Research Roundup
Systematic identification of seismic signatures from medium-intensity landslides in the Arunachal Pradesh region, Northeast India, and their accurate locations.
Singh RP, Paul H, Laxman B, Rao NP, Borah NK, Venkatesh V, Kumar P.
NATURAL HAZARDS
Seismic identification of landslides is useful for early detection and mitigation. However, most research on this topic focuses on high-intensity landslides (volume > 500000 m3) or rockfalls. For the first time, we have attempted to identify seismic signals from light-intensity landslides (volume < 10000 m3) and their accurate locations in the Arunachal Pradesh region. Using a network of closely spaced broadband stations (average spacing ~3 km) established by CSIR NGRI near Itanagar in June 2022, we identify and validate seismic signals corresponding to a few known landslides and subsequently locate them using a source-migration approach. Seismic locations matched those from satellite-based locations with an uncertainty of ~400 m.
Fig: Field image of one of the landslides that occurred near Itanagar on 19th June 2022, Seismic location of the landslide using data from broadband stations. Location coherence is indicated by a colour scale. The seismogram and spectrogram of the landslide recorded at one of the stations are shown.