Description:
The Caspian Sea has been endoreic – inwardly draining – since the Pliocene era (about 5 million years ago), prompting some specialists to treat it as the world’s largest lake. Studies of its geomorphology and hydrology have revealed alternating cycles of rising and falling water levels, raising many questions, scientific for some, more down-to-earth for those living on its shores. In a century, between 1880 and 1977, the level of the sea dropped four metres (from -25 metres to -29 metres below mean sea level) apart from short periods during which it rose slightly. During this time local people became accustomed to the gradual drop in the water level, carrying out all sorts of work on the shores, particularly after the Second World War: port infrastructures, roads and railways, construction of housing and holiday facilities. In the Soviet Union the dramatic drying up of the Azov Sea, a side-basin of the Black Sea, which occurred at the same time, gave rise to genuine fears that the Caspian – or at least its very shallow northern part, which is less than 25 metres deep – would in turn shrink significantly. This led to hasty, misguided decisions such as the construction of a dyke in 1983 to close the Kara Bogaz Gol gulf.