Landslides Triggered by Distant Earthquakes in Central Asia

Abstract

Acquiring data on the triggers of slope failures, such as intensive snow falls, earthquakes and melting snow are essential to understand the mechanism of the failure and predict future natural hazards. Sudden landslides formed simultaneously in different areas triggered by deep foci Pamir-Hindu Kush earthquakes create great danger in the foothill areas of the Central Asian region. The role of distant deep-foci Pamir-Hindu Kush earthquakes as a "trigger" for formation and mechanism in dispersive soils under the influence of prolonged, low-frequency vibrations is examined. Microseismic measurements on 7 landslide sites (by Nakamura method) mainly on landslide sites with a depth of 17-30 m showed the dominant frequency characteristics 1.5-2.2Hz, which coincide with the dominant frequency of deep-focus Hindu Kush earthquakes at these distances from source. Numerical simulation used to assess and comprehend the flow behaviour and some flow-like landslides backcalculated with RAMMS: HillSlope simulation tools.