ИСТИНА

Europe's largest ice-covered volcanic massif of Elbrus (5642 m) is a unique object for studying the reaction of mountain glaciers to modern climate changes. The feeding areas of the Elbrus glaciers are in conditions of almost free atmosphere, while their languages descend to heights of about 3000 m, covering the maximum diversity of conditions in the entire glacial zone of the Central Caucasus. One of the most important indicators characterizing the regime and dynamics of its glaciers are changes in the speed of ice movement. The estimation of this indicator becomes especially actual in conditions of negative mass balance, observed annually during the last 11 years (2006-2017). In this paper, the data of the radar satellites (Sentinel-1 A and B) and digital terrain models are used to solve this problem. Selected Sentinel interferometric pairs on the Elbrus glaciation area were obtained during the ablation period of 2017. Evaluation of the movement of the glacial surface between the images of each pair was performed using the displacement tracking function in the SNAP 5.0 toolkit. The spatial resolution of the radar data varies from 5 to 20 m. The obtained surface velocities of the Elbrus glaciers range from 0 to 0.6 m/day. The paper analyzes the spatial and temporal variability of this indicator on the basis of comparison with the data of existing ground and remote measurements and gives an assessment of the possibility of using the results obtained in calculations of the mass balance of glaciers in Elbrus. This study is supported by the Russian Foundation for Basic Research, grant 18-05- 00838.