Slope stability analysis in modern hydrothermally active areas

Slope Stability analysis in modern hydrothermally active areas 

Geological Faculty, Moscow State University, Moscow, Russia 

ABSTRACT A big landslide formed on June 3, 2007 in Geyser Valley (valley of the Geysernaya River, Kamchatka, Russia). According to our calculations, the volume of the landslide is 16,31 min m The research showed that the landslide formed in lacustrine-volcanic strata (tuffites, argillites, sandstones). A feature of these deposits is the substantial reduction in mechanical properties due to humidification. Geological and geomorphological conditions predetermined the landslides diffrent types and scales in the Valley of Geysers and adjacent territory. 

Valley of the Geysernaya River is represented as an erosive V-shaped valley depth 300 00 m formed in the eastern part of the Uzon-Geyser volcano-tectonic depression. Sides of the valley have slopes 30-35°. Lacustrine-volcanic deposits forming slopes of the valley are represented interbedded argillites and sandstones with lenses of coarse debris and hydrothermal alteration zones. Strength properties of lacustrine-volcanic formations are dependent on humidification and decrease sharply at water saturation. It should be noted that the formation of the landslide occurred after a heavy snow melt (Dvigailo Melekeszev, 2009). 

Slopes of the valley are complicated numerous landslides and rockfalls, toes of which reach the valley bottom and cause the river sinuosity. As a result of erosion landslide formation, characterized by significant fragmentation and upturned bedding, formed by displacement exposes in the right side of the river. According to the results of this work can be assumed that the leading role in the formation of landscape in the study area played gravitational processes similar to those observed in 2007. 

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