Caspian Sea

　　The Caspian Sea is the world’s largest saltwater lake, situated in the heart of the Eurasian continent, between Asia and Europe. Its surface lies approximately 27 metres below sea level, and near the southern part, its maximum depth reaches 1,025 metres. The Caspian Sea has around 50 islands, most of which are small, with Chechen Island in the northwest being the largest. Other notable islands include Tyuleny Island, Morskoy Island, Kulaly Island, Zhiloy Island, and Ogurchin Island. Based on hydrological characteristics, the entire Caspian Sea is usually divided into three parts: northern, middle, and southern.

　　The Caspian Sea has a total of 130 inflowing rivers, with an annual runoff volume exceeding 300 cubic kilometres; among these, the Volga River contributes 256 cubic kilometres, accounting for 85% of the total inflow. The inflow exhibits significant seasonal and interannual variations, directly influencing changes in salinity and water levels. The seawater contains relatively low levels of chloride but higher levels of sulfate and carbonate. The salinity of the Caspian Sea is about two-thirds lower than the standard salinity of ocean water. The Caspian Sea boasts vast waters, stretching endlessly with often fierce winds and high waves, resembling the rolling swells of the ocean.