Geophysical Investigations Of Seismically Induced Surface Effects: Case Study Of A Landslide In The Suusamyr Valley, Kyrgyzstan

In summer 1998, a geophysical survey including seismic profilesand electrical tomography has been carried out in the Suusamyr valley, Kyrgyzstan. The scope wasto investigate surface effects induced by the Ms = 7.3 Suusamyr earthquake, the 19th of August, 1992. Inthis paper, special attention is paid to the case study of a debris slide triggered by the earthquake.Seismic data are analysed by P-wave refraction technique and by surface wave inversion. Electrical tomographicprofiles are processed by 2D-inversion. Using geotechnical and geological information, P-velocity modelsand resistivity sections are interpreted in terms of geological materials, in order to build a geological3D model. On the basis of the latter, we carried out static finite element computations as well as staticand pseudo-static calculations with Janbursquos method. Newmark displacement was computed, considering or notthe influence of the shallow soft deposits. The results are compared to the real displacementobserved in the field and conclusions are drawn about the mechanism of the landslide.