Caspian Sea
نویسنده: احسان(پنج شنبه 87/1/29 ساعت 8:14 صبح)
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 In the 1960s and 1970s the level fell substantially, partly because water was withdrawn from tributary rivers for irrigation and other purposes.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 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. To restore water flow into Garabogazköl Gulf an aqueduct was built.
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 sea has no outlet. The Caspian Sea 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. These waterways provide an outlet to northern Europe for the oil fields of Baku, Azerbaijan on the Ab5eron Peninsula. The Caspian Sea also contains highly productive fisheries, yielding valuable catches of sturgeon (the chief source of caviar), salmon, perch, herring, and carp. Other animal life in the Caspian Sea includes tortoises, porpoises, and seals.
Navigation is frequently dangerous because of violent southeastern storms, and during the winter months the northern parts of the Caspian Sea are closed by ice. The chief ports are Krasnovodsk, Turkmenistan; Baku; and Makhachkala, Russia.
لیست کل یادداشت های این وبلاگ
