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THE ARAL SEA AND SOUTH PREARALIE (1) Despite the fact that since the beginning of the past millennium many scientific volumes were devoted to the Aral Sea, its chronology remains contradictory and unclear. Since the second half of the nineteenth century the Aral Sea has become an object of numerous field studies conducted by the Russian Geographical Society and different scientific organizations of Russia. In 1908, the results of these studies were summarized by L. Berg in his great work “The Aral Sea Chronology Studies”, where he stated that none of Greek or Roman authors had directly or indirectly mentioned the Aral Sea, however, most of them had told about Oksa (Amu Darya) and Aksart (Syr Darya), at the same time, it remains unclear which water bodies they emptied into. According to the famous scientist Al Beruni from Khorezm, who died in 1048, the inhabitants of Khorezm, keeping their chronology since 1292 B.C., attested the existence of the Aral Sea. L. Berg has referred to the Holy Book of Avesta, in which it was mentioned that the Vakhsh or the present Amu Darya River flowed into Lake Varakhsha, which some people had in mind as the Aral Sea. The first more or less reliable sources regarding the existence of the Aral Sea pertain to Arabic scripts, which recorded evidences of the conquerors of Khorezm in 712 A.D. These reports that were well described by V.V. Bartold confirm that the Aral Sea has already existed in the eighth century and was located not far from Khorezm, as its description fully coincides with features of the eastern coast of the Aral Sea. Other evidences belong to Massudi ibn Nurusti, Al Balkhi and many other Arabic writers and investigators-geographers. Geological surveys carried out at the end of the nineteenth century and the beginning of the twentieth century (À.Ì. Konshin, P.M. Lessor, and V. Obruchev), have proved that in the post-Pliocene epoch the part of the Karakum Desert between cliffs of the Usturt Plateau in the north and the mouths of the Murgab and Tedjen rivers in the south, and the Kopetdag Mountain foot in the west had been flooded by the Big Aral Sea. The eastern half of the united Caspian-Aral Sea had, in their opinion, a cliff of the Unguz shoreline as the border of the former Karakum Bay. This united sea had covered a wide strip of the present pre-Caspian area right up to a foot of the western Kopetdag ridges, and linked with Karakum and Chilmetkum bays by two straits - the Bolshoy Balkhskiy and Maliy Balkhskiy. At that time the Aral part of the united sea flooded entirely the Sarykamysh depression and formed the bay stretched out to the Pitnyak, which is now occupied by the present-day delta of the Amu Darya and the Khiva oasis (as well, this explains the presence of salts deposit at the Pitnyak). The Uzboy Strait had linked both water areas, but it is obvious that its form with steep slopes arose due to separation of the Caspian Sea from the Aral Sea and increase in their water surface elevations. During the subsequent geological epoch and to our time, division of the united Aral-Caspian into its component parts and its gradual reduction up to the current boundaries took place. At first, the watershed between the Aral-Sarykamysh and the Caspian Sea at Balla Ishem on the Usturt Plateau formed, and then the Uzboy river channel gradually developed. The sequence of desiccation is confirmed by layers of transition deposits from the latest Caspian mollusks burials (along the former Uzboy river, in the sands of the Chilmetkul, and along the south-eastern shoreline of the Caspian Sea) covered by incoherent sands with sparse and young vegetation to ancient formations in the Central Karakum Desert, which have transformed into sors (deposits of super-salty water bodies under drying up), takyrs, compacted sand hills overgrown with woody vegetation. Sors, being the lowest places of the sea bottom and fed by saltish artesian water, kept the pattern of ancient coastal lakes. Since the ancient times, all the researchers and historians were describing transformations of the Aral and Caspian seas depending on water availability and irrigation development in their united drainage basin. They have confirmed the fact of complete desiccation of the Sarykamysh Lake by the end of the sixteenth century, when inflow of the Amu Darya River into the Sarykamysh Lake via the Kunya-Darya, Daudan and Uzboy rivers had stopped. At the section from the Caspian Sea to the Bally Item watershed, the Uzboy channel is lifting by 40 m at a distance of more than 200 km. According to V. Obruchev, the existence of the Sarykamysh Lake took place during the period since the VII century B.C. till the XVI century A.D. On the way to Khiva, in 1559, Jenkinson has observed the presence of the Sarykamysh Lake, which he recognized as the inflow of the Oksus into the Caspian Sea. He also relied on the similar evidences of Abdulghazi-Khan, Ghamdudla and other chroniclers of Khorezm. The Aral-Caspian lowland was sketched out in many maps thoroughly analyzed by Rene Letal and Monica Mainglo in their excellent monograph "Aral". All trends of the Aral Sea migration are tracked in succession of maps drawn in accordance with human perception starting with the “Geography” by Ptolemy (the 2nd century A.D.), on which the Caspian Sea was depicted in all its greatness and without any reference to the Aral Sea (Figure 1), then on the layout of Al Idrisi (1132 A.D.), (Figure 2) and “Catalan Atlas” (1352 A.D.) (Figure 3), where the Aral Sea is sketched out, and ending with the map drawn by Butakov, on which the Aral Sea was already shown in the well-known form (Figure 4).
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