The Physical Basis for the Lg/P Discriminant: Signal Characteristics and Modeling
Final rept. 31 Jul 95-31 Jul 97
MAXWELL TECHNOLOGIES INC SAN DIEGO CA
Pagination or Media Count:
Effective monitoring of the Comprehensive Test Ban Treaty CTBT for low-magnitude events can only be achieved through the use of regional seismic observations. One of the most widely heralded regional discrimination techniques is based on the measurement of LgP ratios at regional seismic stations. Although this technique seems to separate events of different source types in many geographic regions, the physical basis for the discriminant and the significance of regional propagation effects on the ratio measurements have generally not been resolved. This study has sought to determine the salient characteristics of LgP ratios as a function of frequency for events of different source types from various geographic regions, to assess how the measurements should have been affected by propagation path conditions, and to analyze the results in terms of physical properties of the seismic source mechanism and the propagation path.