With around 400,000 km², the Caspian Sea is the largest lake on earth without drainage. Russia, Azerbaijan, Kazakhstan, Turkmenistan and Iran lie on the Caspian Sea. In north-south direction it extends over a length of about 1200 km, its mean width is about 320 km.
The main tributary is the Volga. The Caspian Sea repeatedly filled the entire Caspian Depression. The water level has sunk considerably since 1971 due to evaporation and water abstraction. The area of the Caspian Sea shrank. The water level has been rising significantly again since the late 1980’s. Today it is around 28 m below sea level. The salinity is high. Salt is extracted in the south of the Caspian Sea.
Extensive inland waterways open up the Caspian Sea from the north and south. All neighboring countries have large ports. The sturgeon stock is used for caviar extraction and is a wealth of the Caspian Sea. The region is rich in oil and natural gas. The affiliation of the oil deposits is controversial among the neighboring countries. The agreement signed between Russia and Iran in 1998, in which the deposits are divided between them, is rejected because of the all-encompassing claims of these two states and the disadvantage of the rest of them.
The Caspian Sea is the largest lake on earth with no outflow. Today it has an area of around 400,000 km² and is roughly the size of Japan. It extends over about 1200 km in north-south direction with a mean width of 320 km.
The countries of Azerbaijan, Russia, Kazakhstan, Turkmenistan and Iran border the Caspian Sea.
The largest tributary is the Volga. Their share in the water supply was once over 60%. It flows into the Caspian Sea in the northern part of Russia. Other important tributaries are the Kura, which flows into the western Azerbaijani part, and the Gorgan and Atrek, which flow into the Turkmen and Iranian parts in the south. There is no drain.
The Caspian Sea repeatedly filled the Caspian Depression, the roughly 200,000 km² desert lowland on the north shore. As a result of evaporation of 2,000 mm per year and the extraction of water to irrigate fields, the area of the Caspian Sea shrank from 1971 to less than 365,000 km².
Due to geological-tectonic processes, a gradual rise in the water level has been noticeable since 1977 and since the end of the 1980’s. Between 1977 and 1995 it was around 3 m. Today the water level of the Caspian Sea is around 28 m below sea level. At its deepest point in the southern part, the Caspian Sea is 1025 m deep.
Treasures of the Caspian Sea – fish and salt
The salinity of the water at the mouth of the Volga is 1%, in the central area around 14% and rises to 300% in the south on the east bank in the bay of Kara-Bogas-Gol. It belongs to Turkmenistan and is used for salt production.
The Caspian Sea is connected to the Baltic Sea, the White Sea and the Black Sea by an extensive network of inland waterways. Frequent south-east storms impede shipping. The northern parts of the Caspian Sea are also covered by ice in the winter months. The largest ports are Krasnovodsk in Turkmenistan, Baku in Azerbaijan, Makhachkala in Russia and Bender e Ansali in Iran.
The treasures of the Caspian Sea are the fish stocks. The fishing has declined by environmental pollution. The sturgeon catch for the production of caviar is of great importance. Herring, roach and carp are also caught.
Extraction of raw materials – natural gas and oil
The Caspian Sea and the surrounding Caspian Basin or Caspi region are rich in oil and natural gas. Industrial oil production began in Baku in Azerbaijan in 1872. The affiliation of the oil deposits is controversial. The five neighboring countries of Azerbaijan, Russia, Kazakhstan, Turkmenistan and Iran are arguing over the division of the oil stocks. The definition of the Caspian Sea plays a decisive role in this.
If it is defined as the sea, all riparian states have equal rights to mineral resources regardless of the length of their shore zone. If the Caspian Sea is defined as a lake, the area is divided into sectors based on the length of the shore. Azerbaijan and Kazakhstan have the greatest interest in the definition of the sea, as the sectors that would fall to them have the largest oil fields. Turkmenistan would also have a share in rich deposits, but it has joined Iran and Russia, which in a 1998 treaty divided up the oil reserves according to the definition of the sea. This is not recognized by the other neighboring countries.