Source parameters of the Salmon and Sterling Nuclear Explosions from seismic measurements

The source parameters for the Salmon and Sterling nuclear explosions can be approximated by an equivalent source involving a step function of pressure inside an elastic spherical cavity. The parameters of this theoretical model were determined for Salmon and Sterling by fitting the spectral ratios of the seismic signals. The elastic radius for Salmon is 169 meters; that for Sterling is 29 meters. The ratio of pressures at these radii is about 4. The values of the parameters determined from seismic data are in good agreement with the values determined from gages in the salt dome near the source. The success of this technique suggests that source parameters for small earthquakes might be determined from their spectral ratios. Estimates of the decoupling factor based on this model are in close agreement with values reported in the literature.