OCEANOLOGY
The article investigates the morphometric features of the ice cover lower surface in the Laptev Sea area. The main attention is paid to the study of the hummocked formations’ keel draft and the spatial variability of this quantity.
The data for the research were obtained during several ice seasons (from two to four) in the period 2014-2019 using upward-looking sonars, which were part of the submerged autonomous buoy stations (SABS). The stations were installed at five points in the Laptev Sea area. The data obtained from a series of observations of the ice cover draft allowed extracting information on the hummocked formations’ keel draft at separate points of the sea area. As a result, samples of values of the hummocks keel draft were formed for separate ice seasons for each of the five stations. Further, a statistical processing of the data obtained was performed. In particular, for each of the ice seasons we checked the homogeneity of the mean values and of the distribution of samples by stations. Also checked was the distribution matching. A comparative data analysis using methods of mathematical statistics made it possible to describe the spatial variability of the hummocked formations’ keel draft in the Laptev Sea area for separate ice seasons. The “key” points (stations) describing the spatial variability of the hummocked formations’ keel draft for all the ice seasons considered were determined according to the results of the analysis performed, which allows planning further ice draft research using SABS, if required (to determine the necessary number of stations and points of their installation).
METEOROLOGY AND CLIMATOLOGY
Based on average monthly data from the re-analysis of NASA MERRA-2 satellite measurements, the paper explores climatic changes in the temperature of the upper 1.5 meters of soil (TS), the thickness and area of the snow cover (SC), the moisture content of the top layer of soil 1 meter thick (SM) and air humidity at a height of 2 meters from the surface (AH) in the western part of the Russian Arctic (60°–75° N, 30°–85° E) for 1980–2021. The time interval considered is divided into two periods: 1980–2000 and 2001–2021. The differences between the average values of the parameters studied for these periods are calculated. The climatic changes that have occurred for the winter and summer seasons, as well as for each month of the year, are considered separately. Calculation of linear and quadratic trends has revealed an accelerating growth in the TS of the region studied in the period 2001–2021. A decrease in the thickness of the SC and a significant reduction in the area of the SC in November and April are shown. An increase in SM was found in the southwest and east of the region studied in the period 2001–2021, and a significant increase in AH in the western part of the Russian Arctic over the time interval studied is shown. Moreover, the growth of AH over the waters of the Barents, Kara and White Seas significantly accelerated in 2001–2021 compared to 1980–2000.
GLACIOLOGY AND CRYOLOGY OF THE EARTH
Previously published geodetic mass balance data indicate glacier shrinkage in the Barentsburg area of Svalbard since the beginning of the 20th century on the decadal time scale. However, observations for shorter time spans allowing one to compute the inter-annual variability of the mass balance are scarce. The study presents results of ground-based GNSS and the GPR surveys of the Austre Dahlfonna glacier (2 sq km) located on Spitsbergen island, south of the town of Barentsburg. According to the GPR survey of spring 2019 at 50 MHz frequency, the area-averaged ice thickness was equal to 82 m, while the maximum was 170 m. The results confirm the polythermal structure of the glacier, with a layer of underlying temperate ice. Since the end of the Little Ice Age, the area of Austre Dahlfonna has halved. By comparing the GNSS survey results (the end of the melt season of 2019) with the co-registered archived remote sensing data (ArcticDEM strip of 2013 and S0 Terrengmodell of 2008), it was computed that, within the last 12 years (2008–2019), Austre Dahlfonna lost 16 % of its volume, which corresponds to a geodetic mass balance of –12.05 ± 0.85 m w. e. The mass loss in 2008–2013 (5.22 ± 0.37 m w. e.) was lower than in 2013–2019 (6.83 ± 0.48 m w. e.), which is in agreement with the ongoing direct measurements on the neighboring Austre Grønfjordbreen glacier and with the archipelago-wide mass-balance patterns. We demonstrate that the less intensive glacier mass loss, which occurred in 2005–2012 and was detected previously for the whole archipelago, definitely took place in the Barentsburg area as well. This time interval is characterized by the prevalence of a negative NAO phase (65 % of recurrence), which may indicate more frequent intrusions of colder Arctic air masses. This fact proves that the mass-balance variability of the Barentsburg area glaciers is governed in time spans of 5–10 years by regional-scale factors, presumably by shifts in the atmospheric circulation regimes.
The thawing of polygonal ice wedges determines the dynamics of polygonal peatland relief. The polygonal peat plateaus in the Pur-Taz interfluve account for an average of 6,5 % of the total area. The purpose of the proposed study is to establish the short-term rates and direction of change in the plateaus’ relief under the combined action of technogenic and natural factors, using monitoring data for the period 2005–2022. Based on satellite images and orthophotoplans, elements of the peat plateaus have been outlined and their areas have been determined for different time slices. The studies were carried out on a peat plateau immediately adjacent to the highway (T1) and on a background peat plateau at a distance of about 1.5 km from the highway (T2). To identify the natural causes of changes in the relief of the peat plateaus, the influence of climatic parameters is considered. The rates of relief change in natural conditions and under the impact of the highway are also compared. It has been established that in the area to the north-west of the highway the relief of the T1 polygonal peat plateau has stabilized. In the south-east section of T1, degradation has sharply increased after the construction of the highway. Due to the degradation of the polygons, the polygonal troughs expanded. In the background peat plateau T2, the rate of relief degradation is somewhat higher than in the northwestern portion of T1. Comparison of the main climatic parameters and degradation rates of the polygonal relief did not show any clear correlations. Probably, of greater importance are the regime of atmospheric precipitation, the redistribution of surface runoff and recurrence of flooding and drainage of the polygonal troughs, determined by the rhythmic course of the relief degradation.
ICE TECHNOLOGY
The properties of the ice of natural reservoirs are due to its crystalline structure. The dependence of the mechanical and strength characteristics of single ice crystals on the angle between the direction of application of force to a single crystal and the direction of its C-axis is known. Basically, this dependence is due to the possibility of the base plates of a single crystal of ice sliding relative to each other. In physics, in addition to the mechanical and strength characteristics of a solid, the properties of the surfaces of a solid state, manifested in the process of friction, are of great importance. The friction of two single crystals of ice relative to each other has been investigated in experiments on rest friction and sliding friction. From an artificially grown plate of a single ice crystal, samples of single crystals of ice with a certain orientation of the C-axis were made for the experiment. The measurement of the rest friction coefficient of a single ice crystal was realized according to the classical scheme of recording the minimum angle at which the single crystal began to roll down an inclined surface. The dependence of the rest friction coefficient of ice single crystals on the mutual orientation of the C-axes of single crystals relative to each other was discovered. The coefficients of rest friction in the case that the C-axes of single ice crystals are parallel to each other significantly exceed those obtained when the C-axes of single ice crystals are perpendicular to each other. Measurements have shown that the anisotropy of sliding friction increases with increasing initial velocity of the single crystal on the surface of the second single crystal. This is explained by the fact that with the growth of the path traveled by the M2 crystal, the time of interaction of single crystals of ice also increases, during which the properties of the anisotropy of single crystals of ice relative to sliding friction are manifested. Studies have shown the presence of anisotropy of the friction forces of rest and friction of sliding of a pair of single crystals of ice.
SOCIAL GEOGRAPHY AND SOCIAL ANTHROPOLOGY
The article introduces readers to work on a new research project “Overcoming Uncertainty in Interaction with the Physical and Social Environment in the Russian Arctic” by describing its conceptual and theoretical approach and premises as well as the steps of designing it. It opens with an analysis of the concept of risk, which is currently popular in the Arctic Social Studies and which is sometimes claimed to be the central concept in the field. It proceeds by describing the new approach, which is based on the concept of uncertainty, both natural and social, which constantly accompanies human life in the Far North. The inhabitants of the North know from experience that uncertainty cannot be ruled out, but one can be constantly prepared for it by planning one’s behavior with this factor in mind. Furthermore, one can suggest that the effects of ecological, economic and social changes are experienced by these inhabitants first and foremost as shifts in the level and kind of uncertainty. Therefore, the concept of uncertainty can replace the concept of risk in the studies of the effects of change on northern communities; in fact, “uncertainty” is preferable because its conceived nature is obvious, while in many risk studies, risk is still perceived as something objective. The main questions that a study of uncertainty can answer are: what is the role of natural and social uncertainty in the everyday life of the permanent population of the Arctic? What are the action strategies of the people in the face of uncertainty, including discursive strategies to explain the growing uncertainty? What is the role of state authorities, industrial companies, local organizations, urban and rural communities in overcoming the negative consequences of natural and social uncertainties? How are social connections and networks involved in dealing with situations of uncertainty? The paper demonstrates how these questions can be answered on the basis of anthropological fieldwork. It also uses examples from the Komi Republic (Vorkuta), Yakutia (Chersky settlement), and Magadan area to demonstrate the sort of problems the uncertainty-based approach can contribute to solving. A review of the existing literature in Russian and English is presented in order to give the reader useful insights into the field of uncertainty studies and outline the main directions of research that a study of uncertainty can take
ISSN 2618-6713 (Online)