Lake Chad

Lake Chad, central Africa, at the junction of Chad, Cameroon, Nigeria, and Niger, about 250 m (820 ft) above sea level. Lake Chad is fed principally by the Shari (Chari) and Logone rivers. Although the lake has no visible outlet, it is steadily decreasing in size because of evaporation and underground seepage. In the rainy season the area of the lake is as great as 25,900 sq km (10,000 sq mi), but in the dry season it shrinks to as little as 10,360 sq km (4,000 sq mi) and recent climatic change has reduced this minimum level still further. In open water the depth of the lake varies from about 1 m (3 ft) in the north-west to more than 6 m (20 ft) in the south. The numerous islands lying along the eastern shore of the lake are inhabited, and crocodile and hippopotamus are abundant. The present lake is the remains of a much larger inland sea, which during the Pleistocene epoch (the last ice age, some 15,000-25,000 years ago) covered about 300,000 sq km (116,000 sq mi).