Rock Avalanches in the Tibetan Plateau of China

Abstract

AbstractChina is a country with high mountainous areas widely distributed, which is characterized by high reliefs, intensive tectonic activity, fragile ecological environments, etc. Under such particular background, rock avalanches, as one of the most threatening geological disasters in the high mountainous regions, have drawn much scientific interest because of their sudden occurrence, huge volumes (>106 m3), high velocities (>20 m/s), and extremely low Fahrböschung (typically 0.1 to 0.3) with destructive disasters caused. Focusing on the Tibetan Plateau of China, spatial distribution of rock avalanches in its certain area was conducted, hoping to provide insights into the controlling factors of rock avalanches’ formation. Furthermore, several typical rock avalanches were investigated in detail based on remote sensing analysis, mapping of fixed wing unmanned aerial vehicle and detailed field investigations. It is reached that toreva blocks, transverse and longitudinal ridges, ridges separated by conjugate troughs, and hummocks are common and widely distributed surficial landforms in rock avalanche deposits, which usually display in a clear sequential distribution. In the cross-section, a series of internal sedimentary structures, including jigsaw structures, inner shear zones, diapiric structures, convoluted laminations, faults, etc., were identified. Based on these detailed geological features, the possible emplacement processes and mechanisms are discussed to provide insights into the extremely high mobility of rock avalanches.