Discrimination of Seismic Sources Using Israel Seismic Network
Final rept. Jun 95-Oct 97
INSTITUTE FOR PETROLEUM RESEARCH AND GEOPHYSICS HOLON (ISRAEL)
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We addressed the problem of automated event discrimination in both the local and teleseismic ranges using the Israel Seismic Network, as an example of a dense regional seismic network. A new high resolution technique was developed, based on multistation representation of the seismic signal spectral semblance, measuring coherency of spectral shapes, and velogram, characterizing kinematic features. Semblance and energy spectral ratio statistics, applied to a wide variety of local and teleseismic events, showed, for specific spectral bands, almost total separation of explosions and earthquakes. Efficient automated classifiers based on combinations of different physical features of the events have been designed. The discrimination results for the teleseismic data were compared for the ISN and NORESS, showing almost equivalent performance. Noise recordings and teleseismic signals were used to evaluate the ISN detectability by array technique, including adaptive beamforming, optimal detectors, maximum likelihood estimators and phase correlation analysis, applied to the ISN subnetworks with promising results. Experimental relationships between charge weight and magnitude for local single quarry shots and underwater Dead Sea explosions with outstanding high coupling were developed, providing a basis for the execution of effective calibration explosions currently lacking in the region.
- Seismic Detection and Detectors