Caucasus The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historically ...

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grasslands, ...

Central Asia Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...

Southern Russia Southern Russia or the South of Russia (russian: Юг России, ''Yug Rossii'') is a colloquial term for the southernmost geographic portion of European Russia generally covering the Southern Federal District and the North Caucasian Federal ...

Eastern Europe Eastern Europe is a subregion of the Europe, European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural, and socio-economic connotations. The vast majority of the region is covered by Russ ...

Western Asia Western Asia, West Asia, or Southwest Asia, is the westernmost subregion of the larger geographical region of Asia, as defined by some academics, UN bodies and other institutions. It is almost entirely a part of the Middle East, and includes Ana ...

Garabogazköl The Garabogazköl (also spelt Kara-Bogaz-Gol; "Black Strait Lake"), or Garabogazköl Aylagy ("Black Strait Lake Bay"), is a shallow, highly-saline water-filled depression in the northwestern corner of Turkmenistan. It forms a lagoon of the Caspian ...

salinity Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...

seawater Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has appro ...

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

Turkmenistan Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the sout ...

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised g ...

inflow Inflow may refer to: * Inflow (hydrology), the water entering a body of water * Inflow (meteorology) Inflow is the flow of a fluid into a large collection of that fluid. Within meteorology, inflow normally refers to the influx of warmth and moi ...

Volga The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the List of rivers of Europe#Rivers of Europe by length, longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Cas ...

seabed The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...

Lake Baikal Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the Repu ...

Transcaucasia The South Caucasus, also known as Transcaucasia or the Transcaucasus, is a geographical region on the border of Eastern Europe and Western Asia, straddling the southern Caucasus Mountains. The South Caucasus roughly corresponds to modern Arme ...

Strabo Strabo''Strabo'' (meaning "squinty", as in strabismus) was a term employed by the Romans for anyone whose eyes were distorted or deformed. The father of Pompey was called "Pompeius Strabo". A native of Sicily so clear-sighted that he could see ...

Caucasus Albania Caucasian Albania is a modern exonym for a former state located in ancient times in the Caucasus: mostly in what is now Azerbaijan (where both of its capitals were located). The modern endonyms for the area are ''Aghwank'' and ''Aluank'', among t ...

Albania Albania ( ; sq, Shqipëri or ), or , also or . officially the Republic of Albania ( sq, Republika e Shqipërisë), is a country in Southeastern Europe. It is located on the Adriatic and Ionian Seas within the Mediterranean Sea and shares ...

Caspian Gates The Gates of Alexander were a legendary barrier supposedly built by Alexander the Great in the Caucasus to keep the uncivilized barbarians of the north (typically associated with Gog and Magog in medieval Christian and Islamic writings) from i ...

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

Qazvin Qazvin (; fa, قزوین, , also Romanized as ''Qazvīn'', ''Qazwin'', ''Kazvin'', ''Kasvin'', ''Caspin'', ''Casbin'', ''Casbeen'', or ''Ghazvin'') is the largest city and capital of the Province of Qazvin in Iran. Qazvin was a capital of the ...

Khazars The Khazars ; he, כּוּזָרִים, Kūzārīm; la, Gazari, or ; zh, 突厥曷薩 ; 突厥可薩 ''Tūjué Kěsà'', () were a semi-nomadic Turkic people that in the late 6th-century CE established a major commercial empire coverin ...

Khwarezmia Khwarazm (; Old Persian: ''Hwârazmiya''; fa, خوارزم, ''Xwârazm'' or ''Xârazm'') or Chorasmia () is a large oasis region on the Amu Darya river delta in western Central Asia, bordered on the north by the (former) Aral Sea, on the ea ...

classical antiquity Classical antiquity (also the classical era, classical period or classical age) is the period of cultural history between the 8th century BC and the 5th century AD centred on the Mediterranean Sea, comprising the interlocking civilizations of ...

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

Turkmenistan Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the sout ...

Armenia Armenia (), , group=pron officially the Republic of Armenia,, is a landlocked country in the Armenian Highlands of Western Asia.The UNbr>classification of world regions places Armenia in Western Asia; the CIA World Factbook , , and ''Ox ...

Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a list of transcontinental countries, transcontinental country located mainly on the Anatolia, Anatolian Peninsula in Western Asia, with ...

Uzbekistan Uzbekistan (, ; uz, Ozbekiston, italic=yes / , ; russian: Узбекистан), officially the Republic of Uzbekistan ( uz, Ozbekiston Respublikasi, italic=yes / ; russian: Республика Узбекистан), is a doubly landlocked cou ...

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

Paratethys Sea The Paratethys sea, Paratethys ocean, Paratethys realm or just Paratethys was a large shallow inland sea that stretched from the region north of the Alps over Central Europe to the Aral Sea in Central Asia. Paratethys was peculiar due to its pal ...

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

granite Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies undergro ...

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised g ...

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 During warm and dry climatic periods, the landlocked sea almost dried up, depositing evaporitic sediments like

halite Halite (), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, p ...

that were covered by wind-blown deposits and were sealed off as an evaporite sink when cool, wet climates refilled the basin. (Comparable evaporite beds underlie the

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...

.) Due to the current inflow of fresh water in the north, the Caspian Sea water is almost fresh in its northern portions, getting more

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

toward the south. It is most saline on the Iranian shore, where the catchment basin contributes little flow. Currently, the mean salinity of the Caspian is one third that of Earth's oceans. The

Garabogazköl The Garabogazköl (also spelt Kara-Bogaz-Gol; "Black Strait Lake"), or Garabogazköl Aylagy ("Black Strait Lake Bay"), is a shallow, highly-saline water-filled depression in the northwestern corner of Turkmenistan. It forms a lagoon of the Caspian ...

embayment, which dried up when water flow from the main body of the Caspian was blocked in the 1980s but has since been restored, routinely exceeds oceanic salinity by a factor of 10.

Geography

The Caspian Sea is the largest inland body of water in the world by area and accounts for 40 to 44% of the total lacustrine waters of the world, and covers an area larger than

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. The coastlines of the Caspian are shared by

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...

, Iran,

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

, Russia, and

Turkmenistan Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the sout ...

. The Caspian is divided into three distinct physical regions: the Northern, Middle, and Southern Caspian. The Northern–Middle boundary is the

Mangyshlak Mangyshlak or Mangghyshlaq Peninsula ( kk, Маңғыстау түбегі, translit=Mañğystau tübegı; russian: Полуостров Мангышла́к, translit=Poluostrov Mangyshlák) is a large peninsula located in western Kazakhstan. It ...

Threshold, which runs through

Chechen Island , image_name = , image_caption = , image_size = , map_image = Caspian5CHN.png , map_caption = Location of Chechen Island , location = Caspian Sea , coordinates = , area_km2 = 55 , length_km = ...

and Cape Tiub-Karagan. The Middle–Southern boundary is the

Apsheron Threshold The Apsheron Sill, Absheron Sill, Apsheron Ridge or Apsheron Threshold is a major northwest–southeast trending bathymetric high that runs for about 250 km across the whole of the Caspian Sea from Baku in Azerbaijan to the Cheleken Peninsula in Tu ...

, a

sill Sill may refer to: * Sill (dock), a weir at the low water mark retaining water within a dock * Sill (geology), a subhorizontal sheet intrusion of molten or solidified magma * Sill (geostatistics) * Sill (river), a river in Austria * Sill plate, a ...

of tectonic origin between the Eurasian continent and an oceanic remnant, that runs through Zhiloi Island and Cape Kuuli. The

Garabogazköl The Garabogazköl (also spelt Kara-Bogaz-Gol; "Black Strait Lake"), or Garabogazköl Aylagy ("Black Strait Lake Bay"), is a shallow, highly-saline water-filled depression in the northwestern corner of Turkmenistan. It forms a lagoon of the Caspian ...

Bay is the saline eastern inlet of the Caspian, which is part of Turkmenistan and at times has been a lake in its own right due to the isthmus that cuts it off from the Caspian. Differences between the three regions are dramatic. The Northern Caspian only includes the Caspian shelf, and is very shallow; it accounts for less than 1% of the total water volume with an average depth of only . The sea noticeably drops off towards the Middle Caspian, where the average depth is . The Southern Caspian is the deepest, with oceanic depths of over , greatly exceeding the depth of other regional seas, such as the

Persian Gulf The Persian Gulf ( fa, خلیج فارس, translit=xalij-e fârs, lit=Gulf of Persis, Fars, ), sometimes called the ( ar, اَلْخَلِيْجُ ٱلْعَرَبِيُّ, Al-Khalīj al-ˁArabī), is a Mediterranean sea (oceanography), me ...

. The Middle and Southern Caspian account for 33% and 66% of the total water volume, respectively. The northern portion of the Caspian Sea typically freezes in the winter, and in the coldest winters ice forms in the south as well. Over 130 rivers provide inflow to the Caspian, the

Volga River The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the List of rivers of Europe#Rivers of Europe by length, longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Cas ...

being the largest. A second affluent, the

Ural River The Ural (russian: Урал, ), known before 1775 as Yaik (russian: Яик, ba, Яйыҡ, translit=Yayıq, ; kk, Жайық, translit=Jaiyq, ), is a river flowing through Russia and Kazakhstan in the continental border between Europe and Asia ...

, flows in from the north, and the Kura River from the west. In the past, the

Amu Darya The Amu Darya, tk, Amyderýa/ uz, Amudaryo// tg, Амударё, Amudaryo ps, , tr, Ceyhun / Amu Derya grc, Ὦξος, Ôxos (also called the Amu, Amo River and historically known by its Latin language, Latin name or Greek ) is a major rive ...

(Oxus) of Central Asia in the east often changed course to empty into the Caspian through a now-desiccated riverbed called the

Uzboy River The Uzboy (sometimes rendered Uzboj) was a distributary of the Amu Darya which flowed through the northwestern part of the Karakum Desert of Turkmenistan until the 17th century, when it abruptly dried up, eliminating the agricultural population t ...

, as did the

Syr Darya The Syr Darya (, ),, , ; rus, Сырдарья́, Syrdarjja, p=sɨrdɐˈrʲja; fa, سيردريا, Sirdaryâ; tg, Сирдарё, Sirdaryo; tr, Seyhun, Siri Derya; ar, سيحون, Seyḥūn; uz, Sirdaryo, script-Latn/. historically known ...

farther north. The Caspian has several small islands, primarily located in the north with a collective land area of roughly . Adjacent to the North Caspian is the Caspian Depression, a low-lying region below

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised g ...

. The

Central Asia Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...

n

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grasslands, ...

s stretch across the northeast coast, while the

Caucasus mountains The Caucasus Mountains, : pronounced * hy, Կովկասյան լեռներ, : pronounced * az, Qafqaz dağları, pronounced * rus, Кавка́зские го́ры, Kavkázskiye góry, kɐfˈkasːkʲɪje ˈɡorɨ * tr, Kafkas Dağla ...

hug the western shore. The

biomes A biome () is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader ...

to both the north and east are characterized by cold, continental deserts. Conversely, the climate to the southwest and south are generally warm with uneven elevation due to a mix of highlands and

mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arise ...

s; the drastic changes in climate alongside the Caspian have led to a great deal of

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...

in the region. The Caspian Sea has numerous islands near the coasts, but none in the deeper parts of the sea. Ogurja Ada is the largest island. The island is long, with gazelles roaming freely on it. In the North Caspian, the majority of the islands are small and uninhabited, like the Tyuleniy Archipelago, an

Important Bird Area An Important Bird and Biodiversity Area (IBA) is an area identified using an internationally agreed set of criteria as being globally important for the conservation of bird populations. IBA was developed and sites are identified by BirdLife Int ...

(IBA).

Climate

The climate of the Caspian Sea is variable, with the cold desert climate (BWk),

cold semi-arid climate A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...

(BSk), and

humid continental climate A humid continental climate is a climatic region defined by Russo-German climatologist Wladimir Köppen in 1900, typified by four distinct seasons and large seasonal temperature differences, with warm to hot (and often humid) summers and freezing ...

(Dsa, Dfa) being present in the northern portions of the Caspian Sea, while the

Mediterranean climate A Mediterranean climate (also called a dry summer temperate climate ''Cs'') is a temperate climate sub-type, generally characterized by warm, dry summers and mild, fairly wet winters; these weather conditions are typically experienced in the ...

(Csa) and

humid subtropical climate A humid subtropical climate is a zone of climate characterized by hot and humid summers, and cool to mild winters. These climates normally lie on the southeast side of all continents (except Antarctica), generally between latitudes 25° and 40° ...

(Cfa) are present in the southern portions of the Caspian Sea.

Hydrology

The Caspian has characteristics common to both seas and lakes. It is often listed as the world's largest lake, although it is not

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

: the 1.2% salinity classes it with brackish water bodies. It contains about 3.5 times as much water, by volume, as all five of North America's

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...

combined. The

Volga River The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the List of rivers of Europe#Rivers of Europe by length, longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Cas ...

(about 80% of the inflow) and the

Ural River The Ural (russian: Урал, ), known before 1775 as Yaik (russian: Яик, ba, Яйыҡ, translit=Yayıq, ; kk, Жайық, translit=Jaiyq, ), is a river flowing through Russia and Kazakhstan in the continental border between Europe and Asia ...

discharge into the Caspian Sea, but it has no natural outflow other than by

evaporation Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. High concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when humidi ...

. Thus the Caspian

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

is a closed basin, with its own sea level history that is independent of the

eustatic Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised g ...

level of the world's oceans. The sea level of the Caspian has fallen and risen, often rapidly, many times over the centuries. Some Russian historians claim that a

medieval In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the Post-classical, post-classical period of World history (field), global history. It began with t ...

rising of the Caspian, perhaps caused by the

Amu Darya The Amu Darya, tk, Amyderýa/ uz, Amudaryo// tg, Амударё, Amudaryo ps, , tr, Ceyhun / Amu Derya grc, Ὦξος, Ôxos (also called the Amu, Amo River and historically known by its Latin language, Latin name or Greek ) is a major rive ...

changing its inflow to the Caspian from the 13th century to the 16th century, caused the coastal towns of Khazaria, such as Atil, to flood. In 2004, the water level was below

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised g ...

. Over the centuries, Caspian Sea levels have changed in synchrony with the estimated discharge of the Volga, which in turn depends on rainfall levels in its vast catchment basin. Precipitation is related to variations in the amount of North Atlantic depressions that reach the interior, and they in turn are affected by cycles of the

North Atlantic oscillation The North Atlantic Oscillation (NAO) is a weather phenomenon over the North Atlantic Ocean of fluctuations in the difference of atmospheric pressure at sea level (SLP) between the Icelandic Low and the Azores High. Through fluctuations in the ...

. Thus levels in the Caspian Sea relate to atmospheric conditions in the North Atlantic, thousands of kilometres to the northwest. The last short-term sea-level cycle started with a sea-level fall of from 1929 to 1977, followed by a rise of from 1977 until 1995. Since then smaller oscillations have taken place. A study by the Azerbaijan Academy of Sciences estimated that the level of the sea was dropping by more than six centimetres per year due to increased evaporation due to rising temperatures caused by

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

.

Environmental degradation

The

Volga River The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the List of rivers of Europe#Rivers of Europe by length, longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Cas ...

, the longest river in Europe, drains 20% of the European land area and is the source of 80% of the Caspian's inflow. Heavy development in its lower reaches has caused numerous unregulated releases of chemical and biological pollutants. The UN Environment Programme warns that the Caspian "suffers from an enormous burden of pollution from oil extraction and refining, offshore oil fields, radioactive wastes from nuclear power plants and huge volumes of untreated sewage and industrial waste introduced mainly by the Volga River". The magnitude of

fossil fuel A fossil fuel is a hydrocarbon-containing material formed naturally in the Earth's crust from the remains of dead plants and animals that is extracted and burned as a fuel. The main fossil fuels are coal, oil, and natural gas. Fossil fuels m ...

extraction and transport activity in the Caspian also poses a risk to the environment. The island of

Vulf Vulf, or Volf , and also known as Dash Zira (Azeri: ''Daş Zirə'') or Kichik Zira ''(Kiçik Zirə)'', is an island of Azerbaijan, in the Caspian Sea. The word "Zira" originated in the Arabic word "Jazīra", meaning "island". Vulf is tiny and uni ...

off

Baku Baku (, ; az, Bakı ) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. Baku is located below sea level, which makes it the lowest lying national capital in the world a ...

, for example, has suffered ecological damage as a result of the petrochemical industry; this has significantly decreased the number of species of marine birds in the area. Existing and planned oil and gas pipelines under the sea further increase the potential threat to the environment. The high concentration of

mud volcano A mud volcano or mud dome is a landform created by the eruption of mud or slurries, water and gases. Several geological processes may cause the formation of mud volcanoes. Mud volcanoes are not true igneous volcanoes as they do not produce lava ...

es under the Caspian Sea were thought to be the cause of a fire that broke out 75 kilometers from

Baku Baku (, ; az, Bakı ) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. Baku is located below sea level, which makes it the lowest lying national capital in the world a ...

on July 5, 2021. The State oil company of Azerbaijan

SOCAR The State Oil Company of Azerbaijan Republic ( az, Azərbaycan Respublikası Dövlət Neft Şirkəti), largely known as SOCAR is fully state-owned national oil and gas company headquartered in Baku, Azerbaijan. The company produces oil and na ...

said preliminary information indicated it was a mud volcano which spewed both mud and flammable gas. It is calculated that during the 21st century, the water level of the Caspian Sea will decrease by 9–18 m (30–60 ft) due to the acceleration of evaporation due to

global warming In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

and the process of

desertification Desertification is a type of land degradation in drylands in which biological productivity is lost due to natural processes or induced by human activities whereby fertile areas become increasingly arid. It is the spread of arid areas caused by ...

. On October 23, 2021, Kazakhstan President

Kassym-Jomart Tokayev Kassym-Jomart Kemeluly Tokayev ( kk, Қасым-Жомарт Кемелұлы Тоқаев, Qasym-Jomart Kemelūly Toqaev ; born 17 May 1953) is a Kazakh politician and diplomat who is currently serving as the President of Kazakhstan since 12 J ...

signed the Protocol for the Protection of the Caspian Sea against Pollution from Land-based Sources in order to ensure better protection for the biodiversity of the Caspian Sea.

Flora and fauna

Flora

The rising level of the Caspian Sea between 1994 and 1996 reduced the number of habitats for rare species of aquatic vegetation. This has been attributed to a general lack of seeding material in newly formed coastal

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') a ...

s and water bodies. Many rare and endemic plant species of Russia are associated with the tidal areas of the

Volga delta The Volga Delta is the largest river delta in Europe, and occurs where Europe's largest river system, the Volga River, drains into the Caspian Sea in Russia's Astrakhan Oblast, north-east of the republic of Kalmykia. The delta is located in the ...

and riparian forests of the Samur River delta. The shoreline is also a unique refuge for plants adapted to the loose sands of the Central Asian Deserts. The principal limiting factors to successful establishment of plant species are hydrological imbalances within the surrounding deltas,

water pollution Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water ...

, and various land reclamation activities. The water level change within the Caspian Sea is an indirect reason for which plants may not get established. These affect aquatic plants of the Volga Delta, such as ''

Aldrovanda vesiculosa ''Aldrovanda vesiculosa'', commonly known as the waterwheel plant, is the sole extant species in the flowering plant genus ''Aldrovanda'' of the family Droseraceae. The plant captures small aquatic invertebrates using traps similar to those of ...

'' and the native '' Nelumbo caspica''. About 11 plant species are found in the Samur River delta, including the unique

liana A liana is a long- stemmed, woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the canopy in search of direct sunlight. The word ''liana'' does not refer to a ta ...

forests that date back to the Tertiary period. Since 2019

UNESCO The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...

has admitted the lush

Hyrcanian forests The Hyrcanian forests ( fa, جنگل های هیرکانی) are a zone of lush lowland and montane forests covering about adjoining the shores of the Caspian Sea of Iran and part of that of Azerbaijan. The forest is named after the ancient reg ...

of Mazandaran, Iran as World Heritage Site under category (ix).

Fauna

The

Caspian turtle The Caspian turtle or striped-neck terrapin (''Mauremys caspica'') is a species of turtle in the family Geoemydidae (=Bataguridae), living in the eastern Mediterranean region from southwestern former USSR and central Iran to Saudi Arabia, Bahrai ...

(''Mauremys caspica''), although found in neighboring areas, is a wholly freshwater species. The zebra mussel is native to the Caspian and

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

basins, but has become an

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

elsewhere, when introduced. The area has given its name to several species, including the Caspian gull and the Caspian tern. The

Caspian seal The Caspian seal (''Pusa caspica'', syn. ''Phoca caspica'') is one of the smallest members of the earless seal family and unique in that it is found exclusively in the brackish Caspian Sea. It lives along the shorelines, but also on the many roc ...

(''Pusa caspica'') is the only aquatic mammal

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the Caspian Sea, being one of very few seal species that live in inland waters, but it is different from those inhabiting freshwaters due to the hydrological environment of the sea. A century ago the Caspian was home to more than one million

seals Seals may refer to: * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, or "true seal" ** Fur seal * Seal (emblem), a device to impress an emblem, used as a means of a ...

. Today, fewer than 10% remain. Archeological studies of

Gobustan Rock Art Gobustan Rock Art represents flora and fauna, hunting, lifestyles, and culture of pre-historic and medieval periods of time. The carvings on the rocks illustrates primitive men, ritual dances, men with lances in their hands, animals, bull fights, ...

have identified what may be

dolphin A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the ...

s and

porpoise Porpoises are a group of fully aquatic marine mammals, all of which are classified under the family Phocoenidae, parvorder Odontoceti (toothed whales). Although similar in appearance to dolphins, they are more closely related to narwhals an ...

s, likely present in the Caspian Sea at least until the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...

or much more recent periods such as the last glacial period or

antiquity Antiquity or Antiquities may refer to: Historical objects or periods Artifacts *Antiquities, objects or artifacts surviving from ancient cultures Eras Any period before the European Middle Ages (5th to 15th centuries) but still within the histo ...

. Although the rock art on Kichikdash Mountain is assumed to be of a dolphin it might instead represent the famous

beluga sturgeon The beluga (), also known as the beluga sturgeon or great sturgeon (''Huso huso''), is a species of anadromous fish in the sturgeon family (Acipenseridae) of order Acipenseriformes. It is found primarily in the Caspian and Black Sea basins, a ...

due to its size (430 cm in length), but fossil records suggest certain ancestors of modern dolphins and whales, such as ''

Macrokentriodon ''Macrokentriodon'' is an extinct genus of giant dolphin once assigned to the paraphyletic/polyphyletic family Kentriodontidae. Remains have been found in the late Miocene (Serravallian) Choptank Formation of United States. ''Macrokentriodon'' ...

morani'' (

bottlenose dolphin Bottlenose dolphins are aquatic mammals in the genus ''Tursiops.'' They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus definitively contains two species: the common ...

s) and '' Balaenoptera sibbaldina'' (

blue whale The blue whale (''Balaenoptera musculus'') is a marine mammal and a baleen whale. Reaching a maximum confirmed length of and weighing up to , it is the largest animal known to have ever existed. The blue whale's long and slender body can ...

s) were presumably larger than their present descendants. From the same artworks,

auk An auk or alcid is a bird of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The word "auk" is derived from Icelandic ''álka'', from Old Norse ''alka'' (a ...

s, like

Brunnich's Guillemot The thick-billed murre or Brünnich's guillemot (''Uria lomvia'') is a bird in the auk family (Alcidae). This bird is named after the Danish zoologist Morten Thrane Brünnich. The very deeply black North Pacific subspecies ''Uria lomvia arra'' ...

could also have been in the sea as well, and these petroglyphs suggest marine inflow between the current Caspian Sea and the Arctic Ocean or

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

, or the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

. This is supported by the existences of current endemic, oceanic species such as lagoon cockles which was genetically identified to originate in Caspian/Black Seas regions. The sea's basin (including associated waters such as rivers) has 160 native species and

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of fish in more than 60

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

.Naseka, A.M. and Bogutskaya, N.G. (2009). "Fishes of the Caspian Sea: zoogeography and updated check-list". ''Zoosystematica Rossica'' 18(2): 295–317. About 62% of the species and subspecies are

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

, as are 4–6 genera (depending on

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

treatment). The lake proper has 115 natives, including 73 endemics (63.5%). Among the more than 50 genera in the lake proper, 3–4 are endemic: ''

Anatirostrum The duckbill pugolovka (''Anatirostrum profundorum'') is a species of gobiid fish endemic to the southern part of the Caspian Sea. It is characterized by its special flattened and elongated head that resembles a duck's bill.Brian W. CoadFreshwat ...

'', '' Caspiomyzon'', '' Chasar'' (often included in ''

Ponticola ''Ponticola'' is a genus of gobies native mostly to fresh waters of the Black Sea - Caspian Sea region in Eurasia. Some species occur in the brackish-water Black and Caspian seas themselves. It was considered to be part of the broader goby subfam ...

'') and ''

Hyrcanogobius ''Hyrcanogobius bergi'', the Volga dwarf goby, is a species of goby endemic to the Caspian Sea where it occurs in fresh, brackish and marine waters along the coast. Unusually for gobies, this species is almost a pelagic fish. This species grow ...

''. By far the most numerous families in the lake proper are gobies (35 species and subspecies),

cyprinid Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest verte ...

s (32) and

clupeid Clupeidae is a family of ray-finned fishes, comprising, for instance, the herrings, shads, sardines, hilsa, and menhadens. The clupeoids include many of the most important food fishes in the world, and are also commonly caught for production of f ...

s (22). Two particularly rich genera are ''

Alosa ''Alosa'' is a genus of fish, the river herrings, in the family (biology), family Clupeidae. Along with other genera in the subfamily Alosinae, they are generally known as shads. tp://ftp.fao.org/docrep/fao/009/ac482e/ac482e27.pdf Subfamily A ...

'' with 18 endemic species/subspecies and ''Benthophilus'' with 16 endemic species. Other examples of endemics are four species of ''Clupeonella'', ''Gobio volgensis'', two ''Rutilus'', three ''Sabanejewia'', ''Stenodus leucichthys'', two ''Salmo'', two ''Mesogobius'' and three ''Neogobius''. Most non-endemic natives are either shared with the Black Sea basin or widespread

Palearctic The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa. The realm consists of several bioregions: the Euro-Sibe ...

species such as

crucian carp The crucian carp (''Carassius carassius'') is a medium-sized member of the common carp family Cyprinidae. It occurs widely in northern European regions. Its name derives from the Low German ''karusse'' or ''karutze'', possibly from Medieval Lat ...

,

Prussian carp The Prussian carp, silver Prussian carp or Gibel carp (''Carassius gibelio''), is a member of the family Cyprinidae, which includes many other fish, such as the common carp, goldfish, and the smaller minnows. It is a medium-sized cyprinid, and d ...

,

common carp The Eurasian carp or European carp (''Cyprinus carpio''), widely known as the common carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia.Fishbase''Cyprinus carpio'' Linnaeus, 1758/ref>Arkive The ...

, common bream, common bleak,

asp Asp may refer to: Places * Asp, part of Densbüren, Aargau, Switzerland * Aspe (''Asp'' in Valencian), Alicante, Spain * Asp Lake, a lake in Minnesota Animals * Asp (fish) * Asp (snake), in antiquity, one of several venomous snakes ** ''Cera ...

,

white bream ''Blicca bjoerkna'', alternatively called the white bream or the silver bream, is a European species of freshwater fish in the family Cyprinidae. Distribution ''Blicca bjoerkna'' is distributed across most of Europe and in adjacent Western Asi ...

,

sunbleak ''Leucaspius delineatus'', known as the sunbleak, belica or moderlieschen is a species of freshwater fish in the family Cyprinidae. It is currently the only species included in genus ''Leucaspius'', whereas formerly others were included, which no ...

,

common dace The common dace (''Leuciscus leuciscus'') is a species of freshwater and brackish water ray-finned fish from the family Cyprinidae which is native to Europe but which has been introduced to other parts of the world. It is a quarry species for coa ...

, common roach,

common rudd The common rudd (''Scardinius erythrophthalmus'') is a bentho-pelagic freshwater fish, widely spread in Europe and middle Asia, around the basins of the North, Baltic, Black, Caspian and Aral seas. Identification Morphologically, this species ...

, European chub, sichel,

tench The tench or doctor fish (''Tinca tinca'') is a fresh- and brackish-water fish of the order Cypriniformes found throughout Eurasia from Western Europe including the British Isles east into Asia as far as the Ob and Yenisei Rivers. It is also ...

,

European weatherfish The weatherfish (''Misgurnus fossilis'') is a species of true loach that has a wide range in Europe and some parts of Asia. It is an omnivorous scavenger bottom feeder, using its sensitive barbels to find edible items. The diet mostly consists o ...

, wels catfish,

northern pike The northern pike (''Esox lucius'') is a species of carnivorous fish of the genus '' Esox'' (the pikes). They are typical of brackish and fresh waters of the Northern Hemisphere (''i.e.'' holarctic in distribution). They are known simply as a ...

,

burbot The burbot (''Lota lota'') is the only gadiform (cod-like) freshwater fish Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments di ...

, European perch and zander. Almost 30 non-indigenous, introduced fish species have been reported from the Caspian Sea, but only a few have become established. Six

sturgeon Sturgeon is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretace ...

species, the Russian,

bastard Bastard may refer to: Parentage * Illegitimate child, a child born to unmarried parents ** Bastard (law of England and Wales), illegitimacy in English law People People with the name * Bastard (surname), including a list of people with that na ...

,

Persian Persian may refer to: * People and things from Iran, historically called ''Persia'' in the English language ** Persians, the majority ethnic group in Iran, not to be conflated with the Iranic peoples ** Persian language, an Iranian language of the ...

,

sterlet The sterlet (''Acipenser ruthenus'') is a relatively small species of sturgeon from Eurasia native to large rivers that flow into the Black Sea, Azov Sea, and Caspian Sea, as well as rivers in Siberia as far east as Yenisei. Populations migratin ...

, starry and beluga, are native to the Caspian Sea. The last of these is arguably the largest freshwater fish in the world. The sturgeon yield roe (eggs) that are processed into caviar.

Overfishing Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in th ...

has depleted a number of the historic fisheries. In recent years, overfishing has threatened the sturgeon population to the point that environmentalists advocate banning sturgeon fishing completely until the population recovers. The high price of sturgeon caviar—more than 1,500 Azerbaijani manats (US$880 ) per kilo—allows fishermen to afford bribes to ensure the authorities look the other way, making regulations in many locations ineffective. Caviar harvesting further endangers the fish stocks, since it targets reproductive females. Extantigerturanianwksciam97

Reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...

s native to the region include the

spur-thighed tortoise The Greek tortoise (''Testudo graeca''), also known commonly as the spur-thighed tortoise, is a species of tortoise in the family Testudinidae. ''Testudo graeca'' is one of five species of Mediterranean tortoises ( genera '' Testudo'' and '' A ...

(''Testudo graeca buxtoni'') and

Horsfield's tortoise The Russian tortoise (''Testudo horsfieldii''), also commonly known as the Afghan tortoise, the Central Asian tortoise, Horsfield's tortoise, four-clawed tortoise, and the (Russian) steppe tortoise, is a threatened species of tortoise in the fam ...

. *The

Asiatic cheetah The Asiatic cheetah (''Acinonyx jubatus venaticus'') is a critically endangered cheetah subspecies currently only surviving in Iran. It once occurred from the Arabian Peninsula and the Near East to the Caspian region, Transcaucasus, Kyzylkum D ...

used to occur in the Trans-Caucasus and

Central Asia Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...

, but is today restricted to Iran.Humphreys, P., Kahrom, E. (1999)
Lion and Gazelle: The Mammals and Birds of Iran
. Images Publishing, Avon. *The Asiatic lion used to occur in the Trans-Caucasus, Iran, and possibly the southern part of

Turkestan Turkestan, also spelled Turkistan ( fa, ترکستان, Torkestân, lit=Land of the Turks), is a historical region in Central Asia corresponding to the regions of Transoxiana and Xinjiang. Overview Known as Turan to the Persians, western Turke ...

. *The Caspian tiger used to occur in northern Iran, the Caucasus and

Central Asia Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...

. *The endangered

Persian leopard ''Panthera pardus tulliana'' is a leopard subspecies native to the Iranian Plateau and surrounding areas encompassing Turkey, the Caucasus, Azerbaijan, Georgia, Armenia, Iraq, Iran, Turkmenistan, Afghanistan and possibly Pakistan. Since 2016, i ...

is found in Iran, the Caucasus and Central Asia.

History

Geology

The main geologic history locally had two stages. The first is the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

, determined by

tectonic Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents k ...

events that correlate with the closing of the Tethys Sea. The second is the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

noted for its

glaciation A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betw ...

cycles and the full run of the present Volga. During the first stage, the Tethys Sea had evolved into the Sarmatian Lake, that was created from the modern Black Sea and south Caspian, when the collision of the

Arabian peninsula The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Plate ...

with

Western Asia Western Asia, West Asia, or Southwest Asia, is the westernmost subregion of the larger geographical region of Asia, as defined by some academics, UN bodies and other institutions. It is almost entirely a part of the Middle East, and includes Ana ...

pushed up the Kopet Dag and

Caucasus Mountains The Caucasus Mountains, : pronounced * hy, Կովկասյան լեռներ, : pronounced * az, Qafqaz dağları, pronounced * rus, Кавка́зские го́ры, Kavkázskiye góry, kɐfˈkasːkʲɪje ˈɡorɨ * tr, Kafkas Dağla ...

, lasting south and west limits to the basin. This orogeneic movement was continuous, while the Caspian was regularly disconnected from the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

. In the late Pontian, a mountain arch rose across the south basin and divided it into the Khachmaz and

Lankaran Lankaran ( az, Lənkəran, ) is a city in Azerbaijan, on the coast of the Caspian Sea, near the southern border with Iran. As of 2021, the city had a population of 89,300. It is next to, but independent of, Lankaran District. The city forms a dis ...

Lakes (or early Balaxani). The period of restriction to the south basin was reversed during the Akchagylian – the lake became more than three times its size today and took again the first of a series of contacts with the Black Sea and with

Lake Aral The Aral Sea ( ; kk, Арал теңізі, Aral teñızı; uz, Орол денгизи, Orol dengizi; kaa, Арал теңизи, Aral teńizi; russian: Аральское море, Aral'skoye more) was an endorheic lake lying between Kazakh ...

. A recession of Lake Akchagyl completed stage one. surikov1906

Early settlement nearby

The earliest hominid remains found around the Caspian Sea are from Dmanisi dating back to around 1.8 Ma and yielded a number of skeletal remains of

Homo erectus ''Homo erectus'' (; meaning "upright man") is an extinct species of archaic human from the Pleistocene, with its earliest occurrence about 2 million years ago. Several human species, such as '' H. heidelbergensis'' and '' H. antecessor' ...

or Homo ergaster. More later evidence for human occupation of the region came from a number of caves in Georgia and Azerbaijan such as Kudaro and Azykh Caves. There is evidence for

Lower Palaeolithic The Lower Paleolithic (or Lower Palaeolithic) is the earliest subdivision of the Paleolithic or Old Stone Age. It spans the time from around 3 million years ago when the first evidence for stone tool production and use by hominins appears in ...

human occupation south of the Caspian from western Alburz. These are Ganj Par and

Darband Cave Darband Cave is a Lower Paleolithic site in the Gilan Province in northern Iran, located on the north side of a deep tributary canyon of the Siahrud River, a tributary of the Sefīd-Rūd River that flows into the Caspian Sea. The cave contains ...

sites.

Neanderthal Neanderthals (, also ''Homo neanderthalensis'' and erroneously ''Homo sapiens neanderthalensis''), also written as Neandertals, are an extinct species or subspecies of archaic humans who lived in Eurasia until about 40,000 years ago. While th ...

remains also have been discovered at a cave in Georgia. Discoveries in the Hotu cave and the adjacent Kamarband cave, near the town of

Behshahr Behshahr ( fa, بهشهر; formerly Ashraf and Ashraf ol Belād) is a city in Mazandaran, Iran & the capital of Behshahr County. Located on the coast of the Caspian Sea, at the foot of the Alborz, it is approximately from Sari. At the 2006 cen ...

, Mazandaran south of the Caspian in Iran, suggest human habitation of the area as early as 11,000 years ago. Ancient Greeks focused on the civilization on the south shore – they call it the (H)yr(c/k)anian Sea ( grc, Υρκανία θάλαττα, with sources noting the latter word was evolving then to today's ''Thelessa'': late grc, θάλασσα).

Chinese maximal limit

Later, in the

Tang dynasty The Tang dynasty (, ; zh, t= ), or Tang Empire, was an Dynasties in Chinese history, imperial dynasty of China that ruled from 618 to 907 AD, with an Zhou dynasty (690–705), interregnum between 690 and 705. It was preceded by the Sui dyn ...

(618-907), the sea was the western limit of the Chinese Empire.

Fossil fuel

The area is rich in fossil fuels. Oil wells were being dug in the region as early as the 10th century to reach oil "for use in everyday life, both for medicinal purposes and for heating and lighting in homes"."The Development of the Oil and Gas Industry in Azerbaijan
". SOCAR By the 16th century, Europeans were aware of the rich oil and gas deposits locally. English traders

Thomas Bannister Thomas Bannister (1799–1874) was a soldier and explorer in Western Australia. He was born in Steyning, Sussex in 1799, and arrived in Western Australia in 1829, age 30, with the rank of Captain aboard the ''Atwick'' with 3 servants from Londo ...

and Jeffrey Duckett described the area around

Baku Baku (, ; az, Bakı ) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. Baku is located below sea level, which makes it the lowest lying national capital in the world a ...

as "a strange thing to behold, for there issueth out of the ground a marvelous quantity of oil, which serveth all the country to burn in their houses. This oil is black and is called nefte. There is also by the town of Baku, another kind of oil which is white and very precious .e., petroleum">petroleum.html" ;"title=".e., petroleum">.e., petroleum""Back to the Future: Britain, Baku Oil and the Cycle of History
". SOCAR Today, oil and gas platforms abound along the edges of the sea.

Geography, geology and navigation studies

During the rule of Peter I the Great, Fedor Ivanovich Soimonov, Fedor I. Soimonov was a pioneering explorer of the sea. He was a hydrographer who charted and greatly expanded knowledge of the sea. He drew a set of four maps and wrote ''Pilot of the Caspian Sea'', the first lengthy report and modern maps. These were published in 1720 by the

Russian Academy of Sciences The Russian Academy of Sciences (RAS; russian: Росси́йская акаде́мия нау́к (РАН) ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across t ...

.

Cities

Ancient

* Hyrcania, ancient state in the north of Iran *

Sari A sari (sometimes also saree or shari)The name of the garment in various regional languages include: * as, শাৰী, xārī, translit-std=ISO * bn, শাড়ি, śāṛi, translit-std=ISO * gu, સાડી, sāḍī, translit-std= ...

, Mazandaran Province of Iran * Anzali, Gilan Province of Iran * Astara, Gilan Province of Iran * Astarabad, Golestan Province of Iran * Tamisheh, Golestan Province of Iran *

Atil, Khazaria Atil (also Itil) , was the capital of the Khazar Khaganate from the middle of the 8th century until the end of the 10th century. Known to have been situated on the Silk Road in the vicinity of the Caspian Sea, its precise location has long been ...

* Khazaran *

Baku Baku (, ; az, Bakı ) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. Baku is located below sea level, which makes it the lowest lying national capital in the world a ...

, Azerbaijan *

Derbent Derbent (russian: Дербе́нт; lez, Кьвевар, Цал; az, Дәрбәнд, italic=no, Dərbənd; av, Дербенд; fa, دربند), formerly romanized as Derbend, is a city in Dagestan, Russia, located on the Caspian Sea. It is ...

,

Dagestan Dagestan ( ; rus, Дагеста́н, , dəɡʲɪˈstan, links=yes), officially the Republic of Dagestan (russian: Респу́блика Дагеста́н, Respúblika Dagestán, links=no), is a republic of Russia situated in the North C ...

, Russia * Xacitarxan, modern-day Astrakhan

Modern

*

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

: ** Ali Abad ** Astane-ye Ashrafiye ** Astara **

Babolsar Babolsar ( fa, بابلسر, also Romanized as Bābolsar and Bābul Sar; also known as Mashhadsar (Persian: مَشهَدسَر), also Romanized as Mashhad-i-Sar and Meshed-i-Sar) is a city and capital of Babolsar County, Mazandaran Province, Ira ...

** Bandar-e Anzali ** Bandar-e-Gaz **

Bandar Torkaman Bandar Torkaman ( fa, بندرتركمن), formerly known as Bandar Shah ( fa, بَندَرِ شاه), is a city and capital of Torkaman County, Golestan Province, Iran. At the 2006 census its population was 45,045, in 9,755 families. Bandar To ...

**

Behshahr Behshahr ( fa, بهشهر; formerly Ashraf and Ashraf ol Belād) is a city in Mazandaran, Iran & the capital of Behshahr County. Located on the coast of the Caspian Sea, at the foot of the Alborz, it is approximately from Sari. At the 2006 cen ...

** Chalus **

Fenderesk Fenderesk ( fa, فندرسک) is a district (bakhsh) in Golestan Province in northern Iran. At the 2006 census, its population was 34,326, in 8,206 families. Khan Bebin ( fa, خان بهبین) is the district's only city. The district contains t ...

**

Gomishan Gomishan ( fa, گميشان, also Romanized as Gomīshān and Gumshān; formerly, Gomish Tepe ( fa, گميش‌تپه), also Romanized as Gomesh Tappeh, Gomīsh Tappeh, and Gumish Tepe; also formerly known as Gomish Tepe Jik ( fa, گُمیش‌ت ...

** Gonbad-e Kavus ** Gorgan **

Juybar Juybar ( fa, جويبار, also Romanized as Jūybār; also known as Bāghlū) is a city and capital of Juybar County, Mazandaran Province, Iran. In the 2006 census, its population was 27,117, with 7,052 families. This city is known as the wr ...

**

Kordkuy Kordkuy ( fa, كرد كوی; also Romanized as Kord Kūy, Kord Kū, and Kurd Kūi) is a city and capital of Kordkuy County, in Golestan Province, Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a ...

**

Lahijan Lahijan ( fa, لاهیجان, Lāhijān, also known as, Lāyjon in Gilaki) is a city near the Caspian Sea and the capital of Lahijan County, Gilan Province, Iran. According to the 2016 census, its population was 167,544 in 58,378 families. La ...

**

Langarud Langarud ( fa, لنگرود, also Romanized as Langarūd, Langerūd, Langaroud and Langarood; also known as Shahr-e Langarūd), is a city and capital of Langarud County, Gilan Province, Iran. The 2017 census showed the population as 79,445. La ...

** Mahmudabad **

Neka Neka ( fa, نكا, also Romanized as Nekā’ and Nekā; also known as Nīkā; formerly, Nāranj Bāgh) is a city and capital of Neka County, Mazandaran Province, Iran. At the 2006 census, its population was 46,152, in 11,941 families. Geograph ...

** Nowshahr ** Nur **

Ramsar Ramsar may refer to: * Places so named: ** Ramsar, Mazandaran, city in Iran ** Ramsar, Rajasthan, village in India * Eponyms of the Iranian city: ** Ramsar Convention concerning wetlands, signed in Ramsar, Iran ** Ramsar site, wetland listed in a ...

** Rasht ** Rudbar **

Rudsar Rudsar ( fa, رودسر, also known as, Roodsar, Rūdsar and Rūd-i-Sar) is a city and capital of Rudsar County, Gilan Province, Iran. At the 2006 census, its population was 33,321, in 9,741 families. Geography Rudsar is located on the Casp ...

**

Sari A sari (sometimes also saree or shari)The name of the garment in various regional languages include: * as, শাৰী, xārī, translit-std=ISO * bn, শাড়ি, śāṛi, translit-std=ISO * gu, સાડી, sāḍī, translit-std= ...

**

Sorkhrud Sorkhrud ( fa, سرخرود, also Romanized as Sorkhrūd, Sorkh Rūd, and Surkhrūd; also known as Sokhrun and Sorkhrūd-e Gharbī) is a city and capital of Sorkhrud District, in Mahmudabad County, Mazandaran Province, Iran Iran, ...

**

Tonekabon Tonekabon ( fa, تنكابن, also Romanized as Tonekābon; formerly known as Shahsavar (Persian: شَهسَوار), also Romanized as Shahsavār and Shahsawār) is a city and capital of Tonekabon County, Mazandaran Province, northern Iran. At t ...

*

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...

: ** Astara **

Baku Baku (, ; az, Bakı ) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. Baku is located below sea level, which makes it the lowest lying national capital in the world a ...

** Gobustan **

Khudat , native_name = , pushpin_map = Azerbaijan , pushpin_mapsize = 300 , subdivision_type = Country , subdivision_name = , subdivision_type1 = District , subdivision_name1 = Kh ...

** Khachmaz **

Lankaran Lankaran ( az, Lənkəran, ) is a city in Azerbaijan, on the coast of the Caspian Sea, near the southern border with Iran. As of 2021, the city had a population of 89,300. It is next to, but independent of, Lankaran District. The city forms a dis ...

**

Masallı Masallı () is a city in and the capital of the Masally District of Azerbaijan. History Masally city was established in 1960. The name of the city comes from the name of a tribe – “Masal” that lived in the territory of Masally in ancient ...

** Nabran ** Neftchala ** Shabran **

Siyazan Siyazan ( az, Siyəzən; Tat: ''Siyəzən'') is a city, municipality and the capital of the Siyazan District of Azerbaijan. It has a population of 24,900. The city's name is said to be derived from Persian Persian may refer to: * People and th ...

**

Oil Rocks An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...

** Sumqayit *

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

: **

Atyrau Atyrau ( kk, Атырау, ', ; russian: Атырау, ), known until 1991 as Guryev (russian: Гурьев, ), is a city in Kazakhstan and the capital of Atyrau Region. Atyrau is a transcontinental city, at the mouth of the Ural River on the Cas ...

** Aktau *Russia: ** Astrakhan **

Dagestanskiye Ogni Dagestanskiye Ogni (russian: Дагестанские Огни ; tab, Дагъустнан ЦIаяр; az, Дағыстан Ишыглары, ''Dağıstan İşıqları''; lez, Дагъустандин ЦӀаяр) is a town in the Republic of Da ...

**

Derbent Derbent (russian: Дербе́нт; lez, Кьвевар, Цал; az, Дәрбәнд, italic=no, Dərbənd; av, Дербенд; fa, دربند), formerly romanized as Derbend, is a city in Dagestan, Russia, located on the Caspian Sea. It is ...

**

Izberbash Izberbash (russian: Изберба́ш; Dargwa: Избир; kum, Йизбирба́ш, ''Yizbirbaş'') is a town in the Republic of Dagestan, Russia, located on the coast of the Caspian Sea southeast of Makhachkala, the capital of the republic. ...

** Kaspiysk ** Makhachkala *

Turkmenistan Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the sout ...

: ** Türkmenbaşy (formerly Krasnovodsk) ** Hazar (formerly Çeleken) **

Esenguly Esenguly (formerly Hasan-Kuly, Gasan-Kuli) is a city in and administrative center of Esenguly District, Balkan Province, Turkmenistan. In 1989 its population was 5,823. Etymology The name is of obscure origin. A clan of that name, part of the Yo ...

** Garabogaz (formerly Bekdaş)

Economy

Countries in the Caspian region, particularly

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...

,

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

and

Turkmenistan Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the sout ...

, have high-value natural-resource-based economies, where the oil and gas compose more than 10 percent of their GDP and 40 percent of their exports. All the Caspian region economies are highly dependent on this type of

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ( ...

wealth. The

world energy market World energy supply and consumption is global production and preparation of fuel, generation of electricity, energy transport, and energy consumption. It is a basic part of economic activity. It includes heat, but not energy from food. This a ...

s were influenced by Azerbaijan and Kazakhstan, as they became strategically crucial in this sphere, thus attracting the largest share of FDI (foreign direct investment). All of the countries are rich in solar energy and harnessing potential, with the highest rainfall much less than the mountains of central Europe in the mountains of the west, which are also rich in

hydroelectricity Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other Renewabl ...

sources.

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

has high fossil fuel energy potential. It has reserves of 137.5 billion

barrels A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, u ...

of

crude oil Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crude ...

, the fourth largest in the world, producing around four million barrels a day. Iran has an estimated 988.4 trillion cubic feet of

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...

, around 16 percent of world reserves, thus key to current paradigms in global energy security. Russia's economy ranks as the twelfth largest by nominal GDP and sixth largest by

purchasing power parity Purchasing power parity (PPP) is the measurement of prices in different countries that uses the prices of specific goods to compare the absolute purchasing power of the countries' currency, currencies. PPP is effectively the ratio of the price of ...

in 2015. Russia's extensive mineral and energy resources are the largest such reserves in the world, making it the second leading producer of oil and

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...

globally. Caspian

littoral The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal areas ...

states join efforts to develop infrastructure, tourism and trade in the region. The first

Caspian Economic Forum The Caspian Economic Forum (CEF; Turkmen: ''Hazar Ykdysady Forumy''; Russian: ''Каспийский экономический форум'') is an international economic event aiming to provide a platform for discussion of the issues relating to ...

was convened on August 12, 2019, in Turkmenistan and brought together representatives of Kazakhstan, Russia, Azerbaijan, Iran and that state. It hosted several meetings of their ministers of economy and transport. The Caspian countries develop robust cooperation in the tech and digital field as part of the Caspian Digital Hub. The project helps expand data transmission capabilities in Kazakhstan as well as data transit capabilities between Asia and Europe. The project generated interest from investors from all over the world, including the UK.

Oil and gas

The Caspian Sea region presently is a significant, but not major, supplier of

crude oil Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crude ...

to world markets, based upon estimates by BP Amoco and the U.S.

Energy Information Administration The U.S. Energy Information Administration (EIA) is a principal agency of the U.S. Federal Statistical System responsible for collecting, analyzing, and disseminating energy information to promote sound policymaking, efficient markets, and publ ...

,

U.S. Department of Energy The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and manages the research and development of nuclear power and nuclear weapons in the United States. ...

. The region output about 1.4–1.5 million

barrels A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, u ...

per day plus natural

gas Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...

liquids in 2001, 1.9% of total world output. More than a dozen countries output more than this top figure. Caspian region production has been higher, but waned during and after the collapse of the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

.

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

accounts for 55% and

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...

for about 20% of the states' oil output. Caspian region oil and natural gas infrastructure

The world's first offshore wells and machine-drilled wells were made in Bibi-Heybat Bay, near Baku, Azerbaijan. In 1873, exploration and development of oil began in some of the largest fields known to exist in the world at that time on the

Absheron Peninsula The Absheron Peninsula ( az, Abşeron yarımadası) is a peninsula in Azerbaijan. It is the location of Baku, the biggest and the most populous city of the country, and also the Baku metropolitan area, with its satellite cities Sumqayit and Khyrd ...

near the villages of Balakhanli, Sabunchi, Ramana, and Bibi Heybat. Total recoverable reserves were more than 500 million tons. By 1900, Baku had more than 3,000 oil wells, 2,000 of which were producing at industrial levels. By the end of the 19th century, Baku became known as the "black gold capital", and many skilled workers and specialists flocked to the city. By the beginning of the 20th century, Baku was the center of the international oil industry. In 1920, when the

Bolsheviks The Bolsheviks (russian: Большевики́, from большинство́ ''bol'shinstvó'', 'majority'),; derived from ''bol'shinstvó'' (большинство́), "majority", literally meaning "one of the majority". also known in English ...

captured

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...

, all private property, including oil wells and factories, was confiscated. Rapidly the republic's oil industry came under the control of the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

. By 1941, Azerbaijan was producing a record 23.5 million tons of oil per year – its Baku region output was nearly 72 percent of the Soviet Union's oil. In 1994, the " Contract of the Century" was signed, heralding extra-regional development of the Baku oil fields. The large Baku–Tbilisi–Ceyhan pipeline conveys Azeri oil to the Turkish Mediterranean port of Ceyhan and opened in 2006. The oil field in the Russian section of the body of water was discovered in 2005. It is reportedly the largest found in 25 years. It was announced in October 2016 that

Lukoil The PJSC Lukoil Oil Company ( stylized as LUKOIL or ЛУКОЙЛ in Cyrillic script) is a Russian multinational energy corporation headquartered in Moscow, specializing in the business of extraction, production, transport, and sale of petrol ...

would start production from it.

Transport

Baku Baku (, ; az, Bakı ) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. Baku is located below sea level, which makes it the lowest lying national capital in the world a ...

has the main moorings of all large vessels, such as oil tankers, in

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...

. It is the largest port of the Caspian Sea. The port (and tankers) have access to the oceans along the Caspian Sea–Volga–

Don Don, don or DON and variants may refer to: Places *County Donegal, Ireland, Chapman code DON *Don (river), a river in European Russia *Don River (disambiguation), several other rivers with the name *Don, Benin, a town in Benin *Don, Dang, a vill ...

Canal Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface flow un ...

, and the Don–

Sea of Azov The Sea of Azov ( Crimean Tatar: ''Azaq deñizi''; russian: Азовское море, Azovskoye more; uk, Азовське море, Azovs'ke more) is a sea in Eastern Europe connected to the Black Sea by the narrow (about ) Strait of Kerch, ...

. A northern alternate is the Volga–Baltic (a sea which has a connection to the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

of the Atlantic, as the

White Sea The White Sea (russian: Белое море, ''Béloye móre''; Karelian and fi, Vienanmeri, lit. Dvina Sea; yrk, Сэрако ямʼ, ''Serako yam'') is a southern inlet of the Barents Sea located on the northwest coast of Russia. It is su ...

does via the White Sea-Baltic canal. Baku Sea Trade Port and Caspian Shipping Company CJSC, have a big role in the sea transportation of Azerbaijan. The Caspian Sea Shipping Company CJSC has two fleets plus shipyards. Its transport fleet has 51 vessels: 20 tankers, 13 ferries, 15 universal dry cargo vessels, 2 Ro-Ro vessels, as well as 1 technical vessel and 1 floating workshop. Its specialized fleet has 210 vessels: 20 cranes, 25 towing and supplying vehicles, 26 passenger, two pipe-laying, six fire-fighting, seven engineering-geological, two diving and 88 auxiliary vessels. The Caspian Sea Shipping Company of Azerbaijan, which acts as a liaison in the Transport Corridor Europe-Caucasus-Asia (TRACECA), simultaneously with the transportation of cargo and passengers in the Trans-Caspian direction, also performs work to fully ensure the processes of oil and gas production at sea. In the 19th century, the sharp increase in oil production in

Baku Baku (, ; az, Bakı ) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. Baku is located below sea level, which makes it the lowest lying national capital in the world a ...

gave a huge impetus to the development of shipping in the Caspian Sea, and as a result, there was a need to create fundamentally new floating facilities for the transportation of oil and oil products.

Political issues

Many of the islands along the Azerbaijani coast retain great geopolitical and economic importance for demarcation-line oil fields relying on their national status. Bulla Island, Pirallahı Island, and Nargin, which is still used as a former

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

base and is the largest island in the

Baku Baku (, ; az, Bakı ) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. Baku is located below sea level, which makes it the lowest lying national capital in the world a ...

bay, hold oil reserves. The collapse of the Soviet Union allowed the market opening of the region. This led to intense investment and development by international oil companies. In 1998,

Dick Cheney Richard Bruce Cheney ( ; born January 30, 1941) is an American politician and businessman who served as the 46th vice president of the United States from 2001 to 2009 under President George W. Bush. He is currently the oldest living former U ...

commented that "I can't think of a time when we've had a region emerge as suddenly to become as strategically significant as the Caspian." A key problem to further local development is arriving at precise, agreed demarcation lines among the five

littoral The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal areas ...

states. The current disputes along Azerbaijan's maritime borders with Turkmenistan and Iran could impinge future development. Much controversy currently exists over the proposed Trans-Caspian oil and gas pipelines. These projects would allow Western markets easier access to Kazakh oil and, potentially, Uzbek and Turkmen gas as well. Russia officially opposes the project on environmental grounds.Sergei Blagov,
Russia Tries to Scuttle Proposed Trans-Caspian Pipeline
", Eurasianet (2006-03-27) However, analysts note that the pipelines would bypass Russia completely, thereby denying the country valuable transit fees, as well as destroying its current

monopoly A monopoly (from Greek language, Greek el, μόνος, mónos, single, alone, label=none and el, πωλεῖν, pōleîn, to sell, label=none), as described by Irving Fisher, is a market with the "absence of competition", creating a situati ...

on westward-bound

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ex ...

exports from the region. Recently, both Kazakhstan and Turkmenistan have expressed their support for the Trans-Caspian Pipeline. U.S. diplomatic cables disclosed by

WikiLeaks WikiLeaks () is an international Nonprofit organization, non-profit organisation that published news leaks and classified media provided by anonymous Source (journalism), sources. Julian Assange, an Australian Internet activism, Internet acti ...

revealed that BP covered up a gas leak and

blowout Blowout or Blow out may refer to: Film and television *''Blow Out'', a 1981 film by Brian De Palma * ''The Blow Out'', a 1936 short film * ''Blow Out'' (TV series), a TV series on Bravo * "Blow Out" (''Prison Break''), an episode of ''Prison ...

incident in September 2008 at an operating gas field in the Azeri-Chirag-Guneshi area of the Azerbaijan Caspian Sea.

Territorial status

Iran southern caspian energy prospects 2004

Coastline

Five states are located along about of Caspian coastline. The length of the coastline of these countries: # Kazakhstan - # Turkmenistan - # Azerbaijan - # Russia - # Iran -

Negotiations

In 2000, negotiations as to the

demarcation Demarcation is the act of creating a boundary around a place or thing. Demarcation may also refer to: *Demarcation line, a temporary border between the countries *Demarcation problem, the question of which practices of doing science permit the re ...

of the sea had been going on for nearly a decade among all the states bordering it. Whether it was by law a sea, a lake, or an agreed hybrid, the decision would set the demarcation rules and was heavily debated. Access to mineral resources ( oil and

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...

), access for fishing, and access to international waters (through Russia's

Volga The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the List of rivers of Europe#Rivers of Europe by length, longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Cas ...

river and the canals connecting it to the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

and

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

) all rest on the negotiations' outcome. Access to the Volga is key for market efficiency and economic diversity of the

landlocked A landlocked country is a country that does not have territory connected to an ocean or whose coastlines lie on endorheic basins. There are currently 44 landlocked countries and 4 landlocked de facto states. Kazakhstan is the world's largest ...

states of Azerbaijan, Kazakhstan, and Turkmenistan. This concerns Russia as more traffic seeks to use — and at some points congest — its inland

waterway A waterway is any navigable body of water. Broad distinctions are useful to avoid ambiguity, and disambiguation will be of varying importance depending on the nuance of the equivalent word in other languages. A first distinction is necessary b ...

s. If the body of water is, by law, a sea, many precedents and international treaties oblige free access to foreign vessels. If it is a lake there are no such obligations. Resolving and improving some

environmental A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...

issues properly rests on the status and

border Borders are usually defined as geographical boundaries, imposed either by features such as oceans and terrain, or by political entities such as governments, sovereign states, federated states, and other subnational entities. Political borders c ...

s issue. All five Caspian littoral states maintain naval forces on the sea. According to a treaty signed between Iran and the Soviet Union, the sea is technically a lake and was divided into two sectors (Iranian and Soviet), but the resources (then mainly fish) were commonly shared. The line between the two sectors was considered an international border in a common lake, like Lake Albert. The Soviet sector was sub-divided into the four littoral republics' administrative sectors. Russia, Kazakhstan, and Azerbaijan have bilateral agreements with each other based on

median In statistics and probability theory, the median is the value separating the higher half from the lower half of a data sample, a population, or a probability distribution. For a data set, it may be thought of as "the middle" value. The basic fe ...

lines. Because of their use by the three nations, median lines seem to be the most likely method of delineating territory in future agreements. However, Iran insists on a single, multilateral agreement between the five nations (aiming for a one-fifth share). Azerbaijan is at odds with Iran over some of the sea's

oil field A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the presence ...

s. Occasionally, Iranian patrol boats have fired at vessels sent by Azerbaijan for exploration into the disputed region. There are similar tensions between Azerbaijan and Turkmenistan (the latter claims that the former has pumped more oil than agreed from a field, recognized by both parties as shared). The Caspian littoral states' meeting in 2007 signed an accord that only allows littoral-state flag-bearing ships to enter the sea. Negotiations among the five states ebbed and flowed, from about 1990 to 2018. Progress was notable in the fourth Caspian Summit held in Astrakhan in 2014.

Caspian Summit

The Caspian Summit is a head of state-level meeting of the five littoral states. The fifth Caspian Summit took place on August 12, 2018, in the Kazakh port city of Aktau. The five leaders signed the ‘Convention on the Legal Status of the Caspian Sea’. Representatives of the Caspian littoral states held a meeting in the capital of Kazakhstan on September 28, 2018, as a follow-up to the Aktau Summit. The conference was hosted by the Kazakh Ministry of Investment and Development. The participants in the meeting agreed to host an investment forum for the Caspian region every two years.

Convention on the legal status of the Caspian Sea

The five littoral states build consensus on legally binding governance of the Caspian Sea through Special Working Groups of a Convention on the Legal Status of the Caspian Sea. In advance of a Caspian Summit, the 51st Special Working Group took place in Astana in May 2018 and found consensus on multiple agreements: Agreements on cooperation in the field of transport; trade and economic cooperation; prevention of incidents on the sea; combating terrorism; fighting against organized crime; and border security cooperation. The convention grants jurisdiction over of territorial waters to each neighboring country, plus an additional of exclusive fishing rights on the surface, while the rest is international waters. The seabed, on the other hand, remains undefined, subject to bilateral agreements between countries. Thus, the Caspian Sea is legally neither fully a sea nor a lake. While the convention addresses caviar production, oil and gas extraction, and military uses, it does not touch on environmental issues.

Crossborder inflow

UNECE recognizes several rivers that cross international borders which flow into the Caspian Sea. These are:

Transportation

Although the Caspian Sea is

endorheic An endorheic basin (; also spelled endoreic basin or endorreic basin) is a drainage basin that normally retains water and allows no outflow to other external bodies of water, such as rivers or oceans, but drainage converges instead into lakes ...

, its main tributary, the

Volga The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the List of rivers of Europe#Rivers of Europe by length, longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Cas ...

, is connected by important shipping canals with the Don River (and thus the Black Sea) and with the Baltic Sea, with branch canals to Northern Dvina and to the White Sea. Another Caspian tributary, the Kuma River, is connected by an irrigation canal with the Don basin as well. Scheduled

ferry A ferry is a ship, watercraft or amphibious vehicle used to carry passengers, and sometimes vehicles and cargo, across a body of water. A passenger ferry with many stops, such as in Venice, Italy, is sometimes called a water bus or water taxi ...

services (including

train ferries A train ferry is a ship (ferry) designed to carry railway vehicles. Typically, one level of the ship is fitted with railway tracks, and the vessel has a door at the front and/or rear to give access to the wharves. In the United States, train f ...

) across the sea chiefly are between: * Türkmenbaşy in

Turkmenistan Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the sout ...

, (formerly Krasnovodsk) and

Baku Baku (, ; az, Bakı ) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. Baku is located below sea level, which makes it the lowest lying national capital in the world a ...

. * Aktau, Kazakhstan and Baku. *Cities in Iran and Russia (chiefly for cargo.)

Canals

As an endorheic basin, the Caspian Sea basin has no natural connection with the ocean. Since the

medieval period In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...

, traders reached the Caspian via a number of

portage Portage or portaging (Canada: ; ) is the practice of carrying water craft or cargo over land, either around an obstacle in a river, or between two bodies of water. A path where items are regularly carried between bodies of water is also called a ...

s that connected the Volga and its tributaries with the Don River (which flows into the

Sea of Azov The Sea of Azov ( Crimean Tatar: ''Azaq deñizi''; russian: Азовское море, Azovskoye more; uk, Азовське море, Azovs'ke more) is a sea in Eastern Europe connected to the Black Sea by the narrow (about ) Strait of Kerch, ...

) and various rivers that flow into the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

. Primitive canals connecting the Volga Basin with the Baltic were constructed as early as the early 18th century. Since then, a number of canal projects have been completed. The two modern canal systems that connect the Volga Basin, and hence the Caspian Sea, with the ocean are the

Volga–Baltic Waterway The Volga–Baltic Waterway (Volgobalt, Волгобалт), formerly known as the Mariinsk Canal System (Russian: Мариинская водная система), is a series of canals and rivers in Russia which link the Volga with the Balti ...

and the

Volga–Don Canal Lenin Volga–Don Shipping Canal (Russian:Волго-Донской судоходный канал имени, ''В. И. Ленина, Volga-Donskoy soudokhodniy kanal imeni V. I. Lenina'', abbreviated ВДСК, ''VDSK'') is a ship canal in Rus ...

. The proposed Pechora–Kama Canal was a project that was widely discussed between the 1930s and 1980s. Shipping was a secondary consideration. Its main goal was to redirect some of the water of the

Pechora River ; Komi: Печӧра; Nenets: Санэроˮ яха , name_etymology = The Russian name of the river is a combination of two words in an old local Nenets dialect, "pe" & "chora". Literally it means "forest dweller". , image ...

(which flows into the Arctic Ocean) via the Kama River into the Volga. The goals were both irrigation and the stabilization of the water level in the Caspian, which was thought to be falling dangerously fast at the time. During 1971, some peaceful nuclear construction experiments were carried out in the region by the U.S.S.R. In June 2007, in order to boost his oil-rich country's access to markets,

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

's President Nursultan Nazarbayev proposed a link between the Caspian Sea and the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

. It is hoped that the " Eurasia Canal" ( Manych Ship Canal) would transform landlocked Kazakhstan and other

Central Asian countries Central Asia, also known as Middle Asia, is a region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes the former S ...

into maritime states, enabling them to significantly increase trade volume. Although the canal would traverse Russian territory, it would benefit Kazakhstan through its Caspian Sea ports. The most likely route for the canal, the officials at the Committee on Water Resources at Kazakhstan's Agriculture Ministry say, would follow the Kuma–Manych Depression, where currently a chain of rivers and lakes is already connected by an irrigation canal (the Kuma–Manych Canal). Upgrading the Volga–Don Canal would be another option."Caspian Canal Could Boost Kazakh Trade"
''

Business Week ''Bloomberg Businessweek'', previously known as ''BusinessWeek'', is an American weekly business magazine published fifty times a year. Since 2009, the magazine is owned by New York City-based Bloomberg L.P. The magazine debuted in New York City ...

'' (2007-07-09)

References

External links

*
Names of the Caspian Sea

Caspian Sea Region

{{Authority control Ancient lakes Azerbaijan–Iran border Azerbaijan–Russia border Bodies of water of Iran Border tripoints Endorheic lakes of Europe Endorheic lakes of Asia Eutrophication Geography of Central Asia Geography of Eastern Europe Geography of Southern Russia Geography of Western Asia International disputes International lakes of Asia International lakes of Europe Iran–Soviet Union border Iran–Turkmenistan border Kazakhstan–Russia border Kazakhstan–Turkmenistan border Lakes of Astrakhan Oblast Lakes of Azerbaijan Lakes of Dagestan Lakes of Iran Lakes of Kalmykia Lakes of Kazakhstan Lakes of Turkmenistan Landforms of Central Asia Landforms of Western Asia Lowest points Saline lakes of Asia Saline lakes of Europe Seas of Iran

Etymology

Basin countries

Border countries

Non-border countries

Physical characteristics

Formation

Geography

Climate

Hydrology

Environmental degradation

Flora and fauna

Flora

Fauna

History

Geology

Early settlement nearby

Chinese maximal limit

Fossil fuel

Geography, geology and navigation studies

Cities

Ancient

Modern

Economy

Oil and gas

Transport

Political issues

Territorial status

Coastline

Negotiations

Caspian Summit

Convention on the legal status of the Caspian Sea

Crossborder inflow

Transportation

Canals

See also

References

External links