These solid compounds, formed at certain pressure and temperature from methane and water, are mainly found in oceans (in layers located several hundred meters under seabed) and in permafrost areas. It is much more seldom that they are found close to the bottom (several meters below only) within the boundaries of gas-emitting structures which are similar to mud volcanoes. They can be found in the Black, Caspian, Mediterranean and Okhotsk seas and even in fresh water bodies.
It was back in 1992 that experts spoke for the first time of the possible presence of such compounds in sedimentary rock on the bottom of Lake Baikal. The information came from a Russian-American deep-water seismic expedition which investigated the Southern and Central trenches of the lake. A seismic signal known as BSR (Bottom Simulating Reflector) traced deep within the lake several hundred meters of sedimentary rock. This made it possible to anticipate the presence of gas-hydrates in this area.
The year 1998 saw the beginning of Russian-Belgian studies on the Baikal aimed at a detailed assessment of its near-bottom structures. These studies were later described by Prof. Jan Clarx of the Royal Museum of Central Africa (Belgium). In the summer of 1999 the expedition organized by the Institute of Lymnology of the Siberian Branch of the Russian Academy of Sciences, and led by Prof. Mark de Batiste of the University of Ghent (Belgium), investigated the bottom of the lake and sedimentary strata in a trench south of the Selenga delta.
Seismic recordings helped to identify all of the BSR peculiarities and obtain clear outlines of the zone of disintegration of the layer of gas-hydrates along the rifts. Also found at that time were vertical channels through which gas travels along the rifts and reaches the bottom.
At the same time researchers from the All-Russia Institute of Oceanography at St. Petersburg, using a hydro-sounding station of lateral coverage, obtained profiles over the gas emission zon ...
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