DYNAMICS OF LAKES OF THE BOLSHOY AZAU GLACIER ON ELBRUS
A.H. Adzhiev1, M.Yu. Bekkiev1, M.D. Dokukin1, R.Kh. Kalov1, E.A. Savernyuk2, S.I. Shagin3
1High Mountain Geophysical Institute, Lenina ave. 2, Nalchik, 360030, Russia
2Lomonosov Moscow State University, Leninskie Gory 1, Moscow, 119991, Russia
3Kabardino-Balkarian State University, Tolstoy str. 175a, Nalchik, 360004, Russia
Keywords: glacier, satellite images, glacial lake, drainage channel, snow cover, lake basin
Abstract
High rates of degradation of the Bolshoy Azau Glacier on Elbrus make it necessary to assess the development of lakes on the ice-free land and on the glacier itself. For this purpose, aerospace data for the period of 1957-2021, as well as information from visual observations, Internet sources, and tourist photographs were analyzed. The existence of 15 lakes with an area of 0.14-20.25 thousand m2 on the Bolshoy Azau Glacier and the adjacent territory was recorded at various times. The long-term existence of the lake in contact with the glacier on the Echo of the War mountain passage covering with an area of up to 4.5 thousand m2 was revealed for the period of 1971-2009. The maximum area (20.25 thousand m2) was detected on a satellite image from June 25, 2009 for a lake on the dead ice part of the median moraine between left and right ice streams of the Bolshoy Azau Glacier. In the hollows on the glacier surface, up to three lakes with a maximum total area of 7.86 thousand m2 were observed in different times. Lakes on the Bolshoy Azau Glacier appeared mainly during the snow cover melting, while masses of drifted snow served as dams in the drainage area of hollows. These lakes disappeared after melting of drifted snow dams and/or in the course of drainage through subglacial and underground runoff channels.
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