Detection of landslides and submarine slumps using broadband seismic networks

Abstract

We detected 52 seismic events associated with landslides and submarine slumps on 8 August 2009 when Typhoon Morakot hit Taiwan. These events were neither felt nor reported because their seismic energy was primarily in the long period band (20–50 s). Most of these events were located in mountain areas where the accumulated rainfall was extremely high, though some were found offshore southern Taiwan. Among all events, the fatal landslide earthquake was located at Hsiaolin Village, where 474 people were buried. Inversion modelling of the seismic waveforms generated by the Hsiaolin landslide shows that the seismic source was represented by single force, consistent with downhill sliding. Some offshore seismic events indicate that submarine slumps probably occurred along submarine canyons and steep slopes. Our study shows that broadband seismic monitoring can be used to issue early warnings for mitigating disasters generated by inland and offshore landslides.

Brief communication: Post-seismic landslides, the tough lesson of a catastrophe

“…The potential energy released by the event could be estimated, E = 290 TJ , following Lin et al, 2015, and thus the volume involved, V = 13 million m 3 (quite close to the estimation based on field observation and topographic difference), and the average mobilized friction coefficient, µ = 0.29 (following Lin, 2015). For comparison, similar evaluations resulted in E = 150 TJ, µ = 0.12, v = 298 km h −1 , and V = 10 7 m 3 for the 2009 Hsiaolin landslide in Taiwan (Lin et al, 2010Lin, 2015), and E = 55 TJ, v = 101 km h −1 and V = 2.1 × 10 7 m 3 for the 2011 Atakani landslide in Japan (Yamada et al, 2013). Systematic evaluations of landslide characteristics based on seismic recordings are also given by Chen et al (2013).…”

The seismic signatures of the 2009 Shiaolin landslide in Taiwan

“…The long-period seismic signals were recorded by most of the Broadband Array in Taiwan for Seismology (BATS) network and by the F-net in Japan . Lin et al (2010) have identified the location of the Shiaolin landslide using long-period (20-50 s or 0.02-0.05 Hz) band-pass filtered BATS records. They also estimated the source locations of 51 other landslide events from their long-period BATS signals, including submarine slumps that occurred during the typhoon.…”

Evaluating critical rainfall conditions for large-scale landslides by detecting event times from seismic records

“…Recent studies in geophysics (Kanamori et 15 al., 1984;Surin ach et al, 2005;Lin et al, 2010;Ekstro m and Stark, 2013;Chao et al, 2016;Chao et al, 2017) have suggested that the mass movement of large-scale landslides may generate ground motion. If such ground motion is recorded by seismic stations, the occurrence times of large-scale landslides can be extracted from the records.…”