DOI: 10.7256/2453-8922.2022.1.37722

Abstract: The article is devoted to the consideration of surface and deep factors that trigger the mechanisms for the preparation of explosive processes that form gas emission craters. The study object is local zones of gas-saturated soils with abnormally high gas pressure and gas craters. The main method used in this article is the bibliography review. The synthesis of the analyzed materials was carried out based on the geosystem approach. In the proposed work, an analysis was made of the main hypotheses of the formation of gas-saturated zones with increased gas pressure in frozen soils: 1) due to the comprehensive freezing of taliks (completely dependent on surface conditions; 2) due to the inflow of warm gas from underlying rocks into the surface layers (depending on deep sources); 3) due to the decomposition of gas hydrates contained in the permafrost (the reasons can be both surface and deep); 4) due to the joint interaction of the freezing talik and the associated deep gas inflow channel. Possibilities of realization of these or those hypotheses in real conditions are revealed. The relevance of the topic is due to the reassessment of the role of frozen soils as a screen that protects the atmosphere from the emission of greenhouse gases from the lithosphere. Evidence has appeared that this role of the cryolithozone is significantly weakened with an increase in temperature, while the frozen soils themselves can be a source of gas release.

DOI: 10.7256/2453-8922.2021.3.35505

Abstract: The subject of this research is frozen rocks that compose gas emission funnels in the north of Western Siberia. The object of this research is the cryogenic factor that causes the formation of gas emission funnels. The authors substantiate the thesis that gas emission funnels are cryogenic phenomenon, and the processes preparing the explosion cannot be accurately interpreted without taking these features into account. The analysis of research materials on gas emission funnels, discovered in the north of Western Siberia, allows concluding that surface conditions may have a significant impact upon the formation of gas emission funnels. Special attention is given to consideration of the hypothesis of formation of gas emission funnels due to local heat penetration and gas supply from the depth. The necessary conditions are described. The article provides the examples of using geophysical methods for detecting of gas supply channels. It is concluded that gas emission funnels are the result of self-development of fluid-dynamic geosystems, which represent local, ice subsurface gas-saturated formations that are in a inequilibrium thermodynamic state with respect to the enclosing permafrost formations. The authors' special contribution consists in examination of the external and hidden mechanisms of the emergence of inequilibrium conditions od the mechanism that launches an explosion. The novelty of this research lies in the development of technique for determining the processes that cause the emission of underground gas, based on the analysis of cryogenic formations, which compose the walls of gas emission funnels.

DOI: 10.7256/2453-8922.2021.2.35500

Abstract: The subject of this research is the cryogenic formations found in gas emission funnels in the north of Western Siberia. The object of this research is cryogenic processes that prepare the explosion, which forms a gas emission funnel. The study of cryogenic structures that shape the walls of gas emission funnels is based on the structural-genetic analysis, which reveals the peculiarities of the initial cryogenic structure of frozen rock, as well as the cryogenic textures modified as a result of dynamic metamorphism. The authors examine such aspects of the topic as the general orientation of plastic and explosive deformations under the influence of high pressure. Analysis is conducted on the role of intra-ground gas filtration in transformation of the initial cryogenic structure. Special attention is given to the patterns of emergence and development of the local geodynamic system that ultimately substantiates the formation of gas emission funnel. The novelty of this research consists in the establishment of paragenetic relations between the processes of gas filtration and deformations of gas-saturated ice surface material (from viscoplastic motion to brittle fracture). The main conclusions are as follows: such external influences as increase in the temperature or pressure change thermodynamic conditions, which lead to multi-phase structural transformation of the initial cryogenic structure of the cryolithic zone; a series of plastic and explosive deformations instigates the intense heat and mass transfer, redistributing the substance in the liquid, solid and gaseous state; in frozen rocks, ice is the most deformable component, thus, most information on the processes preceding the formation of gas funnels can be acquired by studying the morphology of cryogenic formations observed in the walls of the funnels, as well as in the unthawed fragments of frozen rocks thrown to the surface. The authors’ special contribution lies in examination of the complete lifecycle of the development of selected geosystems, from the initial stage –  formation of conditions for decomposition of the gas hydrates, to the final stage – explosion and emission of ice surface material.

DOI: 10.7256/2453-8922.2020.2.32698

Abstract: 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.

DOI: 10.7256/2453-8922.2018.3.27524

Abstract: The subject of this research is the gas emission crater (Yamal crater), located in the southern part of Bovanenkovo deposit on the Yamal Peninsula. Generalization of data on the structure of crater soils components, natural conditions and laboratory results, allowed building a phenomenological model of the Yamal crater, with identification of different stages of its development. The cause for the emergence of the gas emission craters is the formation within the subsurface of permafrost rocks of the underground gas accumulation zones with the abnormally high pressure. The diverse geological and thermodynamic factors substantiate the various scenarios of their development. The main research method lies in consideration of the different structural elements of the Yamal crater as the phenomena that reflect the processes of its formation. In determination of the processes that form the gas emission craters, the authors apply the method of analogies. The conclusion is made that the gas emission craters eventuate the self-development of the fluid dynamics geosystems, which are the local ice-surface gas-saturated formations in non-equilibrium thermodynamic state in relation to the enclosing permafrost rocks. The development of the selected geosystems is defined by paragenetic links between gas filtration processes and deformations of gas-saturated ice-surface material (from viscoplastic motion to brittle fracture). The Yamal crater is a particular example of a full and complete life cycle of the development of selected geosystems: from the initial stage – the formation of conditions for decomposition of gas hydrates, to the final stage – the explosion and release of ice-surface material.

DOI: 10.7256/2453-8922.2018.2.26319

Abstract: This article is devoted to the consideration of issues related to the formation of local zones with signs of dynamic metamorphism in permafrost. Data on the cryogenic formation structures with traces of plastic and discontinuous deformations, as well as signs of flow in a solid, liquid and gaseous form are analyzed. The possibility of using the fluid dynamical approach in the study of dynamic processes in the cryolithozone is considered. The development of the fluid dynamic topic necessitates consideration of non-traditional geocryological objects associated with fluid formations in the cryolithozone. The main attention is given to the structural method associated with the analysis of the features of the cryogenic formations structure and the method of actualism associated with the analysis of the conditions for the fluids formation. In the first part of the article, the paragenetic relationships between the features of the frozen soils formations on the Arctic coasts, the formation of inland water flows and the structural and texture features of the cryogenic formations are considered. A section of marine sediments in the area of the Nei-To lake in Central Yamal was chosen as the research object.

DOI: 10.7256/2453-8922.2018.2.26377

Abstract: The second part of the article is devoted to the consideration of the conditions for the development of two types of fluids in permafrost: frozen soils, and ice flows and gas flows. This work is hampered by the lack of a corresponding conceptual and terminological base, developed classifications, systematized features, differentiation of genetically distinct dynamic formations in frozen soils. In this work, the conceptual fluid dynamics terminology used in geology is analyzed and the possibility of its use in geocryology is considered. The main attention is concentrated on the construction of phenomenological models for the fluids formation in permafrost, supplemented by the structural method and by the method of actualism. The conditions for the development of various types of lithogenous fluids are analyzed: through the formation of a nucleus of rigidity, the motion of frozen soils along the slope, subaquatic landslides, and folding at the lateral surface of growing ice wedges. Based on the analysis of the structure of the gas emission crater (Yamal Crater), the possibility and conditions of gas filtration through icy frozen soils are considered. A mathematical model of the pressure filtration of gas fluids in structurally heterogeneous soils is proposed on the basis of the Brinkman equation applied to the frozen soils.