Review: This paper demonstrates the results of diatom analysis of the Holocene sediments from the southeastern part of the Tersky Coast of the White Sea. The main subject of the study is the diatom assemblages’ concentration and composition, as well as the ratio of the main diatom ecological groups in sediments. The study sites were located on the Tersky Coast from the village Chavanga to the right coast of the Varzuga River, at heights from 17 to 52 m. Our reconstruction of the Tersky Coast of the White Sea development is based on diatom study of Holocene sediments from three cores. Age was determined according to radiocarbon dating. In this work, the author determines the features of environmental development, starting from the first half of the early Holocene, clarified the age of the main transgressive stages - Folas, Tapes, Trivia and the absolute heights of their marine sediments. According to the changes in concentration and composition  of the main ecological groups of diatoms, the author records the significant trends in the water temperature changes in coastal reservoirs and hydrobiological conditions in the Holocene, such as short-term decrease in the temperatures of the end of Boreal and the first half of Atlantic time, the Holocene hydrobiological optimum, and changes in temperatures of the Subboreal and Subatlantic time.

Keywords: paleogeographic reconstructions, the Holocene, peatbog, radiocarbon dating, diatom analysis, Tersky Coast, the White Sea, sea level changes, Atlantic Waters’ advection, the Arctic

Review: The subject of this research is the correlation analysis of changes in the area of sea ice in separate regions of the Arctic, and levels of internal regional correlations between multiyear monthly changes in the area of sea ice of different seas and the entire Arctic Ocean. The author also examines peculiarities in the annual amplitude course of interannual variability of monthly indices of the area of sea ice for separate districts of the Arctic, interregional links in the annual course of this amplitude of interannual variability, and determination of correlation between the annual indices of the area of sea ice with annual insolation contrast for various Arctic regions. The research method is the correlation data analysis on the area of distribution of sea ice in different districts of the Arctic and insolation contrast. The author builds an algorithm of the value forecast in the changes of sea ice area. Based on the analysis of internal correlations between multiyear and annual changes in the sea ice area in the Arctic regions, and connection with the insolation and insolation contrast, an algorithm is proposed for the value forecast of changes in the sea ice area in separate districts of the Arctic and Northern Hemisphere overall. For long-term forecast of annual values of the changes in sea ice area, the promising districts are Baffin Bay, Kara Sea, Barents Sea, Greenland Sea and Northern Hemisphere as a whole.

Keywords: regional correlation, Arctic seas, prediction algorithm, correlation analysis, insolation contrast, Earth insolation, area change, sea ice, satellite observations, regression model

Review: This article demonstrates the evolution of representation on syngenetic formation of frozen strata set by Lopatin, Abolin, Leffingwell and Nekipelov. It is underlined that the theory of syngenesis is substantiated by the works of Gallwitz, Popov and Katasonov. It is mentioned that Dostovalov proposed a method for approximate determination of the age of ice-wedge ice and calculated that 3m wide ice wedges in the vicinity of Abalakh Lake are older than 2160 years, and 30-40 m high ice wedges in the Novosibirsk islands are older than 12,000 years according to Dostovalov’s calculations. The subject of the detailed study is the meso- and macro- cycles in the structure of yedoma strata in Northern Yakutia. Mesocycles in the yedoma strata of the Zelyony Mys, Stanchikovsky Yar, and Batagay have been examined, along with macrocycles of the Batagay yedoma. The mesocyclicity of the cryolithogenic strata is analyzed in the following cross sections: in Bolshoy Lyakhovsky Island, yedoma in the Belyanka River valley, in the outcrop Soplivaya Gora in the Yana River valley, in the valley of the Vilyuy River downstream of Verkhnevilyuysk, etc. The duration of the mesocycles formation in the yedoma strata of the Northern Yakutia is established: a. One subaquatic-subaerial mesocycle in the Zelyony Mys yedoma consisting of a subaquatic sandy loam and a subaerial peaty horizon of 4 m thick accumulated over the period 3,000years. b. One subaquatic-subaerial mesocycle in the Stanchikovsky Yar yedoma 5 m thick accumulated over the period of 3,300 years. c. One mesocycle in the section Soplivaya Gora, in the Yana River valley with a capacity of 3 m formed for about 3.000 years. Three macrocycles are identified in the Batagay section, with capacity of 7, 10 and 40 m; the time of formation of each macrocycle varied from 15-20 to 40 thousand years or more.

Keywords: Zelyony Mys, Big Lyakhovsky Island, yedoma, permafrost, ice wedge, macrocycles, mesocycles, microcycles, Batagay, Stanchikovsky Yar

Review: The object of this study is the geosystems of gas-saturated permafrost. Currently, the theoretical basis for examination of gas component in permafrost is practically not developed. At the same time, the theoretical and practical significance of this problem has rapidly increased in recent years. This is due to gas emissions during drilling of wells in frozen rocks, the identification of significant greenhouse gas emissions in the Arctic, the detection of previously unknown processes in the permafrost zone – the formation of craters due to gas emissions.The main method applied in the article is the analysis of research materials. The synthesis of the results was carried out on the basis of the geosystem approach. The authors are first to demonstrate that gas-saturated zones in seasonally and permafrost rocks have all the attributes of geosystems: localization in space, boundaries, morphology, individual structure and properties, development history, life cycle, hierarchy. Five types of geosystem were determined: active layer; genetic type; confined to geological structures; secondary, associated with the decomposition of gas hydrates in vivo; technogenic (due to thermal or mechanical effects on hydrated and gas saturated frozen rocks). The artcile describes promising directions in studying gas-saturated geosystems of permafrost zone, as well as  the advanced research methods.

Keywords: frozen rocks, breaking strain, plastic deformation, gas channels, gas filtration, fluids, geosystem of gas-saturated rocks, dissociation of gas hydrates, pressure filtration of gas, stage of development

Review:  
This article is devoted to the mathematical modeling and computing experiment in problems of temperature fields forecast in continuous foundations in cryolithozone, which will provide a qualitative approach to non-stationary thermal calculations for making design decisions to ensure the stability and reliability of bases and foundations of buildings in the Arctic zone.  The article formulates the problem of forecasting by determining changes in the temperature, areal distribution, thickness, and vertical structure of permafrost, seasonal and perennial freezing of the soil, their temperature strength state, and properties in connection with the construction of buildings. Presented mathematical calculations are based mainly on the assumption of a non-stationary process of heat exchange. Mathematical models for determining depth of thawing are considered. The problem of determining the temperature in the basement of the foundation, limited on the one side, in which the temperature depends on only one coordinate with the condition that the surface temperature of the permafrost soil undergoes periodic fluctuations around zero value under the influence of external influences, has been solved. It is demonstrated that the two-dimensional problem of permafrost ground with a semi-infinite foundation thickness can be generalized even more. The problem is formulated in the form of a differential equation of heat balance taking into account the heat flux, which varies according to the Fourier’s law.
 

Keywords: permanently frozen soil, heat transfer, differential equations, control, foundation, ground, temperature field, cryolithozone, nonstationary field, temperature forecast

Review:  
In the areas of distribution of permafrost rocks and development of the ice complex, lake thermokarst is the main relief-forming process, which forms a characteristic alas relief. In addition to the formation of lakes, as a result of thermokarst subsidence, accompanied by water runoff, forms the thermo-sculptured relief including Baydzharakh and hummock-hollow forms. This leads to formation of thermokarst occurrences. The object of this research is thermokarst occurrences, namely, polygonal microrelief and frost splitting, explored in the section of the main water pipeline “Lena – Tuora-Kyuel – Tatta”, near the settlement of Maya Megino-Kangalassky Ulus of the Sakha Republic (Yakutia). These thermokarst occurrences were identified from the satellite images that are publicly available on the Internet. The author also applied processing technique of engineering and geological data, literary and library materials were also used in the work. Field research and simple photography were also used for determining the shape and size polygons. The main conclusion consists in suggesting simple method that allows to conduct area zoning of the territory for activation of the polygonal microrelief as thermokarst occurrences. The research results of area zoning related to distribution of cryogenic processes can be used in technical-economic substantiation of the choice of routes of linear and other constructs.
 

Keywords: main water pipeline, satellite images, underground ice, frost-breaking fracturing, polygonal microrelief, thermokarst, thermokarst manifestations, Central Yakutia, Maya village, technique of zoning