The Caspian Depression ( kk, Каспий маңы ойпаты, ''Kaspıı mańy oıpaty''; rus, Прикаспи́йская ни́зменность, p=prʲɪkɐˈspʲijskəjə ˈnʲizmʲɪnnəsʲtʲ, Caspian Lowland) or Pricaspian/Peri-Caspian Depression/Lowland is a low-lying

flatland ''Flatland: A Romance of Many Dimensions'' is a satirical novella by the English schoolmaster Edwin Abbott Abbott, first published in 1884 by Seeley & Co. of London. Written pseudonymously by "A Square", the book used the fictional two-dim ...

region encompassing the northern part of the

Caspian Sea The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...

, the largest enclosed

body of water A body of water or waterbody (often spelled water body) is any significant accumulation of water on the surface of Earth or another planet. The term most often refers to oceans, seas, and lakes, but it includes smaller pools of water such as p ...

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

. It is the larger northern part of the wider Aral-Caspian Depression around the Aral and Caspian Seas. The level of the Caspian sea is below sea level, however several areas in the depression are even lower, and among them

Karagiye Karagiye ( kk, Қарақия ойысы, ''Qaraqiia oiysy''; Karagiye means ''Black Jaw'' in Turkic) is a long karst trench close to the Caspian Sea. At its lowest point at Vpadina Kaundy, it is approximately below sea level. It is the lowes ...

near

Aktau Aktau ( kk, Aqtau, Ақтау , russian: Актау) is a city in Kazakhstan, located on the eastern shore of the Caspian Sea. Its current name means "white mountain" in Kazakh, which may be due to its cliffs that overlook the Caspian. From 1964 to ...

is the lowest at .

Geography

The depression lies at the southern end of the

Ryn Desert The Ryn Desert or Ryn-Peski Desert ( kk, Нарын құмы, ''Naryn-Qūmy''; russian: Рын-пески) is a desert in western Kazakhstan and Astrakhan Oblast, Russia. High winds sweep across the desert, and in 2001 a dust storm in the Balti ...

, and is in both

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

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 ...

. Most of the Russian Republic of

Kalmykia he official languages of the Republic of Kalmykia are the Kalmyk and Russian languages./ref> , official_lang_list= Kalmyk , official_lang_ref=Steppe Code (Constitution) of the Republic of Kalmykia, Article 17: he official languages of the ...

lies in the Caspian Depression. 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 ...

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 ...

flow into the Caspian Sea through this region. The deltas of the Ural and Volga Rivers are extensive wetlands. The North Caspian depression is part of the

continental Continental may refer to: Places * Continent, the major landmasses of Earth * Continental, Arizona, a small community in Pima County, Arizona, US * Continental, Ohio, a small town in Putnam County, US Arts and entertainment * ''Continental'' ( ...

semi-arid 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 ...

desert

biome 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 ...

. The area receives of rain per year, on average, and less than 10% of the region is irrigated. The main rivers of the lowland beside the Volga and the Ural are the Emba, Terek and Kuma. There are also numerous salt lakes, such as

Baskunchak Lake Baskunchak (russian: Баскунчак; kk, Басқұншақ, translit=Basqunshaq) is a salt lake of 115 km² in Astrakhan Oblast, Russia, located at , about 270 km north of the Caspian Sea, and 53 km east of the Volga. Si ...

Inder Inder may refer to: ;People * Inder Bawra, an Indian music director ;Places * Inder, the administrative center of Jalaid Banner, Mongolia * Inder, a locality in the Nagpur district in state of Maharashtra, India * Inder District, a district of A ...

Aralsor Aralsor ( kk, Аралсор; russian: Аралсор) is a Bittern (salt), bittern salt lake in Bokey Orda District, West Kazakhstan Region, Kazakhstan. The lake lies about to the east of the Russian border, north of the R-97 Highway (Kazakhs ...

, Kamys-Samara,

Elton Elton may refer to: Places England * Elton, Cambridgeshire (formerly Huntingdonshire), a village ** Elton Hall, a baronial hall * Elton, Cheshire, a village and civil parish * Elton, County Durham, a village and civil parish * Elton, Derbyshire ...

and

Botkul Botkul ( kk, Боткөл; russian: Боткуль) is a bittern salt lake in the Kazakhstan–Russia border. There is no salt mining at the lake. Its waters have a bitter, stinging taste and a strong smell of hydrogen sulfide. The authorities ...

Google Earth Google Earth is a computer program that renders a 3D computer graphics, 3D representation of Earth based primarily on satellite imagery. The program maps the Earth by superimposition, superimposing satellite images, aerial photography, and geog ...

Caspian Lowland Population
/ref> The Caspian Depression is below sea level, consisting of large areas of

marshland A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...

s in the eastern region. It is one of the largest flat lowland areas in

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 ...

, covering approximately . The area is very rich in underground oil and gas reserves, and oil and natural gas pipelines cross the depression from north to south and east to west. Many

geologists A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althoug ...

believe the Caspian Sea and the depression were formed 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 ...

forces. Some of them also believe that the North Caspian depression became separated from the open ocean in ancient times to form an enormous salt lake. Part of the ancient

Silk Road The Silk Road () was a network of Eurasian trade routes active from the second century BCE until the mid-15th century. Spanning over 6,400 kilometers (4,000 miles), it played a central role in facilitating economic, cultural, political, and reli ...

ran through this region. The two largest cities in the depression are

Astrakhan Astrakhan ( rus, Астрахань, p=ˈastrəxənʲ) is the largest city and administrative centre of Astrakhan Oblast in Southern Russia. The city lies on two banks of the Volga, in the upper part of the Volga Delta, on eleven islands of the ...

in Russia and

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 ...

in Kazakhstan. Today, the region is used mainly for livestock raising. The depression is also noted for

salt dome A salt dome is a type of structural dome formed when salt (or other evaporite minerals) intrudes into overlying rocks in a process known as diapirism. Salt domes can have unique surface and subsurface structures, and they can be discovered using ...

s, particularly Volgograd salt. It increases dramatically as one travels from the

toward the Caspian Sea. Russian satellite photos have revealed huge deposits of salt domes (about 1,200), in the Caspian Depression in western Kazakhstan. One dome, called the Chelkar Deposit, covers an area of and is nearly deep. The southern region of the depression, or the north coast of the Caspian Sea, is characterized by the large development of damp sites resulting from

tidal Tidal is the adjectival form of tide. Tidal may also refer to: * ''Tidal'' (album), a 1996 album by Fiona Apple * Tidal (king), a king involved in the Battle of the Vale of Siddim * TidalCycles, a live coding environment for music * Tidal (servic ...

phenomena. The depression is also home to many

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, with several thousand different species likely living in the region around the Caspian Sea. Studies have shown that

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 ...

, mostly coming from the Volga River, poses a serious threat to the

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 ...

of the Caspian Depression. Water pollution is contributed mainly by

industrial Industrial may refer to: Industry * Industrial archaeology, the study of the history of the industry * Industrial engineering, engineering dealing with the optimization of complex industrial processes or systems * Industrial city, a city dominate ...

agricultural Agriculture or farming is the practice of cultivating Plant, plants and livestock. Agriculture was the key development in the rise of Sedentism, sedentary human civilization, whereby farming of Domestication, domesticated species created food ...

, and household discharges.

References

* Evaporites of North Border of North Caspian Depression – ''Internet Geology News Letter No. 178'', January 13, 2003. *
Space Today Online
{{Authority control Depressions of Russia Depressions of Kazakhstan Caspian Sea basin Lowest points East European Plain Depressions of Europe

Geography

See also

References