Review: This article covers the history of scientific research of the Nizhnekolymsk tundra, conducted over the period from 1970 to 1987 by the employees of the Institute of Biology of the Yakut Branch of the Academy of Sciences of USSR (Yakutsk). The subject of this research is the biochemical composition of plants from the family of sedge and grass – Åãiîðhorum ðîlóstàñhiîn and Arctophila fulva) as the most common communities. It was conducted in tundra pastures in the lower reaches of the Kolyma River for rational economic management. One of the largest state owned farms of Yakutia “Nizhnekolymsky” specializes in reindeer herding – the traditional activity of indigenous peoples, was located in this area. In the past, this area was referred to as Hallerchinskaya tundra; it covered low left bank of the Kolyma River from delta to the forest boundary on the south and Konakovsky uplands in the west. Within the limits of Hallerchinskaya lowland in the rural locality of Pohodsk was located the “Nizhnekolymsky” geobotanical station. The method of models developed by staff members of the Institute of Biology was applied in monitoring the formation of aftergrass and determination of productivity reserve, as well as in selection of quadrats in the subarctic tundra. The main conclusions consists in the statement that the use of the such method for determining the phytomass reserve allowed conducting a prolonged observation over aftergrass formation in the same quadrats, and thereby discerning the natural development process towards reduction or increase of the studied species.

Keywords: phytomass, deer pastures, pingo, polygonal-roller formations, Lower-Kolyma subarctic tundra, Kolyma river, Kolyma lowland, Arctic, Eriophorum polystachion L, Arctophila fulva

Review: This article examines the questions of assessment of the state and dynamics of frozen rocks in the conditions of changing climate on the territory of Tien Shan. The consists in evaluation of geocryological conditions of frozen rocks in Northern and South-Western Tien Shan regions in accordance with the data of regime observations conducted by authors on the equipped stationary sites of high altitude mountain passes. The article provides the results of a set of methods of geocryological and geophysical research, including drilling of engineering-geocryological wells with sampling and determination of the structure and composition of soils, thermometry in wells, geophysical profiling with construction of geoelectric sections. The proposed set of geophysical methods allows stratifying the section, obtain the boundaries of thawed and frozen rocks, as well as follow the dynamics of dangerous cryogenic processes. The geophysical TEM method for work in the mountains features a number of advantages –  the absence of galvanic grounding, mobility of installation, determination in addition to the characteristics of the rock resistance, polarization, the high values of which (according to laboratory data) indicate the presence of ice. The importance of direct observations and geocryological monitoring is emphasized, since in the zones of proliferation of high altitude permafrost, climate warming can lead to the activation of catastrophic processes such as mudflows, outbursts of glacial mountain lakes, landslides, thermal erosion, and thermokarst. Therefore, constant monitoring of the glacial zone is necessary for determination of the new and assessment of the state of the existing foci of hazardous exogenous geological processes. 

Keywords: Monitoring geocryological observations, geophysical research, Tien Shan, permafrost zone, thermometry, stone glaciers, electromagnetic sounding, high mountain permafrost, mudflows, TEM method

Review: The object of this research is the ice wedge casts and concomitant polygonal microrelief. The subject of this research is the delineation of ice wedge casts on the margin of southern exposure of the Lake Churapcha in Central Yakutia. It is a known fact that in permafrost areas, a pronounced polygonal microrelief is a sign of the presence of ice wedge casts. In geology, “delineation” is the outlining of contours and delimitation of boundaries of the deposits, minerals, and zones with different quality of mineral raw materials and mining-geological conditions, according to the data of geological study for rational development. Ice wedge casts and there is such deposit. The article summarizes the results of field engineering and geological surveys conducted in 1995 on the shore slope of southern exposure the lake that contains ice wedge casts. The author also examines the data from modern satellite images for detecting the activation of polygonal microrelief. The surveys of 1995 confirmed the widespread occurrence of ice wedge casts in the indicated district. According to geological section, the ice wedge casts were identified and delineated. The results of section of the bottom of lake-reservoir demonstrate that it is located in the “thawing bowl”. The presence of ice wedge casts is also indicated by a pronounced polygonal microrelief, which is confirmed by satellite images. As a result of climate warming, the upper limit of ice wedge casts may also change, approximately to 0.3 m, which depends on the air temperature, amount of precipitation and depth of seasonal thawing.

Keywords: satellite images, surveys, seasonal layer, permafrost, thermokarst, polygonal microrelief, underground ice, lake, reservoir, Churapcha

Review: The subject of this research is the soil and catena soils in the area of Batagaika crater located in Verkhoyansk District of Northern Yakutia. Soils are usually represented by Cryosols Gleyic and Podzols Entic, which are formed on eluvial and eluvial-deluvial deposits under larch forests. Exploration of soils was carried out in 2017, 2018 and 2019. On the slope to the Batagaika crater is the soil-geochemical catena, which included the ridge-top surface of the slope of Kirgilyah Mountain, the middle part of the slope, as well as levelled surfaces of Batagaika crater. Soil types are described in accordance with the classification of soils of Russia (2004) and the World Reference Base of Soil Resources (2014 WRB). The following conclusions were made: 1) The soil cover in the area Batagaika crater features various types of soils formed on the permafrost rocks, mainly Cryosols Gleyic, found in various landscape conditions, and Podzols Entic are also sporadically distributed in the area. On alluvial deposits in the valley of the Batagaika River may develop Podzols Haplic. Leptosols Lithic are confined to the elevation of the relief with bedrock located close to the surface; 2). The main processes typical for soils in the area of Batagaika crater are: cryogenic structuring, organic matter accumulation, coarse--humus accumulative processes, gleyification; 3) Nearby the horizon of permafrost rocks in the area of Batagaika crater is marked a local minimum of PH level in Podzols and Cryosols.

Keywords: Batagay megaslump, gley-sorption barrier, genetic horizons of soils, heavy metals, trace elements, Entic Podzol, cryosols, Regosols, Verkhoyansk ulus, Yakutia Sakha

Review: Polycyclic aromatic hydrocarbons (PAHs) are the ubiquitous organic pollutants. They are formed as a result of incomplete oxidation of organic substance, for example, technogenic fuel combustion, heating system, wildfires, volcanism, and decomposition of organic residues. Special attention is given to pyrogenic factor of the formation of PAHs in soils. The subject of this research is PAHs in the soils of Batagaika thermoerosive carter in Northern Yakutia in Verkhoyansky Ulus in Yakutia. The author examines the peculiarities of two soil sections (indices B-VG-2019/1 and B-VG-2019/3). Both soils are post-pyrogenic and contain visible traces of a recent fire: embers are found in subsurface horizons of the examined sections, which indicate the recent fire. The following conclusion were formulated: 1) in soils, dicyclic PAHs account for 93%, while the proportions of tricyclic and tetracyclic compounds are roughly equivalent (4% and 3%, respectively); 2) the average values of individual PAHs in the upper (up to 30 cm) and lower (deeper than 30 cm) horizons differ. In the upper horizons, their total concentration is 27 ng/g, while in the lower horizons it is 14 ng/g; 3) in this case, the key biomarker of fires is naphthalene and its homologues. The absence of PAHs with considerable molecular weight most likely testifies to the relatively low fire intensity. The highest values of C/N ratio are noted in the bedding horizon: 10.89 and 3.31, and the lower soils are characterized with approximately 1, which is substantiated by the low content of carbon and nitrogen in the soil profile.

Keywords: two-ring PAHs, pyrogenic factor, soil, carbon, nitrogen, Polycyclic aromatic hydrocarbons, three-ring PAHs, Batagay, Verkhoyansk ulus, Yakutia

Review: The object of this research is the examination of stability of volcanogenic-sedimentary and effusive rocks in the mine workings of Kupol Deposit. The subject of this research is the analysis and assessment of the physical and mechanical properties of these rocks in the solid, considering the intensity of fracturing and the degree of their water content, using the indicators developed by Professor N. S. Bulychev and Professor G. L. Fisenko. The data acquired in real assessment of the state of rock mass prove the choice of applied ground support at Kupol mine. Research methodology is based on the analysis of structural-tectonic peculiarities of Kupol deposit, which defines the high degree of disintegration of complex set of rocks and dictates the need for development of staging approach towards characterization rock stability in mines – from the samples to the full array. The scientific novelty lies in the fact that this work is first to implement phasic approach towards evaluation of stability of the rocks in Kupol mine for transition from the results of laboratory studies of rock samples to assessment of their actual behavior during the exploration of the deposit in severe mining, geological and hydrogeological conditions. It is noted that the Deposit is associated with the volcano-tectonic depression of the Okhotsk-Chukotka volcanic belt, complicated by younger volcanogenic tectonic activity, and is located in the zone of the Middle Kayemraveemsky fault of 1st level of latitudinal outstretch. Analysis is conducted on the implemented system of field development in complex mining and geological conditions.

Keywords: Dome of natural equilibrium, Coefficient of structured weakening, Stress-strain behavior, Permafrost rocks, Structure, Mining method, Support, Competence, Volcanogenic rocks, Ñleavage