Seismic Source Locations and Parameters for Sparse Networks by Matching Observed Seismograms to Semi-Empirical Synthetic Seismograms

In this study, we have used a semi-empirical approach to computing synthetic seismograms to demonstrate full-waveform earthquake location and provide size estimates of one nuclear explosion (2006 North Korea Event). The overall approach is to use a known (reference) event to empirically characterize the propagation by comparing the reference event to a synthetic seismogram computed for appropriate. This empirical correction is then applied to a synthetic seismogram computed for a different location and/or source mechanism. Three study areas were used for locations: Central California, Nevada Test Site, and Lop Nor. Events were located to within 5 km of ground truth locations (though in semi-major axes of the error ellipses were greater than 5 km). The approach was also used to estimate the yield of the Oct. 9, 2006 North Korea Nuclear Test using a small 1.2 - 1.5 ton explosion as a reference event. The resulting yield was a chemical equivalent of 372-465 tons. The original document contains color images.