Vol 64, No 4 (2024)

The results of verification of the aerodynamic method for calculating turbulent air heat fluxes between the glacier and the atmosphere using the eddy covariance method are presented. The experiment was conducted on Aldegondabreen, Svalbard, in August 2022. Comparison of the methods showed high agreement between the fluxes estimated by the two methods (R² = 0.7), but the aerodynamic method underestimated the flux (mean error 14%). The eddy covariance method allowed us to estimate the aerodynamic roughness length parameter for Aldegondabreen z_0m = 0.8 mm, and the thermal roughness length z_0h = 0.08 mm. The uncertainty analysis of the aerodynamic method revealed systematic errors related to the wind flow direction. The coefficient of proportionality was 0.67–0.70 for wind direction along the glacier slope and 0.98 for wind direction perpendicular to the glacier slope. Mean values of heat fluxes during the ablation season for the period 1991–2020 were calculated for Aldegondabreen: the short-wave balance is 72.6–113.8 W∙m⁻²; the long-wave balance is 14.5 W∙m⁻²; the turbulent fluxes of sensible and latent heat determined by the aerodynamic method are 20.5 and about 1 W∙m⁻², respectively. Thus, even allowing for a systematic method error of 14% (~3 W∙m^–2), the total turbulent heat transfer value of 24.5 W∙m^–2 was lower than the mean estimates for the short-wave balance.

New data on glaciation of the Orulgan Range in 2013, 2018 and 2023 are presented. By analyzing multi-temporal satellite imagery and historical data, changes in glacier area were estimated from the mid-20th century through 2013, 2018, and 2023, and for the periods 2013–2018, 2018–2023, and 2013-2023. In 2023, the glaciation of the Orulgan Ridge consisted of 58 glaciers with a total area of 7.47±0.85 km². Among the morphological types, corrie glaciers and corrie-valley glaciers predominate. The largest areas are occupied by transfluent-valley and corrie-valley glaciers. The main part (71.8%) of the total area of glaciation in the region is concentrated in the altitudinal range of 1700–2000 m. From the middle of the 20th century to 2023, the area of glaciers registered in the USSR Glacier Inventory and identified in the Russian Glacier Catalog decreased from 16.41 to 7.47±0.85 km², i.e. by 8.94 km² (54.5%). Of these, 5.90 km² were lost from 1951–1967 to 2013, 1.14 km² between 2013–2018, and 1.90 km² between 2018–2023. By 2023, small glaciers with area less than 0.1 km² (84.7%) were the most reduced and largest glacier with area more than 2 km² (12.9%) was the least reduced. The small glaciers of the western aspect decreased most significantly (91.7%). We found a significant increase in the average rate of glacier area reduction in the last 10 years compared to the period from the mid-20th century to 2013: 0.61%/year from 1951–1967 to 2013 to 2.17%/year in 2013–2018, and 4.06%/year in 2018–2023. These changes occurred at the background of a stable positive trend of mean annual air temperature, the magnitude of which is especially large, with acceleration of this process in the last decade.

There are 705 periglacial lakes in Svalbard, formed by glacial retreat after the Little Ice Age. 98 of these lakes, with an area of more than 100 000 m², have river outflow. The rivers flowing from these lakes have significant channel slopes characteristic of mountainous regions. Most rivers flow into fjords. The morphometry of these objects has a characteristic feature: lakes have significant water surface areas, on average about 1.5 km², and rivers have a small length, on average about 2.5 km. To the greatest extent, these parameters correspond to moraine-dammed lakes located in the west of Svalbard. On the example of the moraine-dammed Lake Bretjørna with an area of 1.6 km², it is shown that that the seasonal runoff from it is 2.5—3 times greater than the volume of the lake. Seven lakes have been identified that are of interest for studying sedimentation changes since the Little Ice Age, both in lake basins and in marine estuaries.

The results of observations of the mass balance of the IGAN glacier by the geodetic method using DGPS surveys and constructed multi-temporal digital models of the glacier surface (DEM) for the period 2018–2023 are presented. Comparison with data from previous years (1963, 2008, 2018) obtained using a similar methodology allowed to assess changes in glacier mass over the entire observation period and its features over the short span of the last five years. It was found that the glacier continues to shrink. In 2023, the area of its northern part was 0.43±0.04 km², having decreased by 38% compared to 1963. From 2018 to 2023, the glacier surface dropped by an average of 3.73 m. During this period, the glacier lost 1.593 × 10⁶ m³ of ice. The average annual specific mass balance was negative –627±45 mm w.e. This value is almost twice as high as in the period 2008–2018, when it was –372±63 mm w.e. The cumulative mass balance over five years reached –3134±224 mm w.e. The main cause that determines the glacier shrinkage throughout the entire observation period from 1963 to 2023 is the increase in summer air temperatures occurring on the background of practically unchanged winter precipitation. Along with this, it was found that the glacier lost less over the entire observation period (2018–2023) than in the last three balance years (2020-2023). A possible explanation for this could be the positive mass balance in 2019, in which the DGPS survey could not be conducted. To confirm this assumption, data from meteorological observations of air temperature, precipitation, snow measurement and monitoring of the snow line from satellite images at the end of the ablation period were used. Based on the analysis of these data, a conclusion was made that such a situation was possible due to the anomalous winter precipitation and cold summer in that specific year.

Notwithstanding the fact that the information about the avalanche danger of Kunashir is widely presented in the literature, there is still a certain deficiency of field data on avalanches on the Island. Obtaining data from field observations of avalanche processes on the Kuril Islands would allow us to improve our understanding of avalanches and supplement the existing avalanche hazard maps with new information. Thus, as a result of the expedition performed in April 2022 on the Kunashir, numerous avalanche deposits were described, most of which were recorded in the area between Cape Remontny and Cape Petrova on the south-east coast of the Island. The degree of avalanche activity for the spring season of 2022 in this area is 3 avalanches per 1 linear kilometer of coastline. The maximum volume of deposits does not exceed 300–400 m³. It has been established that on the north-west coast of the central part of the Island from Pervukhina Bay to Sernovodsky Isthmus the geomorphological, climatic and botanical conditions here are very favorable for the formation of avalanches from the ledges of marine terraces. Based on the data on the snow thickness and the areas of avalanche catchments we can estimate the expected avalanche volumes: the maximum volumes are about 500-800 m3, and the average ones are 200–300 m³. We can also judge the high degree of avalanche activity on the coast from Yuzhno-Kurilsky Cape to Gemmerling Cape. The prevailing north-west direction of the winds in the cold season results in the formation of snow-drift sites on the edge of the slopes. The geomorphological factors of the avalanche formation in this area are very favorable and promote snow accumulation and avalanching. Most of the slope is devoid of stands of trees and represented by herbaceous vegetation or completely devoid of vegetation.

In the long-term variability of sea ice extent, a statistically significant negative linear trend was identified for areas of the Greenland and Barents Seas. Using the method of integral anomaly curves, periods of steady increase and decrease in sea ice extent were identified. The period of predominance of negative sea ice anomalies was observed in the Greenland Sea since the winter season of 2000/01, while in the Barents Sea – since the same season of 2004/05, i.e. by 4 years later. The analysis of the age structure of the ice cover showed that old ice predominated in the Greenland Sea throughout the whole winter period, occupying no less than ⅓ of the total ice area. Seasonal maxima of absolute values of the old ice area were observed in December and April. They correspond to two peaks in the seasonal course of ice exchange through the Fram Strait, which determines the amount of old ice in the sea area. The Barents Sea was characterized by the presence of old ice only in the waters of the northern regions, but the amount of them did not exceed 4% relative to the total area of the ice cover. A comparison of the estimates obtained in 1997–2022 with results of earlier studies of the ice age in 1989–1992 for the Greenland Sea, and in 1971–1976 for the Barents Sea, is indicative of a change from a thick (old) ice stage of development to a thinner and younger ice (first-year) and, as a consequence, a decrease in the average thickness of the ice cover. To reveal the dependence of changes in the sea ice area on various hydrometeorological factors, statistical analysis with use of multi-regression models, namely the method of inclusion of variables, was applied. Various hydrometeorological parameters and climate indices were used as predictors. The found regularities made it possible to construct statistical models of long-term variability of the sea ice extent for the winter and summer seasons, the reliability of which is 85–95% with an efficiency more than 10%. The reliability shows the percentage of justified forecasts to their total number (respectively, it is expressed in %). The effectiveness of this forecast method (also expressed in %) shows its preference compared to the climate prediction.

The results of summer and winter surveys of a cave located in the marginal terrestrial part of the Lunny Ice Cap, the Alexandra Land, the westernmost island of the Franz Josef Land Archipelago, are presented. The cave on the Lunny Cap was partially surveyed in the summer of 2023. Due to the danger of collapses, the cave on the Lunny Cap was partially explored in the summer of 2023. The cave was completely crossed and mapped in April 2024. Difficulties in mapping the cave arose due to the strong magnetization of the rocks in the cave and the inability to use a compass. However, the recorded GPS track with low ice thickness above the cave channels made it possible to construct a plan of the cavity. The width and height were recorded at certain points of the track, which allowed to build a plan and a longitudinal profile of the cave. The length of the through channel of the cave was 250 m, the length of the passages was 380 m, the height difference between the entrances was 20 m, average width of the galleries was 9 m and average height was 3 m. The description of the cave is given. Sections with gallery widths up to 12 m characterized by stable arches. Ice collapses from the vaults were typical for sections of galleries of greater width. In winter, collapses stopped due to the frozen ice in the cavity. The cave has existed in any form for at least 18 years. The cave could result from subglacial movement of the channel under the warming effect of the water flow when the glacier bed slopes away from the ice edge. At the same time, the position of the subglacial channel is partially inherits the channel shape formed near the glacier edge during the period when the glacier was retreating.

The position of the Shkhelda valley glacier front (Elbrus region, 43.18N, 42.64 E) for the period from the 1880s to 2022 was reconstructed based on interpretation of aerial and satellite images and old maps. For the first time, the age of the Late Нolocene moraines was determined using cosmogenic isotopes (¹⁰Be) and the results of dendrochronological dating. Judging from historical and cartographic data, the Shkhelda Glacier was advancing in the 1880–1910, when most glaciers in the region gradually decreased in size after reaching their maximum during the Little Ice Age. In the 1880–1920, the front of the glacier was located at an altitude of about 2207 m asl. In the 1920s, the glacier began to retreat, and by 2022 had shrunk by 1.9 km; the altitude of its terminus was 2430 m asl. Left lateral moraines of the glacier, overgrown with pine forest, is indicative of 4 stages of its advance (or stationary positions), which, according to dendrochronological data, are dated to the middle and second half of the XIX century. The terminal moraine corresponding to these stages is dated by ¹⁰Be to 0.16±0.02 ka. Similar date (0.16±0.02 ka) was previously determined for the neighboring Kashkatash Glacier. Two older moraines at the Shkhelda Glacier with the cosmogenic dates of 0.5±0.08 ka and 0.89±0.22 ka apparently had been formed synchronously with the moraines of the Kashkatash Glacier (cosmogenic dates of 0.5 and 0.7–0.8 ka). Evidences of the glacier advance occurred in about 0.7– 0.8 ka were also revealed for the glaciers Donguz-Orun and Chalaati. The older (outer) moraine of the Shkhelda Glacier was formed 1.4–1.6 ka, i.e. approximately simultaneously with the moraine of the Irik Glacier, dated earlier by the same method of the cosmogenic isotope analysis. All cosmogenic isotope dates, determined for the forefield of the Shkhelda Glacier, need to be confirmed, as they are still single, sporadic and isolated. Despite this, they are in a good agreement with other moraine dates; the similarity of the late Holocene fluctuations of the Shkhelda Glacier with the neighboring Kashkatash Glacier is especially significant, notwithstanding the fact that the Shkhelda Glacier is covered with a dense debris cover of the supraglacial deposits, and the Kashkatash Glacier is practically free of it. The anomalous behavior (advancing) of the Shkhelda Glacier in the 1880–1910 is apparently explained by rockfall that occurred in the 1860s, which caused the glacier to be covered by debris and protected it from melting that decreased its ablation.

Less than half of the total number of polar stations that once encircled the northern coast of Russia are currently operating. Regardless of how justified were the decisions to close them, in due time their creation seemed to be necessary both for the country and for the people, on whose shoulders lay extremely difficult conditions for the fulfillment of the task. The fates of each station are individual, and the restoration of the circumstances of their organization and existence can be compared to the addition of lost fragments to the chronicle of scientific exploration of the most difficult for living part of the Earth’s surface. The purpose of the article is to reconstruct an episode related to Russia’s participation in the program of the First International Polar Year. In addition to the Malye Karmakuly station, which had already operated earlier on Novaya Zemlya, it was urgent to organize the second polar station in the delta of the Lena River, which was named after the Sagastyr Island. The chosen place was one of the most understudied, difficult to access and uninhabitable on the Siberian coast of the Arctic Ocean. Nevertheless, in extremely limited time and under the most difficult conditions the station was organized on the specified date and successfully operated in 1882–1884, a year longer than planned according to the program regulations. A comparison of information from various sources and a brief account of the main characters of this event and of those who directly or indirectly influenced the events allow us to look from the perspective of the present time at the circumstances and historical context in which the polar explorers had to operate in the late 19th century.