Gas hydrates and gas venting in Lake Baikal

In connection with the recent discovery of gas hydrates in Lake Baikal, numerous published materials, which could contain any information on the gas seepage from the bottom sediments, have been investigated. We revealed that in the 1930s, both direct and indirect data showing significant gas venting (presumably methane) in Lake Baikal were obtained. Analysis of these materials indicates that the dates of the ice steamthroughs opening are later and the intensity of gas venting from the ice steamthroughs is lower at present as compared to the 1950s. The events of abundant death of pelagic fish golomyanka (Comephoras baicalensis Pall.) as well as specific forms of the ice cover caused by the methane venting, which used to happen in the lake, has not been recorded in Baikal since the 1950s. Thus, it seems that the intensity of gas venting has significantly decreased for the last 50-60 years. This may be due to lowering of the number of catastrophic (M = 9-10) earthquakes in the Baikal region.