The palaeolimnology of the Aral Sea: A review

Formerly the fourth largest inland water body in the world, the volume and area of the Aral Sea have decreased dramatically over the past 30 yr largely as a result of human actions. Throughout its approximately 2 million year history the fate of this water body has been intimately linked with that of its two main in-flowing rivers, the Amu Darya and the Syr Darya. We present a review of the hydrological, palaeontological and sedimentological evidence for the evolution of the Aral Sea based largely on Russian literature. Although the structure of the Aral Basin can be traced back to the late Neogene, the Sea has only existed in its present form for the past 8-10 ka and the Holocene history has been shaped by regional climatic variations, the development of the associated drainage system and anthropogenic forces. Past hydrological changes in the Aral Basin have led to systematic shifts in the level of the Aral Sea which are reflected sedimentologically through the deposition of 'transgressive' and 'regressive' sedimentary units and geomorphologically through the development of terraces. All the above data are integrated to produced a Late Quaternary history of this important water body. (C) 2000 Elsevier Science Ltd.