CaspAndyskoe mOre(Caspian) is the largest enclosed body of water on Earth. In size, the Caspian Sea is much larger than lakes such as Superior, Victoria, Huron, Michigan, and Baikal. According to formal characteristics, the Caspian Sea is an endorheic lake. However, given its large size, brackish waters and a regime similar to the sea, this body of water is called a sea.
According to one hypothesis, the Caspian Sea (among the ancient Slavs – the Khvalynsk Sea) received its name in honor of the Caspian tribes who lived BC on its southwestern coast.
The Caspian Sea washes the shores of five states: Russia, Azerbaijan, Iran, Turkmenistan and Kazakhstan.
The Caspian Sea is elongated in the meridional direction and is located between 36°33΄ and 47°07΄ N latitude. and 45°43΄ and 54°03΄ E. (without Kara-Bogaz-Gol Bay). The length of the sea along the meridian is about 1200 km; average width – 310 km. North Shore Caspian Sea bordered by the Caspian lowland, eastern by the deserts of Central Asia; in the west the Caucasus Mountains approach the sea, in the south the Elburz ridge stretches near the coast.
The surface of the Caspian Sea is located significantly below the level of the World Ocean. Its current level fluctuates around -27...-28 m. These levels correspond to a sea surface area of 390 and 380 thousand km 2 (without the Kara-Bogaz-Gol Bay), a water volume of 74.15 and 73.75 thousand km 3, average depth approximately 190 m.
The Caspian Sea is traditionally divided into three large parts: the Northern (24% of the sea area), the Middle (36%) and the Southern Caspian (40%), which differ significantly in morphology and regime, as well as the large and isolated Kara-Bogaz-Gol Bay. The northern, shelf part of the sea is shallow: its average depth is 5–6 m, maximum depths are 15–25 m, the volume is less than 1% of the total water mass of the sea. The Middle Caspian is an isolated basin with an area of maximum depths in the Derbent depression (788 m); its average depth is about 190 m. In the South Caspian, the average and maximum depths are 345 and 1025 m (in the South Caspian depression); 65% of the sea's water mass is concentrated here.
There are about 50 islands in the Caspian Sea with total area approximately 400 km 2; the main ones are Tyuleniy, Chechen, Zyudev, Konevsky, Dzhambaysky, Durneva, Ogurchinsky, Apsheronsky. Length coastline approximately 6.8 thousand km, with islands - up to 7.5 thousand km. The shores of the Caspian Sea are diverse. In the northern and eastern parts they are quite rugged. Here are the large bays of Kizlyarsky, Komsomolets, Mangyshlaksky, Kazakhsky, Kara-Bogaz-Gol, Krasnovodsky and Turkmensky, many bays; at west coast- Kizilagachsky. The largest peninsulas are Agrakhansky, Buzachi, Tyub-Karagan, Mangyshlak, Krasnovodsky, Cheleken and Apsheronsky. The most common shores are accumulative; areas with abrasion shores are found along the contour of the Middle and Southern Caspian Sea.
Over 130 rivers flow into the Caspian Sea, the largest of which are the Volga , Ural, Terek, Sulak, Samur, Kura, Sefidrud, Atrek, Emba (its flow enters the sea only in high-water years). Nine rivers have deltas; the largest are located at the mouths of the Volga and Terek.
The main feature of the Caspian Sea, as an endorheic reservoir, is instability and a wide range of long-term fluctuations in its level. This most important hydrological feature of the Caspian Sea has a significant impact on all its other hydrological characteristics, as well as on the structure and regime of river mouths and coastal zones. In the Caspian Sea level varied in the range of ~200 m: from -140 to +50 m BS; at -34 to -20 m BS. From the first third of the 19th century. and until 1977, sea level dropped by about 3.8 m - to the lowest level in the last 400 years (-29.01 m BS). In 1978–1995 The level of the Caspian Sea rose by 2.35 m and reached -26.66 m BS. Since 1995, a certain downward trend in level has been dominant - to -27.69 m BS in 2013.
During major events, the northern coast of the Caspian Sea shifted to the Samara Luka on the Volga, and perhaps further. During maximum transgressions, the Caspian Sea turned into a drainage lake: excess water flowed through the Kuma-Manych depression into the Sea of Azov and further into the Black Sea. In extreme regressions South coast The Caspian Sea shifted to the Absheron threshold.
Long-term fluctuations in the level of the Caspian Sea are explained by changes in the structure of the water balance of the Caspian Sea. Sea level rises when the incoming part of the water balance (primarily the water flow of rivers) increases and exceeds the outgoing part, and decreases if the influx of river water decreases. The total water flow of all rivers averages 300 km 3 /year; while the five largest rivers account for almost 95% (the Volga gives 83%). During the period of the lowest sea level, in 1942–1977, the river flow was 275.3 km 3 /year (of which 234.6 km 3 /year was the Volga runoff), precipitation - 70.9, underground flow - 4 km 3 /year, and evaporation and outflow into the Kara-Bogaz-Gol Bay are 354.79 and 9.8 km 3 /year. During the period of intense sea level rise, in 1978–1995, - respectively 315 (Volga - 274.1), 86.1, 4, 348.79 and 8.7 km 3 /year; in the modern period - 287.4 (Volga - 248.2), 75.3, 4, 378.3 and 16.3 km 3 /year.
Intra-annual changes in the level of the Caspian Sea are characterized by a maximum in June–July and a minimum in February; the range of intra-annual level fluctuations is 30–40 cm. Surge level fluctuations occur throughout the sea, but they are most significant in the northern part, where, with maximum surges, the level can rise by 2–4.5 m and the edge “retreat” by several tens kilometers inland, and during surges it will drop by 1–2.5 m. Seiche and tidal level fluctuations do not exceed 0.1–0.2 m.
Despite the relatively small size of the reservoir, there is strong excitement in the Caspian Sea. The highest wave heights in the Southern Caspian Sea can reach 10–11 m. Wave heights decrease in the direction from south to north. Storm waves can develop at any time of the year, but they are more frequent and more dangerous in the cold half of the year.
In the Caspian Sea as a whole, wind currents predominate; Nevertheless, in the estuary coastal zones of large rivers, runoff currents play a significant role. In the Middle Caspian, cyclonic water circulation predominates, in the Southern Caspian - anticyclonic. In the northern part of the sea, patterns of wind currents are more irregular and depend on the characteristics and variability of the wind, bottom topography and coastal contours, river flow and aquatic vegetation.
Water temperature is subject to significant latitudinal and seasonal changes. In winter, it varies from 0–0.5 o C at the ice edge in the north of the sea to 10–11 o C in the south. In summer, the water temperature in the sea averages 23–28 o C, and in shallow coastal waters in the Northern Caspian Sea it can reach 35–40 o C. At depths, a constant temperature is maintained: deeper than 100 m it is 4–7 o C.
It only freezes in winter Northern part Caspian Sea; in severe winter - the entire Northern Caspian and coastal zones of the Middle Caspian. Freeze-up in the Northern Caspian lasts from November to March.
Water salinity changes especially sharply in the northern part of the sea: from 0.1‰ at the mouth shores of the Volga and Ural to 10–12‰ on the border with the Middle Caspian. In the Northern Caspian Sea, the temporal variability of water salinity is also great. In the middle and southern parts of the sea, salinity fluctuations are small: it is generally 12.5–13.5‰, increasing from north to south and from west to east. The highest water salinity is in the Kara-Bogaz-Gol Bay (up to 300‰). With depth, water salinity increases slightly (by 0.1–0.3‰). The average salinity of the sea is about 12.5‰.
More than a hundred species of fish live in the Caspian Sea and the mouths of the rivers flowing into it. There are Mediterranean and Arctic invaders. The fish species are goby, herring, salmon, carp, mullet and sturgeon. The latter include five species: sturgeon, beluga, stellate sturgeon, thorn and sterlet. The sea can produce up to 500–550 thousand tons of fish annually, if overfishing is not allowed. Of the marine mammals, the endemic Caspian seal lives in the Caspian Sea. 5–6 million waterfowl migrate through the Caspian region annually.
The economy of the Caspian Sea is associated with oil and gas production, shipping, fishing, seafood, various salts and minerals (Kara-Bogaz-Gol Bay), using recreational resources. The explored oil resources in the Caspian Sea amount to about 10 billion tons, the total resources of oil and gas condensate are estimated at 18–20 billion tons. Oil and gas production is carried out on an ever-increasing scale. The Caspian Sea is used and by water transport, including along the river-sea and sea-river routes. The main ports of the Caspian Sea: Astrakhan, Olya, Makhachkala (Russia), Aktau, Atyrau (Kazakhstan), Baku (Azerbaijan), Noushehr, Bandar-Anzeli, Bandar-Torkemen (Iran) and Turkmenbashi (Turkmenistan).
Economic activities and hydrological features of the Caspian Sea create a number of serious environmental and water management problems. Among them: anthropogenic pollution of river and sea waters (mainly with petroleum products, phenols and surfactants), poaching and reduction of fish stocks, especially sturgeon; damage to the population and coastal economic activity due to large-scale and rapid changes in the level of the reservoir, the impact of numerous dangerous hydrological phenomena and hydrological-morphological processes.
The total economic damage for all Caspian countries associated with the rapid and significant recent rise in the level of the Caspian Sea, the flooding of part of the coastal land, and the destruction of coastlines and coastal structures, amounted to an estimated amount of 15 to 30 billion US dollars. Urgent engineering measures were required to protect the coast.
A sharp drop in the level of the Caspian Sea in the 1930s–1970s. resulted in less damage, but it was still significant. Navigable approach channels became shallow, the shallow seaside at the mouths of the Volga and Ural became heavily overgrown, which became an obstacle to the passage of fish into the rivers to spawn. Fish passages had to be built through the mentioned seashores.
Among the unresolved problems is the lack of an international agreement on the international legal status of the Caspian Sea, the division of its waters, bottom and subsoil.
The Caspian Sea is the object of many years of research by specialists from all Caspian states. Such domestic organizations as the State Oceanographic Institute, the Institute of Oceanology of the Russian Academy of Sciences, the Hydrometeorological Center of Russia, the Caspian Research Institute of Fisheries, the Faculty of Geography of the Moscow State University took an active part in the study of the Caspian Sea. state university and etc.
Pearl unique beauty and identity is the Caspian Sea. This is a unique, the only enclosed body of water in the world with a fragile and invaluable ecosystem. Its uniqueness attracts world attention. The Caspian Sea is considered the largest inland body of water in the world, located at the junction of Asia and Europe. Poets, philosophers, historians, and geographers devoted a lot of their work to this amazing natural creation. Among them: Homer, Herodotus, Aristotle. The biological environment of the Caspian Sea is also unique. But first things first. We invite you to find out about the depth, level, location of this reservoir, which countries are washed by the Caspian Sea. Well, let's go...
Historical information
Many people are interested in where the Caspian Sea is located and the history of its origin. But few people know that it is of oceanic origin. Thirteen million years ago this place was the bottom of the ocean. As a result of natural disasters, the Alps arose and disconnected the Sarmatian Sea from the Mediterranean. 5 million years passed, and the Sarmatian Sea was divided into smaller bodies of water, which included the Black and Caspian Seas. The connection and division of waters continued for a long time. And so 2 million years ago the Caspian Sea was completely cut off from the World Ocean. This was the beginning of its formation. History confirms that during the period of its formation, the depth and area of the Caspian Sea changed repeatedly.
Today the Caspian Sea is classified as the largest closed lake. Because of its enormous size, it is commonly called the sea. And also because it formed on the oceanic crust.
Today the Caspian makes up 44% of the planet's lake waters. Throughout its formation, different tribes and peoples gave the lake about 70 names. The Greeks called it Hyrcanian (Djurdzhanian) lake from the name of the city of Gorgan and the province of Hyrcania. The ancient Russians called it the Khvalyn Sea, from the name that lived in the coastal region of the Khvalis people. Arabs, Persians, Azerbaijanis, Turks, Crimean Tatars called it the Khazar Sea. Once upon a time, in the delta of the Kura River, which flows into the reservoir, there was an island and a city, after which it was called the Abeskun Sea. Later this city was flooded. There was also the name Saraiskoye Lake. In honor of the city of Derbant (Dagestan), it was called the Derbent Sea. There was also the name Sihai et al.
Geographical location
Many people want to know where the Caspian Sea is located on the map. This place is located at the junction of Europe and Asia. The physical and geographical conditions of the sea make it possible to divide it into three parts:
- The share of the Northern Caspian occupies 25% of the reservoir.
- The Middle Caspian zone has 36%.
- The component of the southern part of the lake is 39%.
The Northern and Middle Caspian Sea separates the island of Chechen from Cape Tyub-Karagan. The Middle and Southern Caspian Sea shares Chilov Island with Cape Gan-Gulu.
The territory adjacent to the lake is called the Caspian region. The size of the Caspian Sea is amazing. The coastline stretches approximately 6,500 - 6,700 kilometers. The banks have a low and smooth structure. The northern part of the coastline is cut by water channels and islands of the Ural and Volga deltas. The banks are mostly low and swampy, covered with thickets. The east coast has a limestone structure. In the west the banks are very winding.
Relief and depth, area of the Caspian Sea
These figures fluctuate constantly. As a result, they affect sea levels. The Caspian Sea thus changes the area and volume of water. If its level is 26.75 km, then its area is 371,000 km 2. And what is the maximum and average depth Caspian Sea? In terms of maximum depth, it is second only to Baikal and Tanganyika. The maximum depth in the South Caspian depression is 1,025 m. The average depth of the Caspian Sea is helped to calculate by a bathygraphic curve, which indicates a depth of 208 m. In the north, the reservoir is shallower - 25 m. The Middle Caspian has many deep depressions, continental slopes, and shelves. Here the average depth reaches 192 m. The Derbent depression has a depth of 788 m.
The length of the lake from north to south is 1,200 km, and the width of the Caspian Sea from west to east is up to 435 km. The relief of the northern part of the lake is flat, with accumulative islands and banks. The southern part of the Caspian shelf is rich in shell sands and deep-sea areas with silty sediments. Sometimes there are bedrocks exposed here.
Peninsulas, islands and bays of the Caspian Sea
There are a number of large peninsulas located on the area of the Caspian Sea. On the west coast, near Azerbaijan, is the Absheron Peninsula. It is here that the cities of Baku and Sumgait are located. On the eastern side (territory of Kazakhstan) is the Mangyshlak Peninsula. The city of Aktau was built here. It is also worth noting the following large peninsulas: Miankale, Tyub-Karagan, Buzachi, Agrakhan Peninsula.
The total area of the large and medium-sized islands of the Caspian Sea is 350 km 2 . There are about 50 such islands. The largest and most famous are: Ashur-Ada, Garasu, Chechen, Chigil, Gum, Dash-Zira, Ogurchinsky, etc.
Such a huge body of water cannot exist without bays. The Agrakhan, Kizlyar, Mangyshlak, and Kazakh bays are famous. It is also worth remembering Kaydak Bay, Kenderli, Turkmen, Astrakhan, Hasan-Kuli, Anzeli.
The salt lake Kara-Bogaz-Gol is considered a special bay-lagoon of the Caspian Sea. In 1980, a dam was built that separates this strait from the Caspian Sea. Every year 8-10 km 3 of water flows from the Caspian Sea to Kara-Bogaz-Gol.
Which countries is washed by the Caspian Sea?
The Intergovernmental Economic Conference of the Caspian States established that five coastal countries wash the Caspian Sea. Which ones exactly? In the north, northeast and east it borders with Kazakhstan. The coastline is 2,320 km. Who does the Caspian Sea border on in the south? This is Iran with a coastline of 724 km. In the southeast is Turkmenistan with a coastline of about 1,200 km. The north-west and west of the Caspian Sea is occupied by Russia with a length of 695 km. Azerbaijan stretches for 955 km in the southwest. This is a kind of “Caspian Five”.
Coastline and nearby cities
Many cities, ports and resorts are located on the Caspian Sea. In Russia, the largest objects are considered to be: Kaspiysk, Makhachkala, Izberbash, Lagan, Dagestan Lights, Derbent. Astrakhan is the largest port city of the Caspian Sea, located in the Volga delta (60 km from north coast).
In Azerbaijan, Baku is considered the largest port city. Its location is in the southern part of the Absheron Peninsula. The city is home to 2.5 million people. Sumgayit is located a little to the north. Lankaran is located near the southern border of Azerbaijan. In the southeast of the Absheron Peninsula there is an oil workers’ settlement - Neftyanye Kamni.
In Turkmenistan, on the northern shore of the Krasnovodsk Bay, the city of Turkmenbashi is located. Avaza is a major resort in this country.
In Kazakhstan, the port city of Aktau was built near the Caspian Sea. To the north, in the delta of the Ural River is Atyrau. In Iran, on the southern coast of the reservoir, Bandar Anzeli is located.
Rivers flowing into the Caspian Sea
130 large and small rivers flow into the Caspian Sea. Nine of them have a deltoid opening. Among the largest rivers we highlight the Volga, Ural, Terek, Samur, Sulak, Emba, Kura, Atrek. The largest river flowing into the reservoir is the Volga. On average, 215-224 km 3 of water flows out of it per year. All of the above rivers replenish the annual water supply of the Caspian Sea by 88-90%.
Currents, flora and fauna of the Caspian Sea
For those who are interested in where the Caspian Sea flows, the answer is already clear - it is a closed body of water. The water circulates in it thanks to winds and drains. Most of the water flows into the Northern Caspian, so northern currents circulate there. These intense currents transport water to the western coast of the Absheron Peninsula. There the current changes into two branches - one moves parallel to the western shore, the other - to the eastern.
The fauna of the Caspian basin is represented by 1810 animal species. 415 of them are representatives of vertebrates. About 100 species of fish swim in the Caspian Sea, and they also live here. a large number of sturgeon. Freshwater fish are also found here, including pike perch, carp, and roach. There are also a lot of carp, mullet, sprat, kutum, bream, salmon, perch, and pike in the sea. It is worth remembering another inhabitant - the Caspian seal.
The flora of the Caspian Sea and coastal zone includes 730 species. It is important to note that the reservoir is overgrown with blue-green, diatoms, red, brown, and chara algae. The most common flowering algae are ruppia and zoster. The age of the Caspian flora dates back to the Neogene period. Many plants entered the Caspian Sea with the help of ships or conscious human actions.
Research works
Between 285 and 282 BC. Greek king Seleuko I ordered the geographer Patroclus the Macedonian to explore Caspian lake. Later this work was continued by order of Peter the Great. For this purpose, an expedition was specially organized, led by A. Bekovich-Cherkassky. Later, research was continued by the expedition of Karl von Werden. The following scientists also studied the Caspian Sea: F.I. Simonov, I.V. Tokmachev, M.I. Voinovich.
IN late XIX instrumental coastal survey was carried out by I.F. Kolodkin, later - N.A. Ivashentseva. During the same period, N.M. studied the hydrology and hydrobiology of the Caspian Sea for 50 years. Knipovich. The year 1897 was marked by the founding of the Astrakhan Research Station. At the beginning of the Soviet era, the Caspian was studied by I.M. Gubkin and other geologists. They aimed their work at searching for oil, studying the aquatic environment, and changes in the level of the Caspian Sea.
Economic sphere, shipping, fishing
Many gas and oil deposits have been found in the Caspian Sea. Scientists have proven that there are about 10 billion tons of oil resources here, and together with gas condensate - 20 billion tons. Since 1820, oil production began on the Absheron shelf, near Baku. Then oil production began on an industrial scale in other areas. Oil production from the bottom of the Caspian Sea began in 1949, at Neftyanye Kamni. Mikhail Kaverochkin was involved in drilling the long-awaited oil well. In addition to oil and gas, salt, limestone, stone, sand, and clay are mined in the Caspian Sea.
Shipping is also given a lot of attention here. Constantly working ferry crossings. The most famous directions: Baku - Aktau, Makhachkala - Aktau, Baku - Turkmenbashi. Through the Don, Volga and Volga-Don Canal, the Caspian Lake is connected with Sea of Azov.
Local residents catch sturgeon, bream, carp, pike perch, and sprat in the waters of the sea. People here are engaged in seal fishing and caviar production. Unfortunately, in this reservoir you can also encounter illegal sturgeon fishing and caviar extraction. Popular are the flounder and mullet caught here, different types shrimp. Sturgeon fish here feed on the Nereis worm, which was specially brought to the Caspian Sea. The “Five” countries of the Caspian Sea, washed by its waters, specially organize fish breeding and spawning farms.
In the northern shallow waters, sturgeon are most abundant, especially near Russia. It is worth listing the sterlet, beluga, sturgeon, thorn, and stellate sturgeon that live there. Many people like to catch carp species: bream, roach, asp. Many catfish, grass carp, and silver carp live here. There are more small inhabitants in the Caspian Sea than large ones. In the south of the lake, herring winter and spawn. Fishing in the Caspian Sea is allowed all year round, except April - May. It is allowed to use fishing rods, spinning rods, donks and other devices.
The Astrakhan region is the region chosen most for fishing in Russia. Fishing for some sturgeon is temporarily prohibited here, but you can catch pike, catfish, and pike perch. In spring, sabrefish and rudd often bite here. In Kalmykia, industrial fishing is carried out in Lagan. Large specimens of carp are found here. Often fishermen have to spend the night right in their boats. The water in these areas is very clear, so spearfishing is used.
Holidays on the Caspian Sea
Sandy beaches, mineral waters, healing mud of the Caspian coast are a good help for treatment and relaxation. The tourism industry and resorts here are not as developed as on the Black Sea, but there are many people who want to relax. It is at a fairly popular level in Azerbaijan, Turkmenistan, Iran and Russian Dagestan. Azerbaijan has developed a resort area near Baku. Only local residents relax here; foreign tourists lack a sufficient level of service and good advertising.
The Russian coast is mainly located in Dagestan. Potential tourists are afraid to come here. But the beauty of the Caspian Sea is simply mesmerizing! It is here that you can admire the waves with gray scallops, the bitter salinity of the dark water, and small shells on the shore. Holidays on the Caspian Sea are often considered exotic. After all, it's more of a lake...
The increased salinity of water in the Caspian Sea increases its medicinal properties. The water in the reservoir warms up early, so you can easily come here in May. In September you can have a great time, because the water stays at +21°C.
What are the conditions for holidays in Dagestan near the sea? Here the coast is covered with yellow velvety sea sand. The water of the Caspian Sea warms up faster than in the Black Sea, because the former is much shallower. The swimming season here begins in mid-May. The beauty of the Caspian coast is enhanced picturesque mountains, which is not far from Derbent. Here you can admire the oldest marine fossils, which were raised to a thousand-meter height by gas formation. After this, many caves were formed here, about which there are various legends. Many local residents come to these places to worship higher powers.
During the Soviet period, Dagestan was a holiday destination for tourists from different parts of the USSR. Holidays here are cheaper than on the Black Sea coast, the sea is warmer and Sandy shore more pleasant.
The Caspian coast in Dagestan has many kilometers of beaches: Makhachkala, Samur, Manas, Kayakent. On their territory there are recreation centers (150 units), boarding houses, sanatoriums, and children's camps. You can book rooms not only in state hotels and boarding houses, but also in large and small private hotels. Renting a single room here costs from 500 to 1,000 rubles, a double room - 700-1,500 rubles, luxury apartments - 1,500-2,000 rubles.
If you get tired of swimming in the sea, then in Dagestan you can go to the snow-capped peaks. Rafting enthusiasts can go to fast mountain rivers. Guides offer interesting excursions to historical places.
Not far from the Caspian coast, it is worth seeing the capital of Dagestan - Makhachkala. This beautiful and well-equipped city has a highly developed infrastructure. Makhachkala residents are trying to attract as many tourists as possible to their city and are building a resort area " Cote d'Azur" This development occupies 300 hectares of area.
The South Dagestan coast with its center in Derbent is the most attractive place for tourism. This area has a temperate continental climate, being located in the subtropics. The territory is rich in citrus fruits, figs, pomegranates, almonds, walnuts, grapes and other crops.
No less colorful is the city of Izberbash. There is beautiful nature here with clean mountain-sea air, rich in the aroma of forests that grow low on the foothills of the Greater Caucasus. The sandy beach can be replaced by a walk to mineral springs, among which there are geothermal ones that help restore health.
Rosstourism has taken measures to develop cruise holidays in the Caspian Sea. Not only domestic Russian routes, but also international ones have been thought out. Sea cruises are often connected to the Volga route. For such events, very good ships are needed, because there are often storms on the Caspian Sea.
Another direction sea holiday in the Caspian Sea is health-improving and therapeutic. The local sea air helps to overcome many ailments. Many sanatoriums have been built on the seashore in Dagestan. People get healthier here mineral waters, mud, healing climate. It cannot do without health and sports tourism. Leisure quite popular today. For those interested, extreme, ski, and eco-tourism are offered. You can be sure that the Caspian Sea and its coastal areas deserve to be visited.
, Kura
42° N. w. 51° east d. HGIOLCaspian Sea- the largest closed body of water on Earth, which can be classified as the largest closed lake, or as a full-fledged sea, due to its size, and also because its bed is composed of oceanic-type crust. Located at the junction of Europe and Asia. The water in the Caspian Sea is brackish, from 0.05 ‰ near the mouth of the Volga to 11-13 ‰ in the southeast. The water level is subject to fluctuations, according to 2009 data it was 27.16 m below sea level. The area of the Caspian Sea is currently approximately 371,000 km², the maximum depth is 1025 m.
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Etymology
Geographical position
The Caspian Sea is located at the junction of Europe and Asia. The length of the 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° in .d.).
According to physical and geographical conditions, the Caspian Sea is conventionally divided into three parts - the Northern Caspian (25% of the sea area), the Middle Caspian (36%) and the Southern Caspian (39%). The conditional border between the Northern and Middle Caspian runs along the line Chechen Island - Cape Tyub-Karagan, between the Middle and Southern Caspian - along the line Chilov Island - Cape Gan-Gulu.
Coast
The territory adjacent to the Caspian Sea is called the Caspian region.
Peninsulas
- Absheron Peninsula, located on the western coast of the Caspian Sea on the territory of Azerbaijan, at the northeastern end of the Greater Caucasus, on its territory the cities of Baku and Sumgait are located
- Mangyshlak, located on east coast Caspian Sea, on the territory of Kazakhstan, on its territory is the city of Aktau
Islands
There are about 50 large and medium-sized islands in the Caspian Sea with a total area of approximately 350 square kilometers.
Most large islands:
Bays
Large bays:
Kara-Bogaz-Gol
Off the east coast is salt Lake Kara-Bogaz-Gol, until 1980, was a bay-lagoon of the Caspian Sea, connected to it by a narrow strait. In 1980, a dam was built separating Kara-Bogaz-Gol from the Caspian Sea, and in 1984 a culvert was built, after which the level of Kara-Bogaz-Gol dropped by several meters. In 1992, the strait was restored, through which water flows from the Caspian Sea to Kara-Bogaz-Gol and evaporates there. Every year, 8-10 cubic kilometers of water (according to other sources - 25 cubic kilometers) and about 15 million tons of salt flow into Kara-Bogaz-Gol from the Caspian Sea.
Rivers flowing into the Caspian Sea
130 rivers flow into the Caspian Sea, of which 9 rivers have a delta-shaped mouth. Large rivers flowing into the Caspian Sea are Volga, Terek, Sulak, Samur (Russia), Ural, Emba (Kazakhstan), Kura (Azerbaijan), Atrek (Turkmenistan), Sefidrud (Iran). Largest river, flowing into the Caspian Sea - the Volga, its average annual flow is 215-224 cubic kilometers. The Volga, Ural, Terek, Sulak and Emba provide up to 88-90% of the annual flow into the Caspian Sea.
Basin of the Caspian Sea
Coastal states
According to the Intergovernmental Economic Conference of the Caspian States:
The Caspian Sea washes the shores of five coastal states:
Cities on the Caspian Sea coast
On the Russian coast there are cities - Lagan, Makhachkala, Kaspiysk, Izberbash, Dagestan Lights and the most Southern City Russia Derbent. port city Astrakhan is also considered to be part of the Caspian Sea, which, however, is not located on the shores of the Caspian Sea, but in the Volga delta, 60 kilometers from the northern coast of the Caspian Sea.
Physiography
Area, depth, volume of water
The area and volume of water in the Caspian Sea varies significantly depending on fluctuations in water levels. At a water level of −26.75 m, the area is approximately 371,000 square kilometers, the volume of water is 78,648 cubic kilometers, which is approximately 44% of the world's lake water reserves. The maximum depth of the Caspian Sea is in the South Caspian depression, 1025 meters from its surface level. In terms of maximum depth, the Caspian Sea is second only to Baikal (1620 m) and Tanganyika (1435 m). The average depth of the Caspian Sea, calculated from the bathygraphic curve, is 208 meters. At the same time, the northern part of the Caspian Sea is shallow, its maximum depth does not exceed 25 meters, and the average depth is 4 meters.
Water level fluctuations
Vegetable world
The flora of the Caspian Sea and its coast is represented by 728 species. The predominant plants in the Caspian Sea are algae - blue-green, diatoms, red, brown, characeae and others, and flowering plants - zoster and ruppia. In origin, the flora is predominantly of Neogene age, however, some plants were brought into the Caspian Sea by humans deliberately, or on the bottoms of ships.
Story
Origin
The Caspian Sea is of oceanic origin - its bed is composed of oceanic-type crust. 13 million l. n. the resulting Alps separated the Sarmatian Sea from the Mediterranean. 3.4 - 1.8 million l. n. (Pliocene) there was the Akchagyl Sea, the sediments of which were studied by N. I. Andrusov. It was originally formed on the site of the dried-up Pontic Sea, from which Lake Balakhanskoe (in the southern Caspian Sea) remained. The Akchagyl transgression gave way to the Domashkin regression (a drop of 20 - 40 m from the level of the Akchagyl basin), accompanied by a strong desalination of sea waters, which is due to the cessation of the flow of sea (ocean) waters from the outside. After a short Domashkin regression at the beginning of the Quaternary period (Eopleistocene), the Caspian Sea is almost restored in the form of the Absheron Sea, which covers the Caspian Sea and floods the territories of Turkmenistan and the Lower Volga region. At the beginning of the Absheron transgression, the basin turns into a brackish water body. The Absheron Sea exists from 1.7 to 1 million years ago. The beginning of the Pleistocene in the Caspian Sea was marked by a long and deep Turkic regression (-150 m to −200 m), corresponding to the Matuyama-Brunhes magnetic reversal (0.8 million years ago). The water mass of the Turkyan basin with an area of 208 thousand km² was concentrated in the South Caspian and part of the Middle Caspian basins, between which there was a shallow strait in the area of the Absheron threshold. In the early Neopleistocene, after the Turkic regression, there existed an isolated Early Baku and a Late Baku (level up to 20 m) drainage basins (about 400 thousand years ago). The Vened (Mishovdag) regression divided the Baku and Urundzhik (middle Neopleistocene, up to −15 m) transgressions at the end of the early - beginning of the late Pleistocene (basin area - 336 thousand km²). Between the marine Urundzhik and Khazar deposits, a large deep Cheleken regression (up to −20 m) was noted, corresponding to the optimum of the Likhvin interglacial (350-300 thousand years ago). In the Middle Neopleistocene there were basins: early Khazar (200 thousand years ago), early Khazar middle (level up to 35-40 m) and early Khazar late. In the late Neopleistocene, there was an isolated late Khazar basin (level up to −10 m, 100 thousand years ago), after which a small Chernoyarsk regression occurred in the second half - the end of the Middle Pleistocene (thermoluminescent dates 122-184 thousand years ago), in in turn, replaced by the Hyrcanian (Gyurgyan) basin.
The deep long-term Atelian regression of the mid-Late Pleistocene at the initial stage had a level of −20 - −25 m, at the maximum stage −100 - −120 m, at the third stage - −45 - −50 m. At the maximum, the basin area is reduced to 228 thousand km² . After Atel regression (−120 - −140 m), approx. 17 thousand l. n. The early Khvalynian transgression began - up to + 50 m (the Manych-Kerch Strait was functioning), which was interrupted by the Eltonian regression. The Early Khvalyn II basin (level up to 50 m) was replaced at the beginning of the Holocene by a short-term Enotaev regression (from −45 to −110 m), coinciding in time with the end of the Preboreal and the beginning of the Boreal. The Enotayevskaya regression gave way to the Late Khvalynskaya transgression (0 m). The Late Khvalynian transgression was replaced in the Holocene (ca. 9-7 thousand years ago or 7.2-6.4 thousand years ago) by the Mangyshlak regression (from −50 to −90 m). The Mangyshlak regression gave way during the first phase of interglacial cooling and humidification (Atlantic period) to the New Caspian transgression. The New Caspian basin was brackish-water (11-13 ‰), warm-water and isolated (level up to −19 m). At least three cycles of transgressive-regressive phases have been recorded in the development of the Novo-Caspian basin. The Dagestan (Gousan) transgression previously belonged to the initial stage of the New Caspian era, but the absence of a leading New Caspian form in its sediments Cerastoderma glaucum (Cardium edule) gives grounds for identifying it as an independent transgression of the Caspian Sea. The Izberbash regression, separating the Dagestan and the Neo-Caspian transgressions of the Caspian Sea itself, occurred between 4.3 and 3.9 thousand years ago. Judging by the structure of the Turali section (Dagestan) and radiocarbon analysis data, transgressions were noted twice - about 1900 and 1700 years ago.
Anthropological and cultural history of the Caspian Sea
Shipping
Shipping is developed in the Caspian Sea. There are ferry crossings on the Caspian Sea, in particular, Baku - Turkmenbashi, Baku - Aktau, Makhachkala - Aktau. The Caspian Sea has a shipping connection with the Sea of Azov through the Volga, Don and Volga-Don Canal rivers.
Fishing and seafood production
Fishing (sturgeon, bream, carp, pike perch, sprat), caviar production, as well as seal fishing. More than 90 percent of the world's sturgeon catch occurs in the Caspian Sea. In addition to industrial mining, illegal mining of sturgeon and their caviar flourishes in the Caspian Sea.
Recreational resources
Natural environment of the Caspian coast with sandy beaches, mineral waters and healing mud in the coastal zone creates good conditions for relaxation and treatment. At the same time, in terms of the degree of development of resorts and the tourism industry, the Caspian coast is noticeably inferior to the Black Sea coast of the Caucasus. At the same time, in recent years, the tourism industry has been actively developing on the coasts of Azerbaijan, Iran, Turkmenistan and Russian Dagestan. Azerbaijan is actively developing resort area in the Baku region. At the moment, a world-class resort has been created in Amburan, another modern tourist complex is being built in the area of the village of Nardaran, and holidays in the sanatoriums of the villages of Bilgah and Zagulba are very popular. A resort area is also being developed in Nabran, in northern Azerbaijan. However, high prices in general low level service and lack of advertising lead to the fact that there are almost no foreign tourists. The development of the tourism industry in Turkmenistan is hampered by a long-term policy of isolation, in Iran - Sharia laws, due to which mass holidays of foreign tourists on the Caspian coast of Iran are impossible.
Ecological problems
Ecological problems The Caspian Sea is associated with water pollution as a result of oil production and transportation on the continental shelf, the flow of pollutants from the Volga and other rivers flowing into the Caspian Sea, the life of coastal cities, as well as the flooding of individual objects due to rising levels of the Caspian Sea. Predatory production of sturgeon and their caviar, rampant poaching lead to a decrease in the number of sturgeon and to forced restrictions on their production and export.
Legal status
After the collapse of the USSR, the division of the Caspian Sea has long been and still remains the subject of unresolved disagreements related to the division of Caspian shelf resources - oil and gas, as well as biological resources. Negotiations took place for a long time between Caspian states on the status of the Caspian Sea - Azerbaijan, Kazakhstan and Turkmenistan insisted on dividing the Caspian along the median line, Iran insisted on dividing the Caspian by one fifth between all Caspian states.
In relation to the Caspian Sea, the key is the physical-geographical circumstance that it is a closed inland body of water that does not have a natural connection with the World Ocean. Accordingly, the norms and concepts of international maritime law, in particular, the provisions of the 1982 UN Convention on the Law of the Sea, should not automatically apply to the Caspian Sea. Based on this, in relation to the Caspian Sea it would be unlawful to apply such concepts as “territorial sea”, “exclusive economic zone”, “continental shelf”, etc.
The current legal regime of the Caspian Sea was established by the Soviet-Iranian treaties of 1921 and 1940. These treaties provide for freedom of navigation throughout the sea, freedom of fishing with the exception of ten-mile national fishing zones and a ban on vessels flying the flag of non-Caspian states sailing in its waters.
Negotiations on the legal status of the Caspian Sea are currently ongoing.
Delineation of sections of the Caspian seabed for subsoil use
The Russian Federation concluded an agreement with Kazakhstan on delimiting the bottom of the northern part of the Caspian Sea in order to exercise sovereign rights to subsoil use (dated July 6, 1998 and the Protocol thereto dated May 13, 2002), an agreement with Azerbaijan on delimiting adjacent areas of the bottom of the northern part of the Caspian Sea (dated September 23, 2002), as well as the trilateral Russian-Azerbaijani-Kazakh agreement on the junction point of the demarcation lines of adjacent sections of the Caspian Sea bottom (dated May 14, 2003), which established geographical coordinates dividing lines limiting the areas of the seabed within which the parties exercise their sovereign rights in the field of exploration and production of mineral resources.
Not all of the countries located on the shores of the Caspian Sea can be listed.
Countries on the Caspian Sea
Caspian Sea is the largest inland body of water on our planet by area. It also has no churn. The Caspian Sea is classified in different ways: as the world's largest lake and as a full-fledged sea. Its surface area is 371,000 km 2 (143,200 mi 2) and its volume is 78,200 km 3. Maximum depth 1025 m. Sea salinity is about 1.2% (12 g/l). The water level in the sea constantly fluctuates due to tectonic movements and high temperature air. Today it is 28 m below sea level.
Even the ancient inhabitants who inhabited the coast of the Caspian Sea perceived it as a real ocean. It seemed to them limitless and very large. The word “Caspian” comes from the language of these peoples.
What countries are located on the shores of the Caspian Sea?
Sea waters wash the shores of 5 coastal states. This:
- Russia. The coastal zone covers Kalmykia, Dagestan and the Astrakhan region in the northwest and west. The length of the coastline is 695 km.
- Kazakhstan. The coastal zone covers the east, north and northeast of the state. The length of the coastline is 2320 km.
- Turkmenistan. The coastal zone covers the southeast of the country. The length of the coastline is 1200 km.
- Iran. The coastal zone covers the southern part of the state. The length of the coastline is 724 km.
- Azerbaijan. The coastal zone covers the southwest of the country. The length of the coastline is 955 km.
In addition, this body of water is the main object of the International Society, since it has huge reserves of natural gas and oil. The Caspian Sea is only 700 miles long, but it contains six basins with hydrocarbon reserves. Most of them have not been mastered by humans.
The coastline of the Caspian Sea is estimated at approximately 6,500 - 6,700 kilometers, with islands - up to 7,000 kilometers. The shores of the Caspian Sea in most of its territory are low-lying and smooth. In the northern part, the coastline is indented by water streams and islands of the Volga and Ural deltas, the banks are low and swampy, and the water surface in many places is covered with thickets. The east coast is dominated by limestone shores adjacent to semi-deserts and deserts. The most winding shores are on the western coast in the area of the Absheron Peninsula and on the eastern coast in the area of the Kazakh Gulf and Kara-Bogaz-Gol.
Peninsulas of the Caspian Sea
Large peninsulas of the Caspian Sea:
* Agrakhan Peninsula
* The Absheron Peninsula, located on the western coast of the Caspian Sea on the territory of Azerbaijan, at the northeastern end of the Greater Caucasus, on its territory the cities of Baku and Sumgait are located
* Buzachi
* Mangyshlak, located on the eastern coast of the Caspian Sea, on the territory of Kazakhstan, on its territory is the city of Aktau.
* Miankale
* Tub-Karagan
There are about 50 large and medium-sized islands in the Caspian Sea with a total area of approximately 350 square kilometers.
Largest islands:
* Ashur-Ada
* Garasu
*Hum
* Dash
* Zira (island)
* Zyanbil
* Cure Dasha
* Khara-Zira
* Sengi-Mugan
* Chechen (island)
* Chygyl
Large bays of the Caspian Sea:
* Agrakhan Bay,
* Komsomolets (bay),
* Mangyshlak,
* Kazakh (bay),
* Turkmenbashi (bay) (formerly Krasnovodsk),
* Turkmen (bay),
* Gizilagach,
* Astrakhan (bay)
* Gyzlar
* Hyrcanus (formerly Astarabad) and
* Anzeli (formerly Pahlavi).
Rivers flowing into the Caspian Sea
130 rivers flow into the Caspian Sea, of which 9 rivers have a delta-shaped mouth. Large rivers flowing into the Caspian Sea are the Volga, Terek (Russia), Ural, Emba (Kazakhstan), Kura (Azerbaijan), Samur (Russian border with Azerbaijan), Atrek (Turkmenistan) and others. The largest river flowing into the Caspian Sea is the Volga, its average annual flow is 215-224 cubic kilometers. The Volga, Ural, Terek and Emba provide up to 88 - 90% of the annual runoff of the Caspian Sea.
Basin of the Caspian Sea
The area of the Caspian Sea basin is approximately 3.1 - 3.5 million square kilometers, which is approximately 10 percent of the world's closed land area. water pools. The length of the Caspian Sea basin from north to south is about 2500 kilometers, from west to east - about 1000 kilometers. The Caspian Sea basin covers 9 states - Azerbaijan, Armenia, Georgia, Iran, Kazakhstan, Russia, Uzbekistan, Turkey and Turkmenistan.
Coastal states
The Caspian Sea washes the shores of five coastal states:
* Russia (Dagestan, Kalmykia and Astrakhan region) - in the trap and north-west, the length of the coastline is 695 kilometers
* Kazakhstan - in the north, northeast and east, coastline length 2320 kilometers
* Turkmenistan - in the southeast, the length of the coastline is 1200 kilometers
* Iran - in the south, coastline length - 724 kilometers
* Azerbaijan - in the southwest, coastline length 955 kilometers
Cities on the Caspian Sea coast
The largest city and port on the Caspian Sea is Baku, the capital of Azerbaijan, which is located in the southern part of the Absheron Peninsula and has a population of 2,070 thousand people (2003). Other major Azerbaijani Caspian cities are Sumgait, which is located in the northern part of the Absheron Peninsula, and Lankaran, which is located near the southern border of Azerbaijan. To the South-East of the Absheron Peninsula, the oil workers’ village of Neftyanye Kamni is located, the buildings of which stand on artificial islands, overpasses and technological sites.
Large Russian cities- the capital of Dagestan, Makhachkala, and the southernmost city of Russia, Derbent, are located on the western coast of the Caspian Sea. Astrakhan is also considered a port city of the Caspian Sea, which, however, is not located on the shores of the Caspian Sea, but in the Volga delta, 60 kilometers from the northern coast of the Caspian Sea.
On east coast On the Caspian Sea there is a Kazakh city - the port of Aktau, in the north in the Ural delta, 20 km from the sea, the city of Atyrau is located, south of Kara-Bogaz-Gol on the northern shore of the Krasnovodsk Bay - the Turkmen city of Turkmenbashi, former Krasnovodsk. Several Caspian cities are located on the southern (Iranian) coast, the largest of them is Anzeli.
Area, depth, volume of water
The area and volume of water of the Caspian Sea varies significantly depending on fluctuations in water levels. At a water level of −26.75 m, the area was approximately 392,600 square kilometers, the volume of water was 78,648 cubic kilometers, which is approximately 44 percent of the world's lake water reserves. The maximum depth of the Caspian Sea is in the South Caspian depression, 1025 meters from its surface level. In terms of maximum depth, the Caspian Sea is second only to Baikal (1620 m) and Tanganyika (1435 m). The average depth of the Caspian Sea, calculated from the bathygraphic curve, is 208 meters. At the same time, the northern part of the Caspian Sea is shallow, its maximum depth does not exceed 25 meters, and the average depth is 4 meters.
Water level fluctuations
The water level in the Caspian Sea is subject to significant fluctuations. According to modern science, over the past 3 thousand years the amplitude of changes in the water level of the Caspian Sea has been 15 meters. Instrumental measurements of the level of the Caspian Sea and systematic observations of its fluctuations have been carried out since 1837, during which time the most high level water level was registered in 1882 (-25.2 m), the lowest was in 1977 (-29.0 m), since 1978 the water level has increased and in 1995 reached −26.7 m, since 1996 Again, there was a tendency towards a decrease in the level of the Caspian Sea. Scientists associate the reasons for changes in the water level of the Caspian Sea with climatic, geological and anthropogenic factors.
Water temperature
Water temperature is subject to significant latitudinal changes, most clearly expressed in winter, when the temperature varies from 0-0.5 °C at the ice edge in the north of the sea to 10-11 °C in the south, that is, the difference in water temperature is about 10 °C. For shallow water areas with depths less than 25 m, the annual amplitude can reach 25-26 °C. On average, the water temperature off the western coast is 1-2 °C higher than that on the eastern coast, and in the open sea the water temperature is 2-4 °C higher than on the coasts. Based on the nature of the horizontal structure of the temperature field in the annual cycle of variability, three can be distinguished: time intervals in the upper 2-meter layer. From October to March, the water temperature increases in the southern and eastern regions, which is especially clearly visible in the Middle Caspian. Two stable quasi-latitudinal zones can be distinguished, where temperature gradients are increased. This is, firstly, the border between the Northern and Middle Caspian, and, secondly, between the Middle and Southern. At the ice edge, in the northern frontal zone, the temperature in February-March increases from 0 to 5 °C, in the southern frontal zone, in the area of the Absheron threshold, from 7 to 10 °C. During this period, the least cooled waters are in the center of the South Caspian Sea, which form a quasi-stationary core.
In April-May, the area of minimum temperatures moves to the Middle Caspian Sea, which is associated with faster heating of waters in the shallow northern part of the sea. True, at the beginning of the season in the northern part of the sea a large amount of heat is spent on melting ice, but already in May the temperature here rises to 16-17 °C. In the middle part the temperature at this time is 13-15 °C, and in the south it increases to 17-18 °C.
Spring warming of water evens out horizontal gradients, and the temperature difference between coastal areas and open sea does not exceed 0.5 °C. Warming up of the surface layer, starting in March, disrupts the homogeneity in the temperature distribution with depth. In June-September, horizontal homogeneity in the temperature distribution in the surface layer is observed. In August, which is the month of greatest warming, the water temperature throughout the sea is 24-26 °C, and in the southern regions it rises to 28 °C. In August, the water temperature in shallow bays, for example, in Krasnovodsk, can reach 32 °C. The main feature of the water temperature field at this time is upwelling. It is observed annually along the entire eastern coast of the Middle Caspian and partially penetrates even into the Southern Caspian.
The rise of cold deep waters occurs with varying intensity as a result of the influence of prevailing summer season northwest winds. The wind in this direction causes the outflow of warm surface waters from the coast and the rise of colder waters from the intermediate layers. Upwelling begins in June, but it reaches its greatest intensity in July-August. As a result, a decrease in temperature is observed on the surface of the water (7-15 °C). Horizontal temperature gradients reach 2.3 °C at the surface and 4.2 °C at a depth of 20 m.
The source of upwelling gradually shifts from 41-42° north. latitude in June, to 43-45° north. latitude in September. Summer upwelling is of great importance for the Caspian Sea, radically changing the dynamic processes in the deep-water area. In open areas of the sea, in late May - early June, the formation of a temperature jump layer begins, which is most clearly expressed in August. Most often it is located between horizons of 20 and 30 m in the middle part of the sea and 30 and 40 m in the southern part. Vertical temperature gradients in the shock layer are very significant and can reach several degrees per meter. In the middle part of the sea, due to the surge off the eastern coast, the shock layer rises close to the surface.
Since in the Caspian Sea there is no stable baroclinic layer with a large reserve of potential energy similar to the main thermocline of the World Ocean, then with the cessation of the prevailing winds causing upwelling and with the beginning of autumn-winter convection in October-November, a rapid restructuring of temperature fields to the winter regime occurs. In the open sea, the water temperature in the surface layer drops in the middle part to 12-13 °C, in the southern part to 16-17 °C. In the vertical structure, the shock layer is eroded due to convective mixing and disappears by the end of November.
Water composition
The salt composition of the waters of the closed Caspian Sea differs from the oceanic one. There are significant differences in the ratios of concentrations of salt-forming ions, especially for waters in areas directly influenced by continental runoff. The process of metamorphization of sea waters under the influence of continental runoff leads to a decrease in the relative content of chlorides in the total amount of salts of sea waters, an increase in the relative amount of carbonates, sulfates, calcium, which are the main components in the chemical composition of river waters. The most conservative ions are potassium, sodium, chlorine and magnesium. The least conservative are calcium and bicarbonate ions. In the Caspian Sea, the content of calcium and magnesium cations is almost two times higher than in the Sea of Azov, and the sulfate anion is three times higher. The salinity of water changes especially sharply in the northern part of the sea: from 0.1 units. psu in the estuary areas of the Volga and Ural up to 10-11 units. psu on the border with the Middle Caspian.
Mineralization in shallow salty bays-kultuks can reach 60-100 g/kg. In the Northern Caspian, during the entire ice-free period from April to November, a salinity front of a quasi-latitudinal location is observed. The greatest desalination, associated with the spread of river flow across the sea, is observed in June. On the formation of the salinity field in the Northern Caspian Sea big influence exerts a wind field. In the middle and southern parts of the sea, salinity fluctuations are small. Basically it is 11.2-12.8 units. psu, increasing in the southern and eastern directions. With depth, salinity increases slightly (by 0.1-0.2 units psu).
In the deep-sea part of the Caspian Sea, in the vertical profile of salinity, characteristic deflections of isohalines and local extrema are observed in the area of the eastern continental slope, which indicate processes of bottom sliding of waters salinizing in the eastern shallow waters of the South Caspian. The magnitude of salinity also strongly depends on sea level and (which is interconnected) on the volume of continental runoff.
Bottom relief
The relief of the northern part of the Caspian Sea is a shallow undulating plain with banks and accumulative islands, the average depth of the Northern Caspian Sea is about 4-8 meters, the maximum does not exceed 25 meters. The Mangyshlak threshold separates the Northern Caspian from the Middle Caspian. The Middle Caspian is quite deep, the water depth in the Derbent depression reaches 788 meters. The Absheron threshold separates the Middle and Southern Caspian Seas. The Southern Caspian Sea is considered deep-water; the water depth in the South Caspian depression reaches 1025 meters from the surface of the Caspian Sea. Shell sands are widespread on the Caspian shelf, deep-sea areas are covered with silty sediments, and in some areas there is an outcrop of bedrock.
Climate
The climate of the Caspian Sea is continental in the northern part, temperate in the middle and subtropical in the southern part. In winter, the average monthly temperature of the Caspian Sea varies from −8 −10 in the northern part to +8-10 in the southern part, in summer - from +24-25 in the northern part to +26-27 in the southern part. The maximum temperature recorded on the east coast was 44 degrees.
The average annual precipitation is 200 millimeters per year, ranging from 90-100 millimeters in the arid eastern part to 1,700 millimeters along the southwestern subtropical coast. Evaporation of water from the surface of the Caspian Sea is about 1000 millimeters per year, the most intense evaporation in the area of the Absheron Peninsula and in the eastern part of the South Caspian Sea is up to 1400 millimeters per year.
On the territory of the Caspian Sea, winds often blow, their average annual speed is 3-7 meters per second, and northern winds predominate in the wind rose. In the autumn and winter months, winds become stronger, with wind speeds often reaching 35-40 meters per second. The most windy areas are the Absheron Peninsula and the environs of Makhachkala - Derbent, where the highest wave was recorded - 11 meters.
Currents
Water circulation in the Caspian Sea is related to runoff and winds. Since most of the drainage occurs in the Northern Caspian Sea, northern currents predominate. An intense northern current carries water from the Northern Caspian along the western coast to the Absheron Peninsula, where the current divides into two branches, one of which moves further along the western coast, the other goes to the Eastern Caspian.
Animal world
The fauna of the Caspian Sea is represented by 1809 species, of which 415 are vertebrates. 101 species of fish are registered in the Caspian world, where most of the world's sturgeon reserves are concentrated, as well as freshwater fish such as roach, carp, and pike perch. The Caspian Sea is the habitat of fish such as carp, mullet, sprat, kutum, bream, salmon, perch, and pike. The Caspian Sea is also home to a marine mammal, the Caspian seal. Since March 31, 2008, 363 dead seals have been found on the coast of the Caspian Sea in Kazakhstan.
Vegetable world
The flora of the Caspian Sea and its coast is represented by 728 species. Among the plants in the Caspian Sea, the predominant algae are blue-green, diatoms, red, brown, characeae and others, and among the flowering plants - zoster and ruppia. In origin, the flora is predominantly of Neogene age, but some plants were brought into the Caspian Sea by humans deliberately or on the bottoms of ships.
Origin of the Caspian Sea
The Caspian Sea is of oceanic origin - its bed is composed of oceanic-type crust. It was formed approximately 10 million years ago, when the closed Sarmatian Sea, which lost contact with the world's oceans approximately 70 million years ago, was divided into two parts - the "Caspian Sea" and the Black Sea.
Anthropological and cultural history Caspian Sea
Finds in the Khuto u cave south coast The Caspian Sea indicates that man lived in these areas approximately 75 thousand years ago. The first mentions of the Caspian Sea and the tribes living on its coast are found in Herodotus. Around the V-II centuries. BC e. Saka tribes lived on the Caspian coast. Later, during the period of settlement of the Turks, in the period of the IV-V centuries. n. e. Talysh tribes (Talysh) lived here. According to ancient Armenian and Iranian manuscripts, Russians sailed the Caspian Sea from the 9th - 10th centuries.
Research of the Caspian Sea
Research of the Caspian Sea was started by Peter the Great, when, on his order, an expedition was organized in 1714-1715 under the leadership of A. Bekovich-Cherkassky. In the 1820s, hydrographic research was continued by I. F. Soyomov, and later by I. V. Tokmachev, M. I. Voinovich and other researchers. At the beginning of the 19th century, instrumental surveys of the shores were carried out by I. F. Kolodkin, in the mid-19th century. - instrumental geographical survey under the direction of N. A. Ivashintsev. Since 1866, for more than 50 years, expeditionary research on the hydrology and hydrobiology of the Caspian Sea was carried out under the leadership of N. M. Knipovich. In 1897, the Astrakhan Research Station was founded. In the first decades of Soviet power, geological research by I.M. Gubkin and other Soviet geologists was actively carried out in the Caspian Sea, mainly aimed at searching for oil, as well as research into the study of water balance and level fluctuations in the Caspian Sea.
Mining of oil and gas
Many oil and gas fields are being developed in the Caspian Sea. Proven oil resources in the Caspian Sea are about 10 billion tons, total oil and gas condensate resources are estimated at 18-20 billion tons.
Oil production in the Caspian Sea began in 1820, when the first oil well was drilled on the Absheron shelf. In the second half of the 19th century, oil production began on an industrial scale on the Absheron Peninsula, and then in other territories.
In addition to oil and gas production, salt, limestone, stone, sand, and clay are also mined on the coast of the Caspian Sea and the Caspian shelf.
Shipping
Shipping is developed in the Caspian Sea. There are ferry crossings on the Caspian Sea, in particular, Baku - Turkmenbashi, Baku - Aktau, Makhachkala - Aktau. The Caspian Sea has a shipping connection with the Sea of Azov through the Volga, Don and Volga-Don Canal rivers.
Fishing and seafood production
Fishing (sturgeon, bream, carp, pike perch, sprat), caviar production, as well as seal fishing. More than 90 percent of the world's sturgeon catch occurs in the Caspian Sea. In addition to industrial mining, illegal fishing of sturgeon and their caviar flourishes in the Caspian Sea.
Recreational resources
The natural environment of the Caspian coast with sandy beaches, mineral waters and healing mud in the coastal zone creates good conditions for recreation and treatment. At the same time, in terms of the degree of development of resorts and the tourism industry, the Caspian coast noticeably loses Black Sea coast Caucasus. At the same time, in recent years, the tourism industry has been actively developing on the coasts of Azerbaijan, Iran, Turkmenistan and Russian Dagestan.
Ecological problems
Environmental problems of the Caspian Sea are associated with water pollution as a result of oil production and transportation on the continental shelf, the flow of pollutants from the Volga and other rivers flowing into the Caspian Sea, the life of coastal cities, as well as the flooding of individual objects due to rising levels of the Caspian Sea. Predatory production of sturgeon and their caviar, rampant poaching lead to a decrease in the number of sturgeon and to forced restrictions on their production and export.
Border dispute over the status of the Caspian Sea
After the collapse of the USSR, the division of the Caspian Sea has long been and still remains the subject of unresolved disagreements related to the division of Caspian shelf resources - oil and gas, as well as biological resources. For a long time, negotiations were ongoing between the Caspian states on the status of the Caspian Sea - Azerbaijan, Kazakhstan and Turkmenistan insisted on dividing the Caspian along the median line, Iran insisted on dividing the Caspian by one-fifth between all Caspian states. In 2003, Russia, Azerbaijan and Kazakhstan signed an agreement on the partial division of the Caspian Sea along the median line.
Coordinates: 42.622596 50.041848
