Glaciers are widely recognized as key indicators of climate change. Recent evidence suggests an acceleration of glacier mass loss in several key mountain regions. Glacier recession implies landscape changes in the glacial zone, the origin of new lakes and activation of natural disaster processes, catastrophic mudflows, ice avalanches, outburst floods, etc. The absence or inadequacy of such information results in financial and human losses. A more comprehensive evaluation of glacier changes is imperative to assess ice contributions to global sea level rise and the future of water resources from glacial basins. One of the urgent steps is a full inventory of all ice bodies and their changes. The first estimation of glacier state and glacier distribution on the territory of the former Soviet Union has been done in the USSR Glacier Inventory (UGI) published in 1965-1982. The UGI is based on topographic maps and air photos and reflects the status of the glaciers in the 1940s-1970s. There is information about 28 884 glaciers with an area of 7830.75 km 2 in the inventory. It covers 25 glacier systems in Northern Eurasia. In the 1980s the UGI has been transformed into digital form as a part of the World Glacier Inventory (WGI). Recent satellite data provide a unique opportunity to look again at these glaciers and to evaluate changes in glacier extent for the second part of the 20th century. About 15 000 glacier outlines for the Caucasus, Polar Urals, Pamir Alay, Tien Shan, Altai, Kamchatka and Russian Arctic have been derived from ASTER and Landsat imagery and can be used for glacier change evaluation. Results of the analysis indicate the steady trend in glacier shrinkage in all mountain regions for the second part of the 20th century. Glacier area loss for the studied regions varies from 13% (Tien Shan) to 22.3% (Polar Urals). The common driver, most likely, is an increase in summer air temperature. There is also a very large variability in the degree of individual glacier degradation, very much depending on the morphology and local meteorological conditions.
Changes in sizes of the Klyuchevskaya volcanic group's glaciers had been estimated for the period from 1949–1950 to 2010–2015 using results of analysis of current satellite imagery, data of field observations and historic records. Changes in front positions for some glaciers were analyzed for different periods of time. According to results of comparison between our data and similar ones from the Glacier Inventory the glacier areas decreased by 0.7%. Calculations made with corrected data demonstrated the total increase of the glaciation area by 4.3%. Glaciation of the Klyuchevskoy volcano is characterized by dynamic instability and significant changeability. The Erman glacier, the largest one in this region, did constantly advance since 1945. In 1949‑2015, its area at the front increased by 4.96±0.39 km2, while the front advanced along the valley of the Sukhaya River by approximately 3675±15 m and by 3480±20 m along the valley of the Krutenkaya River. A number of «wandering glaciers» located on the North‑Eastern and Eastern slopes of the volcano, on the contrary, significantly reduced their areas. At the same time, formation of new flows of ice is noticed within the «ice belt». Under the influence of active volcanic processes, the configuration of glacier boundaries on the slopes of Klyuchevskoy volcano does actively change in not only the tongue areas but also in the accumulation areas. Changes in dynamics of the glaciation areas of the Klyuchevskaya group of volcanoes don’t correspond to the present‑day climate changes. The interaction of modern volcanism and glaciation in the area as a whole is conducive to the preservation and development of glaciers, despite the deterioration of climatic conditions of their existence.
On the Kamchatka Peninsula, a number of glaciers are covered by thick volcanic debris, which makes their margins difficult to delineate from satellite imagery. Fortunately, high resolution, multi-temporal digital surface models (DSMs) covering the entire peninsula have recently become freely available (i.e., ArcticDEM). We use these DSMs to analyse the dimensions and dynamics of debris-covered glaciers in the northern Kluchevskoy Volcanic Group, central Kamchatka. This approach demonstrates that between 2012 and 2016, some of the region's glaciers advanced despite regional and local climate warming. These glacial advances are part of a long-term trend, presumed to reflect the role of extensive supraglacial debris in limiting ice ablation, though there is also evidence for local ice melt due to supraglacial lava/debris flows. Glacier surface velocities during the period 2012-2015 were typically 5-140 m yr −1 . Velocities for the major outlets of the region's central icefield were typically higher than for other extensively debris-covered glaciers globally, likely reflecting the influence of ice supply from the high altitude Ushkovsky caldera. In all, we find ArcticDEM useful for analysing debris-covered glaciers in Kamchatka, providing important information on flow dynamics and terminus change that is difficult to derive from satellite imagery.
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