Vol. XXVII, No. 2 (March–April 2023)
Full issue:    EC_2_2023_eng_opt.pdf

CONTENTS

GEOTHERMAL FIELDS AND THERMAL PROCESSES IN CRYOSPHERE

  • Lebedeva L.S., Baishev N.E., Pavlova N.A., Efremov V.S., Ogonerov V.V., Tarbeeva A.M. Ground temperature at the depth of zero annual amplitude in the area of suprapermafrost taliks in Сentral Yakutia
    Abstract
    Despite the low mean annual air temperature and low precipitation, subaerial suprapermafrost aquifer taliks are formed in some cases in the continuous permafrost zone of Central Yakutia. The paper presents an analysis of the seasonal and interannual dynamics of ground temperature in contrasting geocryological conditions – in areas of permafrost spread from the surface and in suprapermafrost subaerial taliks – of the key site Levaya Shestakovka 20 km southwest of Yakutsk. The permafrost table in this area occurs at depths from 0.5 to 20 m. The highest ground temperatures are typical of the aquiferous suprapermafrost taliks confined to gentle slopes composed of sandy sediments and covered with pine woodland. The thickness of the seasonally frozen layer reaches 3 m, and the depth of zero annual amplitudes varies from 6 to 12 m. Thawed deposits are preserved due to the continuous filtration of groundwater in them. The lowest ground temperatures are characteristic of the mire and the river floodplain. The depth of seasonal thawing varies from 0.5 to 1.0 m, and the depth of zero annual amplitudes exceeds 15 m. In recent years, slow freezing of the taliks from below has been noted due to mild cooling of the strata underlying the thawed aquifers. Beyond the area of taliks, weak multidirectional changes in ground temperature have been recorded.

SURFACE AND GROUND WATERS IN TERRESTRIAL PERMAFROST REGION

  • Gabysheva O.I., Gabyshev V.A., Yakshina I.A. The chemical composition of water of large East Siberian rivers and its dependence on the thickness of seasonally thawed layer in the catchments
    Abstract
    The main features of the chemical composition and physical characteristics of water in twelve largest rivers of East Siberia (Lena, Vilyui, Kolyma, Aldan, Olenek, Vitim, Indigirka, Amga, Olekma, Anabar, Yana, and Chara) were determined on the basis of observations during summer low-water runoff in 2007–2011. It was found that favorable oxygen regime, relatively high values of the chemical oxygen demand and water color, higher concentration of total iron and ammonium ions, and moderate salinity are characteristic of the studied rivers. East Siberia is a region with a ubiquitous distribution of permafrost. The thickness of seasonally thawed layer within river catchments is extremely variable. Using canonical-correlation analysis, it was found that concentrations of specific components of ionic constituents (water hardness, calcium, magnesium, bicarbonates, sulfate ions, and salinity) depend on the active layer thickness (ALT). Herewith, the deeper the active layer in a catchment, the higher the concentrations of these ionic constituents in river water. This is explained by the fact that permafrost serves as a barrier preventing infiltration of surface water into deep mineral horizons and thus limiting water saturation with mineral ions.

PERMAFROST ENGINEERING

  • Zemlyak V.L., Vasilyev A.S., Kozin V.M., Zhukov D.S. Experimental study of deflections and breaking load on ice reinforced with longitudinal rod elements from polypropylene and fiberglass
    Abstract
    The main features of the chemical composition and physical characteristics of water in twelve largest rivers of East Siberia (Lena, Vilyui, Kolyma, Aldan, Olenek, Vitim, Indigirka, Amga, Olekma, Anabar, Yana, and Chara) were determined on the basis of observations during summer low-water runoff in 2007–2011. It was found that favorable oxygen regime, relatively high values of the chemical oxygen demand and water color, higher concentration of total iron and ammonium ions, and moderate salinity are characteristic of the studied rivers. East Siberia is a region with a ubiquitous distribution of permafrost. The thickness of seasonally thawed layer within river catchments is extremely variable. Using canonical-correlation analysis, it was found that concentrations of specific components of ionic constituents (water hardness, calcium, magnesium, bicarbonates, sulfate ions, and salinity) depend on the active layer thickness (ALT). Herewith, the deeper the active layer in a catchment, the higher the concentrations of these ionic constituents in river water. This is explained by the fact that permafrost serves as a barrier preventing infiltration of surface water into deep mineral horizons and thus limiting water saturation with mineral ions.

  • Gorelik J.B., Zemerov I.V., Khabitov A.K. Preventing the negative impact of flooding on the temperature regime of the frozen base of road embankments
    Abstract
    The article presents the initial assumptions of the predictive model of changes in the temperature regime of the frozen soil massif in the case of surface flooding. Heat exchange of the soil surface with the atmosphere through a shallow (up to 1 m) water cover is described using an effective heat exchange coefficient, which takes into account the intensity of mixing of the water layer in the summer. The results of calculation of two parameters of the new thermal condition of the frozen massif (temperature at a depth of zero annual amplitude and the maximum depth of seasonal thawing) appearing as a result of flooding are presented. In addition, the rate of transformation to the new condition is considered. Significant warming of the frozen base occurs in the case of intense mixing of the water layer during the summer season. If the mixing process does not take place in the water reservoir of a shallow depth, its cooling effect is possible. In deeper reservoirs, the warming effect is possible, but it is weaker than that under mixing conditions. This analysis has been performed for the least studied element of the “roadway embankment – reservoir – frozen soil” technical system in order to control the correctness of the calculation procedure in a more complex case for a two-dimensional process. The results of numerical modeling of the temperature field in the frozen base of the roadway in contact with a shallow water basin are presented. It is demonstrated that the frozen base warms up essentially, if the water layer is mixed intensively (by wind) in summer time. The initial temperature state may be preserved during the whole period of road exploitation, if the summer mixing of water is blocked by fairly simple technical measures that are proposed in this paper.

    SNOW COVER AND GLACIERS

  • Vasilevich M.I., Shchanov V.M. Spatial and temporal differentiation of snow cover parameters in the taiga zone of the Northeast of European Russia
    Abstract
    Data on the snow cover in the middle and southern taiga subzones of the northeast of European Russia (Komi Republic) are analyzed. Field surveys were carried out in the second half of March in 2005–2007 and 2014–2015 on open flat spaces and in the intercrown spaces of forest stands. The studies were conducted at the same monitoring points, which allowed for a correct analysis of spatial and temporal differences. By route observations, measurements of the snow depth and snow density were carried out, and the values of snow water equivalent were calculated. The obtained data were compared with the results of measurements at the stations of the federal meteorological service. Schematic maps of the spatial distribution of snow cover parameters were constructed. The influence of the landscape on snow accumulation was shown: snow depth increased in intercrown spaces of forest stands; in open areas, snow compaction with a decrease in snow depth took place. The wide territorial distribution of measurement points made it possible to estimate the longitudinal effect on the snow cover parameters as related to the corresponding features of the relief. The maximum snow accumulation was observed along the Ural Mountains in the eastern part of the study area, where intense moisture condensation and precipitation take place. Snow depth and snow water equivalent in the foothills increased to the east. At the same time, the zone of increased snow density was noted in the western part of the Komi Republic. The obtained field data are consistent with long-term observations by other authors, as well as with the results of measurements at the network of weather stations.

METHODS OF CRYOSPHERIC RESEARCH

  • Victorov A.S., Kapralova V.N., Orlov T.V. Comparative analysis of area distributions for thermokarst lakes within different types of the surface of thermokarst plains with fluvial erosion
    Abstract
    Thermokarst plains with fluvial erosion include two genetically different types of surface: slightly undulating watersheds with primary termokarst lakes and lowered surfaces of khasyreys (drained thermokarst lakes) with secondary lakes. The research deals with a comparative analysis of statistical distributions of the areas of thermokarst lakes and secondary lakes. Using statistical criteria and remote sensing data for eight key sites in different natural conditions, such as Yamal and Tazovsky peninsulas, the Kolyma Lowland, and the Penzhina River valley, we determined statistically significant differences in the area distributions of thermokarst lakes within different genetic types of the surface. Statistical analysis shows that the areas of thermokarst lakes correspond to an integral-exponential distribution. This allows us to conclude that a dynamic equilibrium is established within each type of the surface in the course of the initiation, growth, and drainage of thermokarst lakes. Though the parameters of thermokarst lakes differ significantly, we find a correlation between the distribution parameters of lake areas within the main surface of thermokarst plains with fluvial erosion and the surface of khasyreys with secondary lakes.

CHRONICLE