ИСТИНА

Methane in permafrost Pleistocene and Holocene sediments of the western sector of the Russian Arctic (the coasts and shelves of the Kara and Barents Seas) is a potential factor in forecasting of natural disasters. The identify areas with potentially high risks of natural disasters related to methane emissions is actual scientific task. The solution of this problem will help to decrease the risks associated with industrial development of the Arctic Regions. The effects associated with methane emission from permafrost on global climate system and as a factor potentially increasing the risk of natural disasters are of considerable importance in recent years and bringing attention of mass media, policy makers and scientific community. A striking example is the formation of deep craters as a result of explosive methane emissions in Yamal, Gydan and Taz Peninsula. The nature of these catastrophic phenomena is under discussion in the scientific literature. The forecast of such catastrophic events should be based on comprehensive investigations of methane occurrence and distribution in various types of Quaternary sediments, and on the analysis of changing climatic conditions and other environmental and anthropogenic disturbances that may trigger such catastrophic events. The existing data on methane occurrence mostly available from the permafrost formed in the terrestrial sedimentation environment, however permafrost sediments of the western sector of the Russian Arctic are primarily of marine genesis. Our initial investigations show that methane concentrations in frozen marine sediments is an order or two magnitude higher than in terrestrial counterparts. Abnormally high concentrations of methane are found in ice-wedges and massive tabular ground ice. The key profiles established in Bolvansky Cape (Pechora River mouth), Yamal Peninsula and Western Taymyr. All key profile sections have full representation of the characteristic sedimentation types of sediments formed in the Pleistocene and Holocene. Hazardous areas with potentially high risks of natural disasters related to methane emissions were defined based on the highest observed and projected rate of climate change or temperature of the seabed, and on high methane content in frozen sediments on coasts and shelves. The study is supported by RFFI grant № 16-05-00612.