Home – Home – Jornals – Geography and Natural Resources 2023 number 3

Based on analyzing a Digital Elevation Model, we obtained novel evidence for the bottom surface at the junction between the Northern and Southern basins of the South Baikal Depression. The topographic patterns revealed for the north-western slope and the abyssal surface of the site are largely due to high seismic activity and complex fault structural organization of the territory. Fault structures limit the site from all sides, determine the direction of the north-western and south-eastern sides of the site, diagonally dissect its surface, and determine the direction of underwater valleys of canyons, the features of their transverse and longitudinal profiles, the direction and initiation of erosion and gravity processes. Active erosion and gravity processes favored the creation of a well-developed ridge-ravine relief on the slopes of the Posolskaya Bank, the delta-front of the Selenga River and the Kukui Crest. Further to the north, when approaching the surface of the Buguldeika-Selenga bridge, the amplitude of tectonic movements decreases, which has led to a decrease in the depth of the incision and the extent of ridge-ravine forms. On the slopes of delta-front and Kukui Crest, in addition to ridge-ravine forms, landslide structures and concentric forms are of wide-spread occurrence, the formation of which is also associated with active seismotectonics of the territory. It is shown that gas-saturated precipitation plays only a minor role in the intensification of landslide processes on the underwater slopes of the lake. Сatastrophic landslides due to the decomposition of accumulations of gas hydrates at low lake levels and temperatures in modern environmental conditions are unlikely.