Fig. 19. Contours of glacier No. 199: a − according to the topographic map, b − according to the image of the Landsat 7 ETM+ sensor of August 31, 2010, c − according to the image of the Landsat 8 OLI TIRS sensor of September 5, 2015 According to the image, d − according to the Landsat 8 OLI TIRS sensor image of September 11, 2020.