Gas emission funnels as an object of geocryology (Part 2)

This publication is the second part of an article in which, based on an analysis of available data in scientific literature, the significant role of the cryogenic factor in the preparation of pneumatic explosions within permafrost rock layers is demonstrated. The subject of the research is local cryogenic gas-dynamic geosystems, the development of which leads to pneumatic explosions and the formation of gas emission craters. The focus of the study is the morphology and structure of cryogenic formations in frozen rocks that compose the gas emission craters found in northern Western Siberia. The authors discuss aspects of the topic in detail, such as the analysis and generalization of data on the cryogenic structure of various elements of gas emission craters. Special attention is paid to the examination of cryogenic formations associated with plastic deformations in the upper part of frozen layers and the formation of sub-vertically oriented structures outside the craters, related to the pressurized impact of gas. The primary method used in this article is the analysis of materials from scientific publications on the topic as well as data from laboratory modeling conducted by the authors. The synthesis of the analyzed materials was carried out based on a geosystemic approach. Significant interest is raised by the discovery of ring structures in several craters associated with shear deformations in the edge parts of gas-saturated stocks. The particular interest and novelty of the research lie in the study of cellular ice. These ices and the processes forming them have not been previously considered in geomcryology. They are traced in a narrow zone along the walls of the crater from its bottom to the upper edge of the narrowing part, significantly deformed and separated from the other rocks in the crater by fractures. In the upper part of the crater, the zone of cellular ice integrates into the layered ice-soil mass, forming a stiffness core in the shape of an ice block. Cryogenic formations in the form of cellular ice indicate the forceful impact of rising gas from below on the frozen host rocks. The main conclusion of the second part of the article is as follows: the local gas-dynamic geosystem preparing a pneumatic explosion consists of paragenetically related dynamic cryogenic subsystems, each possessing its own specific cryogenic structure.