Caspian Sea (ancient
Caspium Mare or Hyrcanium Mare), saltwater lake in southeastern
Europe and southwestern Asia, the largest inland body of water in the world. The
Caspian Sea is bordered on the west by Azerbaijan and Russia, on the northeast
and east by Kazakhstan, on the east by Turkmenistan, and on the south by Iran.
It extends about 1210 km (about 750 mi) in a northern and southern direction and
about 210 to 436 km (about 130 to 271 mi) in an eastern and western direction.
It has an area of 371,000 sq km (143,000 sq mi). The Caspian coastline is
irregular, with large gulfs on the east, including Krasnovodsk Gulf and the very
shallow Garabogazköl Gulf, which acts as an evaporation basin and is the site of
a major chemical plant that extracts salts from the deposits.
The Caspian Sea has a mean depth of about 170 m (about 550
ft) and is deepest in the south. Its level varies from year to year but averages
about 28 m (92 ft) below sea level. In the 1960s and 1970s the level fell
substantially, partly because water was withdrawn from tributary rivers for
irrigation and other purposes. In 1980 a dike was built across the mouth of
Garabogazköl Gulf in northwestern Turkmenistan to reduce water loss, creating a
lake that was expected to last for several years. Instead, the gulf dried up
completely by 1983. In the meantime, the level of the Caspian Sea began rising
again at a rate of about 14 to 20 cm (about 6 to 8 in) annually.
The southern and southwestern shorelines of the Caspian
Sea are bordered by the Elburz Mountains and the Caucasus Mountains. The sea has
numerous tributaries, notably the Volga, Ural, and Zhem rivers, all of which
flow into it from the north. Other tributaries include the Gorgan (Gurgan) and
Atrek rivers, flowing from the east, and the Kura River, flowing from the west.
The Caspian Sea has no outlet. However, it is linked to the Baltic Sea, the
White Sea, and the Black Sea by an extensive network of inland waterways, chief
of which is the Volga River.
Navigation is frequently dangerous because of violent
southeastern storms. During the winter months the northern parts of the Caspian
Sea are closed by ice. The chief ports are Krasnovodsk, Turkmenistan; Baku,
Azerbaijan; and Makhachkala, Russia.
The Caspian Sea region contains significant reserves of
oil and natural gas. The region is estimated to hold the third largest reserves
after the Middle East and Russia. Bordering countries are actively exploring and
tapping offshore reserves. However, national rights to offshore oil and gas
fields have been a point of dispute. In May 2003 Russia, Azerbaijan, and
Kazakhstan signed an agreement establishing boundaries in the Caspian Sea,
dividing the northern 64 percent of the seabed into national sectors and
allowing the surface to be used in common. Iran and Turkmenistan refused to sign
the agreement and continue to dispute offshore boundaries. Azerbaijan and
Kazakhstan are the region’s leading oil exporters. Baku, the capital of
Azerbaijan, is the chief point of export for oil obtained from offshore fields.
A new oil pipeline linking Baku with the Mediterranean seaport of Ceyhan,
Turkey, opened in 2005, supplementing two other pipelines linking Baku to ports
on the Black Sea.
Decades of environmental mismanagement have led to severe
pollution problems in the Caspian region. Discharges from offshore oil and gas
drilling and inflows from the highly polluted Volga River have contributed to
the degradation of Caspian waters. The pollution poses a serious threat to
animal life, including tortoises, porpoises, and seals. In addition, overfishing
has depleted the sea’s stocks of sturgeon (a source of caviar), salmon, perch,
herring, and carp. In November 2003 representatives from all the bordering
countries signed the United Nations-sponsored Convention for the Protection of
the Marine Environment of the Caspian Sea, which provided a framework for
alleviating environmental damage in the region. However, environmental laws and
regulations remain weak. See also Fisheries.
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