Monitoring the largest North Korean nuclear explosion 2017, through Indian Seismological Network

Seismological characteristics of the North Korean largest nuclear test of September 2017 have been examined using the data of the In− dian Seismological Network. Full waveform modelling of the ground motion data of Indian stations for this nuclear test shows 16% isotropic component, 47.5% DC and 35.8% CLVD components. The Indian stations being located about 3500 to 5000 km away from the source, gave lesser isotropic component as compared to that from the nearby stations around the North Korean test site. This is attributed to the rapid attenuation of the high frequencies emitted from the source. Its average body wave magnitude, mb from the Indian stations broadly agrees with that reported by worldwide data. It was found that the surface wave magnitude of this test in North Korea was large as com− pared to those from the Kazakistan and Nevada nuclear tests for almost similar mb. It is hypothesized that more powerful fusion pro− cess in the nuclear test could result in larger tectonic slip