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The Ulakhan-Chistay Ridge is interesting by the fact that one of the most extensive mountain glaciations in northeast Russia is located here. In addition, there are widespread specific glacial-cryogenic formations – stone glaciers related to glacial and periglacial processes. On the basis of geoinformation mapping on evidence of remote sensing of the Earth and field investigations within boundaries of the Ridge, 1812 stone glaciers of different morphological types in relation to the enclosing relief were found, among them 111 circus (corrie) and 1701 niche ones. In the group of corrie glaciers, the dominating units are the active forms (76). Some of them are distinctive in the complex structure with different age generations. Among the niche glaciers 948 active, 545 inactive, and 208 relict ones were determined. The analysis of frequency distributions has allowed establishing that the stone glaciers of the studied area are located within the interval of heights 550-2450 m above the sea level. However, the main part of the active formations are positioned at heights of 1500–1900 m. Field observations of stone glaciers were carried out in the upper part of the Kyureter River area that is on the eastern slope of the Ridge. Investigations did show that thicknesses of glaciers at the key area (site) did not exceed 50 m, and they probably consist of several coalesced lobes. Thus, they form polylobate stone glaciers which width may reach 610 m or more with the lobes extending for up to 340 m.

New data on continuing advance of the Kamchatka glaciers Erman, Vlodavets, Sopochny, Schmidt, and Bogdanovich were obtained as a result of analysis of aerospace information taken at different times. Glacier Erman advances during the past 70 years (1945–2016). Over the period from 1949 to 2016, its area increased by 4.7 km2 and the length – by 3.3 km (from 18.2 to 21.5 km). The highest speed of advancing had been estimated for the Schmidt glacier, in 2007–2013 it exceeded 100 m/year. We had identified a new isolated glacier between glaciers Erman and Schmidt, named as the Obvalny (the «Avalanche») glacier, since in 1945 this glacier was buried under volcanic-avalanche deposits resulted from the Klyuchevskaya volcano eruption. In 1975–2016, the Obvalny glacier advanced over a distance of about 1700 m. Also, we had found more 30 ice-rock massifs («wandering glaciers») on slopes of the Klyuchevskaya volcano. Their contours looked like drops or tongues, and some of them advanced in the frontal zone. From 2002 to 2016, the «wandering glacier» in the upper reaches of river Glubokaya (eastern sector of the volcano) advanced for 740 m (55 m/year). Advancing of glaciers here is a consequence of lateral and terminal eruptions of the Klyuchevskaya volcano in XX and XXI centuries. Erman Glacier, glacier advance, Klyuchevskaya volcano, lateral eruption, space images, volcanic and rock avalanche deposits, «wandering glaciers».

In 1967‑2015, Institute of Geography of the USSR/Russian Academy of Sciences together with other organizations carried out field expeditions in different areas of mountain and polar glaciations in many regions: the Polar Urals, Caucasus, Pamir, Zailiysky and Jungar Alatau, Tien‑Shan, Pamir‑Alai, the Kamchatka Peninsula, the Pyrenees, the Arctic – Spitsbergen, Novaya Zemlya, Franz Josef and Severnaya Zemlya, and Antarctica – on the ice flow B, and in the sub‑Antarctic – Islands King George, Galindez, and Livingston. The gravimetric and ground and aerial radar observations were made in these expeditions. About 300 glaciers of different morphological types and sizes with cold, subpolar and temperate thermal regime were studied. Basic results of these studies are the following: (1) the new data on the ice thicknesses, ice volumes, subglacial relief, internal structure, and thermal state of the glaciers were obtained; (2) the two‑layered (polythermal) glaciers consisting of the upper layer of cold ice and the lower layer of temperate water‑filled ice had been revealed in Svalbard for the first time; spatial distribution of cold, polythermal and temperate glaciers had been determined; (3) the evidences were obtained that measured changes in thickness of the upper cold ice layer in polythermal glaciers can be used to estimate the long‑period variations of regional climates and serve as regional paleothermometers; (4) methods for estimating the water content in temperate and polythermal glaciers from the RES data were developed; and its space‑time variations in temperate ices of the Svaldbald glaciers were estimated since even small water content inside of them can noticeably change their dynamic behavior; (5) methods for estimating the ice volume within glaciers in large regions of mountain and polar glaciations had been created; the ice storages were estimated in Svalbard, Franz Josef Land, Dzhungrsky Alatau, the Great Caucasus, and Mt. Elbrus; (6) detailed data on the ice thicknesses and the subglacial relief had been obtained for 40 glaciers in framework of different national and international programs and projects; the data can be used to solve a wide range of practical and theoretical problems, including numerical modeling. These studies demonstrated the following: (1) the use of monopulse radars VIRL‑6 and VIRL‑7 of decameter range (the central frequency is 20 MHz) with digital recording of the radar and GPS data is quite efficient for ground‑based and airborne (from helicopters) radio‑echo sounding of mountain and polar glaciers with their ice thicknesses up to 500–600 m; (2) it was found that thicknesses of glaciers in the Caucasus and Tien Shan can reach 330–430 m, while in regions of mountain, ice‑sheet and transitional glaciation on the Spitsbergen Archipelago – 300, 560 and 600 m, respectively, on the ice caps of the Franz‑Josef Land and Severnaya Zemlya – 450 and 813 m, and on King George and Livingston Islands (Sub‑Antarctica) – 330 and 500 m; (3) large parts of ice caps and outlet glaciers in Svalbard, Franz Josef Land, Severnaya Zemlya which beds were located below the sea level were found. Precisely these parts can be undergone quick shortening due to climate warming, and, thus, cause formation of icebergs making threats for ships and gas‑oil marine platforms in the Barents and Kara seas; (4) data of the measurements made possible to calculate volumes of a number of investigated glaciers and ice caps and to estimate the ice storages in large areas of mountain and polar glaciations (the Jungar Alatau, Great Caucasus, Spitsbergen, Franz Josef Land); (5) decreasing of glacier volumes on the Franz Josef Land and some Spitsbergen glaciers for the last decades had been estimated. Analysis of the data obtained had shown that considerable part of polythermal glaciers in Spitsbergen belong to type of surging glaciers; they have the winter englacial runoff and form the near‑glacier icings. It allows considering such glaciers as dynamically unstable, predisposed to surges as well as possible sources of winter water supply and additional sources of paleoinformation about long‑period variations of regional climate.

From 1957 to 2010, glaciers at the northeast foothills of Elbrus have significantly decreased in size. The area of the glaciers Birdzhalychiran and Chungurchatchiran have shrunk by 5.7 square kilometers. The shrinking in glacier thickness and the reduction in flow of glacier waters have resulted in the formation of barriers that look like riegels; at the same time, barriers that formed by dead ice of the medial moraine disappeared. This situation induced the constant change of glacial flow direction and the breach of lakes. The prediction for this area gives forthcoming radical reforming of the water network because of disappearance of the medial moraine ridge and the joining of the right-hand side of the river Birdzhaly-Su to the merging point of the river Kara-Kaya-Su.

The Koryak Upland, located in Russian Far East, has so far been poorly studied in terms of glaciology. The information contained in the USSR Glacier Inventory (1982) was obtained by analysis of topographic maps and aerial photography. On the publication date, the Inventory of Koryak Upland included 715 glaciers. To study of the current state of Koryak glaciers, we used satellite imageries – Landsat, Terra /Aqua (EOS AM-1) and ASTER. Deciphering the scenes showed that a significant portion of the glaciers melted away since the mid-1970's until now. We have found only 237 glaciers. Some glaciers are appeared to be rock glaciers, filled with detrital material, cemented by ice in a single body. They might be taken for real glaciers while categorization. The analysis of the retreat (reduction in area) of Koryak glaciers by groups with the same morphological type and the same aspect was conducted. The total retreat of the glaciers of this region varied from 40 (for those measured in situ) to 70% (mean total) as compared to aerial photography surveys (1950). This is the most intense reduction among the studied glacier systems of the Russian Subarctic. It can be explained by the changes in atmospheric circulation due to climate change, the Koryak Upland dries out while the increasing of annual air temperatures. Significant reduction of the glacier area was an incentive for us to undertake a work to assess the evolution of the glaciers in the near future. We used a GCM – ECHAM5 (B1) as the climatic scenario. The projection method has got further development: we have estimated the evolution of glacier systems in which the prevailing type is corries (relatively small circus glacier). The results show a diverse picture of glacier reduction by area, but in general the glacierization will not disappear for the period 2049–2060, reducing the extent by only 17% of the contemporary state.

Using instrumental archives, aerial photographs, satellite images, old maps, descriptions of early explorers and old photographs we identified and mapped nine front positions of the Ullukam Glacier (SW slope of Elbrus) for the period from the end of XIX to the early XXI centuries. In 1884–2009 glacier retreated by 775 m. It advanced from 1971 to 1987 (36 m). The glacier fluctuations in the previous period were reconstructed using geomorphologic data, lichenometry, modern and buried soil description and radiorarbon analyses. We identified three Little Ice Age moraines of almost equal magnitude when the Ullukam Glacier was 889 m longer than in 2009. Two later advances occurred in the first third to middle of XIX century and in 1870s The recent fluctuations of the Ullukam Glacier closely correspond to the retreat two other glaciers in Elbus area. The location of the buried soil in the valley of Ullukam glacier brings evidence that the glacier have not advanced lower than 2813 m a.s.l. at least during the last four thousand years.

Residual strength and diameters of lichen Rhizocarpon sp. were measured on different elements of the Late Holocene glacial-cryogenic morphosculpture of frontal parts of glaciers № 29 and 31 in the Suntar-Khayat Range. All in all, 180 lichenometric sites (about 1000 individual measurements of Rhizocarpon sp .) and 150 sites for testing the residual strength of rebound value were organized, on which 380 estimations of this parameter (5674 individual measurements) were performed. For lichenometric index of age (minimal time of exposure) we used statistics RH5 that was a mean value from five maximal individuals on a local site; for index of rebound value Q that was a mean value from 80-100 unit measurements on the same site was taken. Using of data obtained at different times by aerospace surveys made it possible to derive the relationship between the RH5 statistics and time t of the morphosculptures exposure: RH5 = 0.0535 t + 0.29. On the basis of regression coefficients of RH5 and Q indexes the equation RH5 = 69209 e -0,136 Q had been deduced as well as the equation connecting residual strength (rebound value) Q and time t of surface exposure: t = (69209 e -0,136 Qvalue – 0,29)/0,0535. Basing on the equations above, age of the moraine belts of the above glaciers was estimated. The most developed moraine belt, now placed apart from the present-day glacier edges at a distance of 600–700 m, was found to be formed for the whole Little Ice Age. Glaciers reached their maximum volumes during its first phase, i.e. during cold period of 13-15 th centuries. Area of glacierization exceeded its current size by 35–40%. Glaciers remained at their almost steady state until middle of 19 th century and then began to retreat slowly. By middle of 20 th century, glaciers shortened by 5–7%. The most intensive shrinking of these glaciers started in the second half of 20 th century.