inlet of the eastern Caspian Sea in northwestern Turkmenistan. With an area of 4,600–5,000 square miles (12,000–13,000 square km), it averages only 33 feet (10 m) in depth and has a very high evaporation rate. The water is thus extremely saline, and 7,000–11,000 cubic feet (200–300 cubic m) of water a second are drawn in from the Caspian through the narrow strait between the two sandy spits separating the gulf from the sea. The gulf has the world's largest deposit of natural marine salts (salt).