Surface-wave and body-wave magnitudes of some Sino-Soviet nuclear explosions and earthquakes

Body-wave and surface-wave magnitudes have been determined for Sino-Soviet nuclear explosions and earthquakes in nearby regions using National Geophysical Research Institute's seismological observatory data. On a Ms versus mb plot, the two are clearly distinguished. The following relations hold good between Ms and mb. M S = 0.70 m b + 1.88 for earthquakes , and M S = 1.06 m b − 1.46 for explosions . A comparison with an analogous study involving only continental seismic paths for North American explosions and earthquakes shows that our findings are consistent for earthquakes whereas for explosions, NGRI Ms values are systematically lower.