Caspian Sea

THE CASPIAN SEA IS ONE of the world’s largest bodies of water, situated in a depression between RUSSIA, KAZAKHSTAN, TURKMENISTAN, IRAN, and AZERBAIJAN. It is unique among the world’s inland seas in that it is completely isolated from the rest of the global ocean and has a distinctive continental climate which gives the area extremes in temperature, from very hot summers to very cold winters.

Several rivers flow into the Caspian Sea, most notably the VOLGA and the Ural in the far north and the Terek, Sulak and Kura rivers from Daghestan and the Caucasus to the west. In fact, by including the entire Volga River Basin, the Caspian has the largest catchment area in Europe (1.4 million square mi or 3.5 million square km). But no rivers flow out of the Caspian, and most of the water is lost through evaporation. This is aided by the fact that much of the Caspian is very shallow, particularly in the north and the east. These parts are also very low-lying: The lowest point in Europe is the surface of the Caspian Sea, 89 ft (27 m) below sea level. Most of the eastern coast of the Caspian Sea is dry, with the extreme southeastern corner leading directly onto the Kara Kum Desert. In contrast, the southern and western shores are more steep, culminating in the nearly vertical walls along the southern coast where the ELBURZ and Talysh mountains of Iran come down to the sea. The seafloor drops most dramatically in this region as well, with the Caspian’s greatest depths over 3,300 ft (1,000 m). The southwestern areas are also mountainous, consisting of the easternmost reaches of the CAUCASUS mountain ranges.

The Caspian stretches for over 620 mi (1,000 km) from north to south, and between 125 and 250 mi (200 and 400 km) east to west, totaling 143,270 square mi (393,000 square km) in area. It holds much of the world’s lacustrine (lake-associated) water: 18,881 cubic mi (78,700 cubic km) of mixed salty and brackish fresh water. The salinity of the Caspian is heavily dependent on the level of flow from the Volga.