The main factors of the origin and morphology evolution of underwater canyons in the Southern and Middle basins of the Baikal depression

Abstract

We present the results of morphological analysis of the bottom topography in the Southern and Middle basins of Lake Baikal based on the high-precision bathymetric survey. There is a dominant influence of the fault tectonics at the origin of underwater canyons. Turbidity currents play a great role in the further evolution of the underwater valley. They intensify during abrupt seismic shocks or storm injections into the canyon heads. In cases when canyon heads are close to the river estuaries, terrestrial rivers have a significant impact on the speed of the formation of the canyon valleys. The topography of the original surface often determines the morphological features of the valleys. Climate change in the Pleistocene and fluctuations in the water level of the lake also could initiate the formation of some canyons in Lake Baikal. The studies have indicated the high morphological and genetic similarity of Baikal canyons with marine ones.