Caspian Sea

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Caspian Sea
Caspian Sea.jpg
Satellite image of the Caspian Sea
Geographical location Azerbaijan , Kazakhstan , Iran , Russia , Turkmenistan
Tributaries Volga , Urals , Kura , Terek
Drain drainless
Places on the shore Aqtau , Astrakhan , Baku , Bandar Anzali , Makhachkala , Rāmsar , Turkmenbaşy
Coordinates 41 °  N , 51 °  E Coordinates: 41 °  N , 51 °  E
Caspian Sea (Asia)
Caspian Sea
Depth below sea level 28  m below sea level
surface 386,400  km²dep1
length 1200 km
width 435 km
volume 78,700 km³dep1
Maximum depth 995 m, lake bottom 1023  m below sea level
Middle deep 184 m


largest lake on earth,
second deepest natural depression,
oil production, rich in fish

Template: Infobox Lake / Maintenance / EVIDENCE AREA Template: Infobox Lake / Maintenance / EVIDENCE LAKE WIDTH Template: Infobox Lake / Maintenance / EVIDENCE VOLUME Template: Infobox Lake / Maintenance / EVIDENCE MAX DEPTH Template: Infobox Lake / Maintenance / EVIDENCE -MED DEPTH

The Caspian Sea , and the Caspian Sea called ( Azerbaijani Xəzər dənizi , Kazakh теңізі Каспий , Persian دریای خزر / دریای مازندران, DMG Daryā-ye Ḫazar / Daryā-ye Māzandarān , Russian Каспийское море , Turkmen Kaspi deňzi ), is the largest lake on earth. The salt lake is an endorheic body of water , i.e. without a natural connection to the oceans .

The Caspian Sea lies within the great Aralo-Caspian lowland in western Asia and in the far east of Europe. In the north it borders on Russia and Kazakhstan , in the east on Turkmenistan , in the south on Iran and in the west on Azerbaijan .

Status under international law

Countries bordering the Caspian Sea

Since the Caspian Sea is not a sea in the legal sense, it is not subject to the 1994 Convention on the Law of the Sea .

On August 12, 2018, the heads of state and government of the neighboring states of Azerbaijan , Iran , Kazakhstan , Russia and Turkmenistan agreed in a framework agreement in Aktau (Kazakhstan) that the Caspian Sea should be used under its own legal status - neither as a lake nor as a sea. The agreement has yet to be ratified by the parliaments. In addition, the division of the seabed needs to be specified.

Previously, contracts from 1921 and 1940 regulated shipping and fishing only between Iran and the Soviet Union . These defined the Caspian Sea as inland waters with the right of common use . The states of Azerbaijan, Kazakhstan and Turkmenistan, which emerged with the collapse of the Soviet Union , have seen themselves at a disadvantage since then. They sought extraction rights for crude oil and natural gas as well as the right to lay pipelines for this purpose. Russia was important in the agreement that no armed forces from third countries - especially NATO - get access. Due to US sanctions, Iran was keen to complete the negotiations that began in 1996.


The oldest cultural evidence can be found on inscriptions on Assyrian pottery and call a "southern sea". Hekataios of Miletus mentions it in the 6th century BC. BC as "Caspian and Hyrcanic Sea"; the first popular name refers to the Caspi tribe who lived on the southwestern bank of the Caspian Caucasus, in today's Azerbaijan, the second refers to the bank near Hyrkanien , a landscape on today's Iranian and southern Turkmen coast. Other ancient names are the ethnonyms "Alban", "Joshgun" and "Hyrcan". The changing history of settlement led to numerous other names such as B. the Tatar designation "Ag Deniz" (White Sea, cf. also Khazar Sea and mix-ups, e.g. "Blue Sea" in old Russian documents with the Aral Sea) or "Kasar Danizi" in the Turkish-speaking Khazars who lived in the 5th Settled northwest to the 10th century. In total, different peoples have given the lake around 70 different names, including less established terms such as "Baku Sea" in the 14th and 15th centuries according to the economic importance of the city of Baku at that time.


Bathymetric map (1863, Tiefen in Saschen )

The Caspian Sea, which lies in an extensive and up to 1023 m deep natural depression , is located, among other things, between the dry part of the great Caspian Depression in the north, the Kazak steppes in the northeast, the great lowlands of Turan in the east, the Elburs in the south and the Caucasus in the west. Azerbaijan (length of coast: approx. 800 km), Iran (length of coast: 750 km), Kazakhstan (length of coast: 1894 km), Russia (length of coast: approx. 960 km) and Turkmenistan (length of coast: 1768 km) border it.

The Caspian Sea is - depending on the definition - part of the border between Europe and Asia and thus divides Eurasia into two continents. For the course of this border, see under Inner Eurasian border .

The area of ​​the Caspian Sea is 386,400 km², making it the largest land-enclosed water area on earth or its largest lake . The area of ​​the Caspian Sea roughly corresponds to the area of ​​Germany and Belgium or the Baltic Sea without the Kattegat . Its north-south extension is 1200 km, its west-east extension is 435 km (on average 300 km). While the large northern part is only about 6 m deep on average, its deepest point in the south is 995 m. Because its water surface is 28 m below sea level , this maximum depth is 1023 m below sea level , making it the second deepest natural depression on earth after Lake Baikal , the bottom of which is 1182 m below sea level .

The Caspian Sea has no natural connection with the oceans. It is therefore a lake and is called " sea " only because of its size and the salinity of the water. A previously common name was Caspisee. However, there is a navigable connection via the Volga , the Volga-Don Canal and the Don via the Sea of ​​Azov to the Black Sea , via the Volga, the Volga-Baltic Sea Canal , Lake Onega and the Neva to the Baltic Sea and branching off from Lake Onega via the White Sea Baltic Canal to the White Sea .

History of origin

The Caspian Sea, like the Black Sea and Aral Sea, is a remnant of the Paratethys , an inland sea that stretched from Western Europe to Central Asia during the Oligocene and most of the Neogene . Towards the end of the Miocene , a border with the Black Sea developed, and since the beginning of the Pliocene there has been a series of strong water level fluctuations, which greatly varied the size. When the water level was low, the Caspian Sea shrank to a lake in the deepest areas in the south; when the water level was high, it was reunited with the Black Sea. This happened for the last time at the end of the ice ages, when the ice masses of the Siberian glaciers thawed and the Manytn lowlands were flooded. To the east, a connection to the Aral Sea was established in the Aralo-Caspian lowlands .

There was never a direct connection to the ocean, because at the time of its connection with the Caspian Sea, according to popular belief, the Black Sea was separated from the Mediterranean.

Paleogeography of the western Tethys region and its surroundings during the Oligocene . The Paratethys ended in southern Europe and was replaced by the Mediterranean Sea, and you can also see the outlines of the Black Sea , the Caspian Sea and the Aral Sea.

Changes in the water level

In the 20th century, the water surface decreased dramatically from the early 1930s to the 1980s; At the beginning of this period, the lake area is said to have been around 420,000 km². The sinking of the lake level took place mainly in the years 1930–1941 and 1970–1977 at a rate of 16 and 14 cm per year, respectively, a total of around three meters, since the beginning of the records and its provisional high in 1896 even by 3.5 m . The water masses that were fed into the lake by the Volga , Urals and Kura were not sufficient at that time to maintain its water content; the withdrawal of water for irrigation purposes was enormous at its few tributaries and the evaporation that arose on the huge water surface caused its content and thus its size to constantly shrink. Part of the responsibility was also the construction of the large Volga barrages, which increased the area of ​​evaporation of the Volga so that the Volga, as the main tributary, could feed in less water.

The Kara Bogas Bay , a formerly very shallow but large eastern bulge of the Caspian Sea, was sealed off by a dam at the narrowest junction in 1980 because evaporation was particularly high in this dry, hot area. After the dam was built, the lagoon dried up completely and turned into an environmentally dangerous salt desert. Since the installation of locks between 1985 and 1991 did not improve the situation significantly, the dam was removed in 1992.

Between 1978 and 1994 the lake level rose steadily and intensely at an annual rate of 14 cm to 40 cm. During this time, this led to extensive flooding of the mainland in a width of 5–25 km and over a length of 1500 km. This flooded 2 million hectares of land. The damage was estimated at around 12 billion US dollars, affecting a million people.

Beach at Chezer Schahr ( Māzandarān Province , Iran )
The Caspian Sea near Baku (Azerbaijan)
The Caspian Sea in the Māzandarān Province (Iran)
The Caspian Sea near Ramsar (Iran). Remnants of privacy screens that divided the beaches between men and women.
The Caspian Sea near Türkmenbaşy ( Turkmenistan )

The rise in the water level by over two and a half meters led to a temporary maximum in 1995 and has since stagnated, apart from minor changes. The reasons for the strong fluctuations are widely discussed. The most likely explanation lies in changes in the water balance. It is significantly influenced by the Volga (it is responsible for about 80 percent of the water inflow) and by the extensive evaporation areas v. a. in the north and in Kara Bogas Bay. The statistically significant correlation with secular changes in drainage through the Volga was investigated by Rodionov in 1994. The water balance is influenced by numerous other causes that have been responsible for fluctuations of up to six meters over the past 2500 years. For Ramiz M. Mammedov from the Geographic Institute of the Academy of Sciences in Baku it is clear that of the three factors geology, man and climate, the climate factor plays the most important role. Seasonal level fluctuations of around 40 cm are not included in the investigation of the long-term effects, but are significant in the short-term threat to coastal industrial plants. The following factors are mentioned for the development of the water balance and its further effects:

  • The water withdrawal by humans is rather low. It can explain the drop in sea level in the 1970s, but not the extremely rapid rise afterwards.
  • Climate changes are responsible for the decline in the level in the 1930s. They are "clearly due to a decrease in winter precipitation and the associated reduced amount of water in the Volga". When it comes to precipitation, a distinction should be made between the relatively low direct entry into the sea and climatic influences from precipitation in the catchment area of ​​all tributaries, mainly the Volga; The current climate change is therefore causing concern, its effects on the Caspian Sea have not yet been adequately researched.
  • The long-term fluctuations in the general weather situation are influenced by the changing activity of the sunspots and by changes in air pressure, which cause global changes in the amount of precipitation in the area of ​​the continental tributaries.
  • The increasing pollution of the sea surface, especially with an oil film, makes evaporation considerably more difficult and could have fatal consequences for the water cycle.
  • Forty atomic bomb tests in the Astrakhan region are a legacy from the Soviet era of the 1950s to the 1990s; there, deep underground caverns with "huge" water supplies have been opened, which drain into the Caspian Sea. The data on the previous and expected amounts of water are still secret.
  • The plate displacement in the tectonically active region can influence the water level, but the influence of the morphology of the sea floor due to an earthquake of 10 to 15 percent due to the horizontal direction is very small.

The rise in the water level has placed the neighboring countries with the need to protect the settlements and industrial facilities in the flooded areas. The areas of intensive oil and gas production and industrial landfills with dangerous goods are particularly threatened. The prediction from 2002, which predicted a further increase of 2.30 m by 2010, has apparently not come true. Russian hydrometeorologists, who are based on known data from climate history, predicted an increase of 4.5 to 5 meters by 2050, which would particularly affect the coastal plain of Azerbaijan. However, the interaction of the many different factors for reliable forecasts has not yet been adequately researched.


There are numerous islands in the Caspian Sea. Most are small and unpopulated, but there are some populated ones as well. Many of the islands near Azerbaijan are significant because of their oil reserves.

The Bulla Island off the coast of Azerbaijan has significant oil deposits. The same goes for Pirallahı Island . The first oil drilling in the Caspian Sea took place here and one of the first oil discoveries in Azerbaijan was also made here.

Nargin , the largest island in Baku Bay , is a former Soviet military base. Ashūradeh is located at the eastern end of the Miankaleh Peninsula northeast of the Gorgan Bay near the Iranian coast. Ashuradeh was separated from the peninsula by a canal.

Various islands, especially near Azerbaijan, have suffered enormous environmental damage from oil production, for example Dasch Sirja , although seals still live there.

In the northeast of the Caspian Sea are the Tjuleni Islands (Seal Islands).

The island of Chechnya and Seal Island are located off the coast of Dagestan .

Some islands are located off the coast of the Volga Delta and belong to Kalmykia and Astrakhan Oblast , or to the Atyrau region in Kazakhstan.

The islands that belong to Russia, such as Verkhny Oseredok , are located in the border zone of the Russian Federation and cannot be entered.

Natural resources

In Baku , in particular, there are very large reserves of oil and natural gas under the sea floor . Geologists suspect between 15 and 50 billion barrels of oil on the bottom and on the coasts of the Caspian Sea. Optimistic estimates are up to 100 billion barrels, which should represent a value of five trillion US dollars.

In the Kara-Bogas bay salt is mined.


The Caspian Sea is one of the largest tributaries

Surname Length
Catchment area
Flow rate
(m³ / s)
Atrak 669 27,300 9.2 Iran, Turkmenistan
Emba 712 40,400 17.5 Kazakhstan
Kuma 802 33,500 10 Russia
Kura 1,364 218.906 575 Turkey, Georgia, Azerbaijan
Samur 213 7,330 75 Russia, Azerbaijan
Sefid Rud * 670 13,450 157 Iran
Sulak 144 15,200 176 Russia
Terek 623 43,200 305 Georgia, Russia
Ural 2,428 244.280 297 Russia, Kazakhstan
Volga 3,530 1,360,000 8,064 Russia

* White River , also Sepid Rud or Kisil Usen called

Ports and cities

Surname Residents location
Aqtau 0181,526 Kazakhstan
Astara (Azerbaijan) 0017,100 Azerbaijan
Astara (Iran) 0045,935 Iran
Astrakhan 0520.339 Russia
Atyrau 0196.494 Kazakhstan
Babolsar 0053,684 Iran
Baku 2,181,800 Azerbaijan
Bandar Anzali 0114.105 Iran
Bandar-e Torkaman 0049,059 Iran
Derbent 0119,200 Russia
Fort Shevchenko 0004,888 Kazakhstan
Isberbash 0055,646 Russia
Kaspiysk 0100.129 Russia
Lenkoran 0048,400 Azerbaijan
Makhachkala 0572.076 Russia
Nouschahr 0043,635 Iran
Sumgait 0333,600 Azerbaijan
Türkmenbaschy 0073,803 Turkmenistan


In the north, where the two main tributaries, the Volga and Urals, confluence, the salinity is very low; towards the south, where there are hardly any significant tributaries, it rises: the maximum, at over 30%, was found in the salt deposits in the Kara-Bogas Bay ( Kara-Bogas-Gol ) in Turkmenistan . On average, the salt content is 1.1 to 1.3%, which is around a third of the concentration in the oceans.


About 150 species of fish live in the Caspian Sea, mainly freshwater fish despite the brackish water . The various sturgeons and numerous fish species imported for fishing purposes are of particular economic importance . A culinary specialty of the Caspian Sea is the sturgeon, from which caviar is obtained. There are also plenty of z. T. endemic herring relatives and wild carp . The Caspian seal is an endemic seal to the Caspian Sea.

Fish species of the Caspian Sea
Carp fish
Perch relatives


  • Gundula Bahro: The Ecological Crisis of the Caspian Sea and the Caspi Region. Page 161 ff. With references in: Ernst Giese, Gundula Bahro, Dirk Betke: Environmental destruction in arid regions of Central Asia (West and East Turkestan). Causes, effects, measures. Franz Steiner Verlag, Stuttgart 1998.
  • V. A. Zubakov: History and Causes of Variations in the Caspian Sea Level: the Miopliocene, 7.1-1.95 Million Years Ago. In: Water Resources. 28/2001, pp. 249-256, ISSN  0097-8078
  • H. J. Dumont: The Caspian Lake: History, biota, structure, and function. In: Limnology and Oceanography , 43 (1), 1998, 44–52 (available online) (PDF; 1.3 MB)
  • Zhenis Kembayev: The legal situation of the Caspian Sea (Summary: The Legal Status of the Caspian Sea). In: Journal of Foreign Public Law and International Law, 68 (4), 2008, 1027-1055.
  • Igor S. Zonn, Andrey G. Kostianoy, Aleksey N. Kosarev, Michael Glantz: The Caspian Sea Encyclopedia . Springer Verlag, Berlin, Heidelberg 2010.

Web links

Commons : Caspian Sea  - Collection of images, videos and audio files
Wiktionary: Caspian Sea  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. Caspian Environment Program ( Memento from January 16, 2013 in the Internet Archive )
  2. Duden .
  3. ^ Caspian Sea: Five countries sign deal to end dispute. In: BBC . August 12, 2018. Retrieved August 12, 2018 .
  4. Neighboring states agree on the future of the Caspian Sea. In: Spiegel Online . August 12, 2018. Retrieved August 12, 2018 .
  5. a b Caspian etymology on the Heydar Aliyev Foundation website , accessed January 31, 2018 (aze.)
  6. cf. Blue Sea in Brockhaus' Kleines Konversations-Lexikon, fifth edition, volume 1. Leipzig 1911., p. 219.
  7. History of the capital Baku -, accessed on January 7, 2019
  8. The Brockhaus from 1888 gives the area at 439,864 km².
  9. a b Project description (English, web archive)
  10. a b c d Uwe Schulte: Is the Caspian Sea drowning? Deutsche Apothekerzeitung (DAZ) 2008, No. 51, p. 108, December 18, 2008
  11. a b Bernhard Matuschak: Capers of nature. The daily newspaper, July 22, 2002
  12. CRS Report for Congress ( Memento from January 31, 2012 in the Internet Archive )
  13. Safiyeh Haghani, Suzanne Leroy AG: Recent avulsion history of Sefidrud, southwest of the Caspian Sea . In: Quaternary International . June 27, 2018, ISSN  1040-6182 , doi : 10.1016 / j.quaint.2018.06.034 ( [accessed July 11, 2019]).
  14. Petru Banaescu: Zoogeography of Fresh Waters . Volume 2, AULA, Wiesbaden 1992, ISBN 3-89104-482-8 (English)
  15. Fishspecies in Caspian Sea (Engl.)