CASPIAN SEA

Russian Kaspiyskoye More, Persian Daryaye Khezer, world's largest inland sea, lying east of the Caucasus Mountains at Europe's southeasternmost extremity and dominating the huge, flat expanses of western Central Asia. The elongated basin of the Caspian Sea sprawls for nearly 750 miles (1,200 km) from north to south, although its average width is only 200 miles (320 km). Its area is approximately 149,200 square miles (386,400 square km). About 20 percent of the sea's shoreline, in the south, borders Iran at the foot of the Elburz Mountains; the remainder of the shoreline, once controlled by the former Soviet Union, is divided among Azerbaijan, Russia, Kazakstan, and Turkmenistan. The three major rivers flowing into the Caspian are the Volga, Ural, and Terek, all of which enter the sea from the north; their combined annual flow accounts for approximately 88 percent of all river water entering the sea. The Caspian possesses as many as 50 islands, most of them quite small. Its basin is generally divided into the north, middle, and south Caspian, based largely on seabed relief. The flat, sedimentary plain of the north Caspian is the shallowest portion of the sea, with an average depth of 13 to 20 feet (4 to 6 m). The middle Caspian forms an irregular depression with an abrupt western slope and a gentler eastern gradient. A depression reaching a maximum depth of 3,363 feet (1,025 m) dominates the south Caspian. The northern Caspian Sea lies in a moderately continental climatic zone, while all of the middle and most of the south Caspian lies in the moderately hot belt. Evaporation from the sea surface is very high, reaching as much as 40 inches (1,000 mm) per year. Long-term fluctuations in the area and depth of the Caspian have been recorded over the centuries, the lower levels being the result of climatic change affecting river inflow and causing increased evaporation. These conditions were compounded in the 20th century by reservoir construction on the Volga River and by river-water consumption and diversion for irrigation and industry. The Caspian's level fell consistently from the late 1920s to the late '70s, after which it rose rapidly, possibly owing to changing weather patterns that increased precipitation in the region. The rising sea flooded many areas that had been populated during the years of its decline. Oil derricks in the Caspian Sea near Baku, Azerbaijan. The Caspian long has been famous for its large catch of sturgeon, but overfishing, worsening pollution, and the damming of feeder rivers have substantially reduced their numbers. Oil and natural gas have become the region's most important resources since World War II. The Caspian is also of great importance in the transportation networks of the region. Its chief ports are Baku, Azerbaijan; Makhachkala and Astrakhan, Russia; Aqtau (formerly Shevchenko), Kazakstan; Trkmenbashy (formerly Krasnovodsk), Turkmenistan; and Bandar-e Anzali, Iran. The Caspian Sea and Karakum Desert. Russian Kaspiyskoye More, Persian Daryaye Khezer, world's largest inland sea, lying to the east of the Caucasus Mountains and dominating the huge, flat expanses of western Central Asia. Its name derives from the ancient Kaspi peoples, who once lived in Transcaucasia to the west; among its other historical names, Khazarsk and Khvalynsk derive from former peoples of the region, while Girkansk stems from Girkanos, Country of the Wolves. The elongated sea sprawls for nearly 750 miles (1,200 kilometres) from north to south, although its average width is only 200 miles. It covers an area of about 149,200 square miles (386,400 square kilometres)larger than Japanwhile its surface lies some 90 feet (27 metres) below sea level. The maximum depth, toward the south, is 3,360 feet (1,025 metres). The sea is bordered in the northeast by Kazakstan, in the southeast by Turkmenistan, in the south by Iran, in the southwest by Azerbaijan, and in the northwest by Russia. It is often stated that the Caspian is the greatest salt lake in the world. But this has not always been true, as scientific studies have shown that, until geologically quite recent times, it was linked, via the Sea of Azov, the Black Sea, and the Mediterranean, to the world ocean. This factor has molded strongly all aspects of its physical geography. The Caspian is of exceptional scientific interest, because its history, particularly in respect to former fluctuations in both area and depth, offers clues to the complex geologic and climatic evolution of the region. Man-made changes, notably those resulting from the construction of dams, reservoirs, and canals on the immense Volga River system (which drains into the Caspian from the north), have had their own effect on the contemporary hydrologic balance. The Caspian is also of great importance in the transportation networks of the region and in the production of petroleum and natural gas; and its splendid sandy beaches are used increasingly for health and recreation resorts. Additional reading Works on the Caspian Sea include A.N. Kosarev, Gidrologiia Kaspiiskogo i Aral'skogo morei (1975), a study of the hydrology of the Caspian and Aral seas; S.S. Baidin and A.N. Kosarev (eds.), Kaspiiskoe more: gidrologiia i gidrokhimiia (1987), an analysis of hydrology and chemistry of the Caspian Sea; and N.A. Krylov (ed.), Kaspiiskoe more: geologiia i neftegazonosnost' (1986), a survey of submarine geology, focusing on the Caspian gas and oil resources. Only brief treatments are available in English translation, including V.A. Vronskiy, The Holocene Stratigraphy and Paleogeography of the Caspian Sea, International Geology Review, 29(1):14-24 (1987); and Yu.A. Karpychev, Fluctuations of the Caspian Sea Level as an Indicator of Global Climatic Changes, Nuclear Geophysics, 4(1):5770 (1990). Aleksey Nilovich Kosarev