Caspian Sea of around 149,200 square miles (386,400 square km)— bigger than the region of Japan—and its surface lies somewhere in the range of 90 feet (27 meters) below sea level. The sea bed in the southern part reaches as low as 1,023 m (3,356 ft) below sea level, which is the second lowest natural depression on earth after Lake Baikal (−1,180 m, −3,871 ft). The ancient inhabitants of its coast perceived the Caspian Sea as an ocean, probably because of its saltiness and large size. The sea has a surface area of 371,000 km (143,200 sq mi) (not including the detached
Eustatic sea level molecular motion, thus water molecules will occupy a lesser space. • Thermal expansion may also be influenced by ocean salinity. As continental ice accumulates, the ocean water freezes onto land but the salt it carried will mostly remain in the ocean. Thus, as ice sheets increase, ocean salinity also increases (and vice-versa). An increase in salinity will increase the density of the ocean basin. Melting of ice sheets and a decrease of ocean salinity will effectively decrease the density of the water. Eustatic sea level The eustatic sea level is the distance from the center of the earth to the