, Bulgaria, Romania, Turkey and Georgia signed a strategic action plan to save the Black Sea. In this series, the day of the Caspian Sea is also, rather, not a holiday, but a warning, a warning to people about how everything is interconnected in this world and how it is possible, mercilessly exploiting, to lose what is dear to everyone.
Marina Parenskaya
Caspian SeaThe Caspian Sea is one of the most amazing enclosed bodies of water on Earth.
Over the centuries, the sea has changed more than 70 names. The modern came from the Caspians - the tribes inhabiting the central and southeastern part of Transcaucasia 2 thousand years BC.
Geography of the Caspian Sea
The Caspian Sea is located at the junction of Europe with Asia and is geographically divided into the South, North and Middle Caspian.
Average and Northern part The sea belongs to Russia, the south to Iran, the east to Turkmenistan and Kazakhstan, and the southwest to Azerbaijan.
For many years, the Caspian states have been dividing the Caspian water area among themselves, and quite sharply at that.
Caspian sea map
Lake or sea?
In fact, the Caspian Sea is the world's largest lake, but has a number of nautical signs.
These include: a large body of water, strong storms with high waves, high and low tides.
But the Caspian has no natural connection with the World Ocean, which makes it impossible to call it a sea.
At the same time, thanks to the Volga and artificially created channels, such a connection appeared.
The salinity of the Caspian Sea is 3 times lower than the usual sea level, which does not allow classifying the reservoir as a sea.
There were times when the Caspian Sea was indeed part of the World Ocean.
Several tens of thousands of years ago, the Caspian was connected to the Sea of Azov, and through it to the Black and Mediterranean.
As a result of long-term processes occurring in the earth's crust, formed Caucasian mountains that isolated the reservoir.
Connection between the Caspian and Black Seas for a long time was carried out through the strait (Kumo-Manych depression) and gradually stopped.
Physical quantities
Area, volume, depth
The area, volume and depth of the Caspian Sea are not constant and directly depend on the water level.
On average, the area of \u200b\u200bthe reservoir is 371,000 km², the volume is 78,648 km³ (44% of all world lake water reserves).
Depth of the Caspian Sea in comparison with lakes Baikal and Tanganyika
The average depth of the Caspian is 208 m, the northern part of the sea is considered the shallowest. The maximum depth is 1025 m, noted in the South Caspian depression.
In depth, the Caspian is second only to Baikal and Tanganyika.
The length of the lake from north to south is about 1200 km, from west to east an average of 315 km. The length of the coastline is 6600 km, with islands - about 7 thousand km.
coast
Mostly, the coast of the Caspian Sea is low-lying and smooth.
In the northern part- heavily indented by the river channels of the Urals and the Volga. The swampy local shores are located very low.
Eastern Shores adjacent to semi-desert zones and deserts, covered with limestone deposits.
The most winding coasts are in the west in the region of the Apsheron Peninsula, and in the east - in the area of the Kazakh Gulf and Kara-Bogaz-Gol.
sea water temperature
The temperature of the Caspian Sea in different time of the year
Average water temperature in winter in the Caspian it fluctuates from 0 °С in the northern part and up to +10 °С in the southern part.
In the waters of Iran, the temperature does not fall below +13 °C.
With the onset of cold weather, the shallow northern part of the lake is covered with ice, which lasts for 2-3 months. The thickness of the ice cover is 25-60 cm, at especially low temperatures it can reach 130 cm. In late autumn and winter, drifting ice floes can be observed in the north.
Summer average temperature
the surface of the water in the sea is + 24 °C.
Most of the sea warms up to +25 °C ... +30 °C.
Warm water and beautiful sandy, occasionally shell and pebble beaches create excellent conditions for a full beach holiday.
In the eastern part of the Caspian Sea near the city of Begdash, during the summer months, abnormally low water temperature.
Nature of the Caspian Sea
Islands, peninsulas, bays, rivers
The Caspian Sea includes about 50 large and medium-sized islands, total area which is 350 km².
The largest of them are: Ashur-Ada, Garasu, Gum, Dash and Boyuk-Zira. The largest peninsulas are: Agrakhansky, Absheronsky, Buzachi, Mangyshlak, Miankale and Tyub-Karagan.
Tyuleniy Island in the Caspian Sea, part of the Dagestan Reserve
To the largest bays of the Caspian include: Agrakhan, Kazakh, Kizlyar, Dead Kultuk and Mangyshlak.
In the east is salt lake Kara-Bogaz-Gol, previously a lagoon connected to the sea by a strait.
In 1980, a dam was built on it, through which water from the Caspian goes to Kara-Bogaz-Gol, where it then evaporates.
130 rivers flow into the Caspian Sea located mainly in its northern part. The largest of them: Volga, Terek, Sulak, Samur and Ural.
The average annual runoff of the Volga is 220 km³. 9 rivers have a delta-shaped mouth.
Flora and fauna
About 450 species of phytoplankton live in the Caspian Sea, including algae, aquatic and flowering plants. Of the 400 species of invertebrates, worms, crustaceans and mollusks predominate. There are a lot of small shrimp in the sea, which is an object of fishing.
More than 120 species of fish live in the Caspian and Delta. Fishing objects are sprat (“Kilkin fleet”), catfish, pike, bream, pike perch, kutum, mullet, vobla, rudd, herring, white fish, pike perch, goby, grass carp, burbot, asp and pike perch. Stocks of sturgeon and salmon are currently depleted, however, the sea is the largest supplier of black caviar in the world.
Fishing in the Caspian Sea is allowed all year round except for the period from late April to late June. On the coast there are many fishing bases with all amenities. Fishing in the Caspian is a great pleasure. In any part of it, including in large cities, the catch is unusually rich.
The lake is famous for its large variety of waterfowl.. Geese, ducks, loons, gulls, waders, sea eagles, geese, swans and many others come to the Caspian during migration or nesting.
The largest number of birds - over 600 thousand individuals is observed in the mouths of the Volga and the Urals, in the bays of Turkmenbashi and Kyzylagach. During the hunting season, a huge number of fishermen come here not only from Russia, but also from countries near and far abroad.
Nerpa Caspian
The only mammal lives in the Caspian Sea. This is the Caspian seal or seal. Until recently, the seals swam close to the beaches, everyone could admire the amazing animal with round black eyes, the seals behaved very friendly.
Now the seal is on the verge of extinction.
Cities on the Caspian Sea
Baku is the largest city on the coast of the Caspian Sea..
The population of one of the most beautiful cities in the world is over 2.5 million people. Baku is spread out on the most picturesque Absheron peninsula and is surrounded on three sides by the waters of the warm and oil-rich Caspian Sea.
Less big cities: the capital of Dagestan is Makhachkala, Kazakh Aktau, Turkmen Turkmenbashi and Iranian Bandar Anzeli.
Baku Bay, Baku - a city on the Caspian Sea
Interesting Facts
Scientists are still arguing about whether to call a reservoir a sea or a lake.
The level of the Caspian Sea is gradually decreasing.
The Volga delivers most of the water to the Caspian.
90% of black caviar is mined in the Caspian Sea. Among them, the most expensive is Almas beluga caviar ($2,000 per 100 g).
Companies from 21 countries are participating in the development of oil fields in the Caspian Sea. According to Russian estimates, hydrocarbon reserves in the sea amount to 12 billion tons.
American scientists claim that one fifth of the world's hydrocarbon reserves are concentrated in the depths of the Caspian Sea. This is more than the combined reserves of such oil-producing countries as Kuwait and Iraq.
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.
The eastern coast of the Caspian adjoins 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. The direct connection of 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
modern look and geographical position The Caspian lake is caused by continuous processes occurring on the surface of the Earth and in its bowels. 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 common history 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 - this is the northern part of the lake. The 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 southern shores sea, he owns 15% of the entire length of the 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 littoral states has been the most poignant 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
Caspian from ancient times for local residents served as a waterway.
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 preserving the sturgeon population is of international importance, it is solved 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 of various groups of animals live in the Caspian Sea. 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 extraction also could not but affect the ecological situation of the region.
Sea level fluctuations
The water level in the Caspian Lake is not constant. This is evidenced by evidence relating to the IV century BC. The ancient Greeks who explored the sea discovered big bay at the confluence of the Volga. The existence of a shallow strait between the Caspian and the Sea of Azov was also discovered by them.
There are other data on the water level in the Caspian Lake. The facts show that the level was much lower than it is now. The evidence is provided by the ancient 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 fresh water. This is directly related to industrial production, mining and other human activities in the catchment area.
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.
, Kazakhstan, Turkmenistan, Iran , Azerbaijan
Geographical position
Caspian Sea - view from space.
The Caspian Sea is located at the junction of two parts of the Eurasian continent - Europe and Asia. The length of the Caspian Sea from north to south is approximately 1200 kilometers (36°34 "-47°13" N), from west to east - from 195 to 435 kilometers, on average 310-320 kilometers (46°-56° v. d.).
The Caspian Sea is conditionally divided according to physical and geographical conditions into 3 parts - the North Caspian, the Middle Caspian and the South Caspian. The conditional border between the North and Middle Caspian runs along the line of about. Chechnya - Cape Tyub-Karagansky, between the Middle and South Caspian - along the line of about. Residential - Cape Gan-Gulu. The area of the Northern, Middle and Southern Caspian is 25, 36, 39 percent respectively.
Coast of the Caspian Sea
Coast of the Caspian Sea in Turkmenistan
The territory adjacent to the Caspian Sea is called the Caspian Sea.
Peninsulas of the Caspian Sea
- Ashur-Ada
- Garasu
- Zyanbil
- Hara Zira
- Sengi-Mugan
- Chygyl
Bays of the Caspian Sea
- Russia (Dagestan, Kalmykia and Astrakhan region) - in the west and north-west, the length of the coastline is about 1930 kilometers
- Kazakhstan - in the north, northeast and east, the length of the coastline is about 2320 kilometers
- Turkmenistan - in the southeast, the length of the coastline is about 650 kilometers
- Iran - in the south, the length of the coastline is about 1000 kilometers
- Azerbaijan - in the southwest, the length of the coastline is about 800 kilometers
Cities on the coast of the Caspian Sea
On the Russian coast the cities are located - Lagan, Makhachkala, Kaspiysk, Izberbash and the most Southern City Russian Derbent. port city The Caspian Sea is also considered Astrakhan, which, however, is not located on the shores of the Caspian Sea, but in the Volga Delta, 60 kilometers from north coast Caspian Sea.
Physiography
Area, depth, volume of water
The area and volume of water in the Caspian Sea varies significantly depending on fluctuations in water levels. At a water level of −26.75 m, the area is approximately 371,000 square kilometers, the volume of water is 78,648 cubic kilometers, which is approximately 44% of the world's lake water reserves. The maximum depth of the Caspian Sea is in the South Caspian depression, 1025 meters from its surface level. In terms of maximum depth, the Caspian Sea is second only to Baikal (1620 m) and Tanganyika (1435 m). The average depth of the Caspian Sea, calculated from the bathygraphic curve, is 208 meters. At the same time, the northern part of the Caspian Sea is shallow, its maximum depth does not exceed 25 meters, and the average depth is 4 meters.
Water level fluctuations
Vegetable world
The flora of the Caspian Sea and its coast is represented by 728 species. Of the plants in the Caspian Sea, algae predominate - blue-green, diatoms, red, brown, char and others, of flowering - zoster and ruppia. By origin, the flora belongs mainly to the Neogene age, however, some plants were brought into the Caspian Sea by man either consciously or on the bottoms of ships.
History of the Caspian Sea
Origin of the Caspian Sea
Anthropological and cultural history of the Caspian Sea
Finds in Huto Cave south coast The Caspian Sea testifies that a person lived in these parts about 75 thousand years ago. The first mention of the Caspian Sea and the tribes living on its coast are found in Herodotus. Approximately in the V-II centuries. BC e. Saka tribes lived on the coast of the Caspian Sea. Later, during the period of the settlement of the Turks, in the period of the 4th-5th centuries. n. e. Talysh tribes (Talysh) lived here. According to ancient Armenian and Iranian manuscripts, the Russians sailed the Caspian Sea from the 9th-10th centuries.
Exploration of the Caspian Sea
The exploration of the Caspian Sea was started by Peter the Great, when, on his orders, an expedition was organized in 1714-1715 under the leadership of A. Bekovich-Cherkassky. In the 1720s, hydrographic studies were continued by the expedition of Karl von Werden and F.I. Soymonov, later by I.V. Tokmachev, M.I. Voinovich and other researchers. At the beginning of the 19th century, instrumental surveying of the banks was carried out by I.F. Kolodkin, in the middle of the 19th century. - instrumental geographic survey under the guidance of N. A. Ivashintsev. Since 1866, for more than 50 years, expeditionary research on the hydrology and hydrobiology of the Caspian Sea has been carried out under the leadership of N. M. Knipovich. In 1897, the Astrakhan Research Station was founded. In the first decades of Soviet power in the Caspian Sea, geological research by I. M. Gubkin and other Soviet geologists was actively carried out, mainly aimed at finding oil, as well as research on the study of the water balance and fluctuations in the level of the Caspian Sea.
Economy of the Caspian Sea
Oil and gas
Many oil and gas fields are being developed in the Caspian Sea. The proven oil resources in the 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 the Caspian Sea began in 1820, when the first oil well was drilled on the Absheron shelf near Baku. In the second half of the 19th century, oil production began on an industrial scale on the Absheron Peninsula, and then on other territories.
Shipping
Shipping is developed in the Caspian Sea. Ferry crossings operate on the Caspian Sea, in particular, Baku - Turkmenbashi, Baku - Aktau, Makhachkala - Aktau. The Caspian Sea has a navigable connection with the Sea of Azov through the Volga and Don rivers and the Volga-Don Canal.
Fishing and seafood
Fishing (sturgeon, bream, carp, pike perch, sprat), caviar, and seal fishing. More than 90 percent of the world's sturgeon catch is carried out in the Caspian Sea. In addition to industrial production, illegal production of sturgeon and their caviar flourishes in the Caspian Sea.
Recreational resources
The natural environment of the Caspian coast with sandy beaches, mineral waters and therapeutic mud in the coastal zone creates good conditions for relaxation and treatment. At the same time, according to the degree of development of resorts and the tourism industry Caspian coast noticeably loses to the Black Sea coast of the Caucasus. However, in last years the tourism industry is actively developing on the coast of Azerbaijan, Iran, Turkmenistan and Russian Dagestan. The resort area in the Baku region is actively developing in Azerbaijan. At the moment, a world-class resort has been created in Amburan, another modern tourist complex is being built near the village of Nardaran, recreation in the sanatoriums of the villages of Bilgah and Zagulba is very popular. A resort area is also being developed in Nabran, in the north of Azerbaijan. However high prices, generally low level service and the lack of advertising lead to the fact that there are almost no foreign tourists in the Caspian resorts. development tourism industry in Turkmenistan, a long-term policy of isolation hinders, in Iran - sharia law, because of which the mass vacation of foreign tourists on the Caspian coast of Iran is impossible.
Environmental problems
The environmental problems of the Caspian Sea are associated with water pollution as a result of oil production and transportation on the continental shelf, the flow of pollutants from the Volga and other rivers flowing into the Caspian Sea, the vital activity of coastal cities, as well as the flooding of individual objects due to the rise in the level of the Caspian Sea. Predatory harvesting of sturgeons and their caviar, rampant poaching lead to a decrease in the number of sturgeons and forced restrictions on their production and export.
International status of the Caspian Sea
Legal status of the Caspian Sea
After the collapse of the USSR, the division of the Caspian Sea has long been and still remains the subject of unsettled disagreements related to the division of the resources of the Caspian shelf - oil and gas, as well as biological resources. For a long time there were negotiations between the Caspian states on the status of the Caspian Sea - Azerbaijan, Kazakhstan and Turkmenistan insisted on dividing the Caspian along the median line, Iran - on dividing the Caspian along one fifth between all the Caspian states.
With regard to the Caspian Sea, the key is the physical and geographical circumstance that it is a closed inland water body that does not have a natural connection with the World Ocean. Accordingly, the norms and concepts of international maritime law, in particular, the provisions of the UN Convention on the Law of the Sea of 1982, should not automatically apply to the Caspian Sea. Based on this, it would be unlawful to apply such concepts as “territorial sea”, “exclusive economic zone”, “continental shelf”, etc.
The current legal regime of the Caspian Sea was established by the Soviet-Iranian treaties of 1921 and 1940. These treaties provide for freedom of navigation throughout the sea, freedom of fishing, with the exception of ten-mile national fishing zones, and a ban on navigation in its waters of ships flying the flag of non-Caspian states.
Negotiations about legal status Caspian is currently ongoing.
Delimitation of sections of the bottom of the Caspian Sea for the purpose of subsoil use
The Russian Federation concluded an agreement with Kazakhstan on the delimitation of the bottom of the northern part of the Caspian Sea in order to exercise sovereign rights to subsoil use (dated July 6, 1998 and the Protocol dated May 13, 2002), an agreement with Azerbaijan on the delimitation of adjacent sections of the bottom of the northern part of the Caspian Sea (dated September 23, 2002), as well as the trilateral Russian-Azerbaijani-Kazakhstan agreement on the junction of the demarcation lines of adjacent sections of the Caspian Sea bottom (dated May 14, 2003), which established geographical coordinates dividing lines delimiting seabed areas within which the parties exercise their sovereign rights in the field of exploration and extraction of mineral resources.
