Chain-Style Landslide Hazardous Process: Constraints From Seismic Signals Analysis of the 2017 Xinmo Landslide, SW China

Landslides generally involve rapid acceleration and deceleration of huge mass in just several minutes, and their unpredictability have made real-time detections of their rapid processes difficult. Seismic signals generated by landslides provide an excellent opportunity to obtain the time-dependent observations on landslide's processes. We invert the force-time function by fitting long-period seismic signals generated by Xinmo landslide on 23 June 2017, SW China, and determine three-stage dynamic processes within 104-s duration of this event. Constrained by the field observed runout distance, we deduce the landslide's mass of about 9 × 10⁹ kg with corresponding maximum velocity and acceleration of 58.8 m/s and 4.38 m/s², respectively. Combining dynamic parameters, apparent friction coefficient, and seismic signal features, we depict a dynamic landslide process initiated by high-position rockslide, traveled by rapid long runout debris, and deposited over an old landslide's deposition fan. The rapid process of the landslide is affected by multiple preconditions such as the structure, topography, and meteorology of the site, which is characteristic of a typical chain-style landslide hazard and could be helpful to recognize potential slope instabilities.