Broadband-seismic analysis of a massive landslide in southwestern China: Dynamics and fragmentation implications

We analyse broadband seismic records generated by the massive Xinmo landslide that occurred in southwestern China at 5:39 on 24 June 2017 (Beijing Time, IJTC + 8). Characteristics of landslide seismic signals, including propagation velocity, duration and frequency contents, are presented and discussed by comparing them with seismic signals generated by a local earthquake of similar magnitude. We perform a long-period seismic waveform inversion in the frequency band of 0.01-0.1 Hz to acquire the landslide force history using 46 seismic traces from 21 seismic stations with distances from the epicentre extending to 360 km. Based on the inversion, we calculate the dynamic parameters of the landslide and recognize its stages and movement characteristics. Landslide basal friction coefficients are also acquired using both a constant dip and varying dips along the slope. A combined analysis of near-field short-period seismic records and dynamic inversion results indicates that the high-frequency energy of landslide signals is most likely generated by rock fragmentations during collision and scraping. (C) 2019 Elsevier B.V. All rights reserved.