Accession Number : ADA317385

Title :   Discrimination of Seismic Sources Using Israel Seismic Network.

Descriptive Note : Scientific rept. no. 1,

Corporate Author : INSTITUTE FOR PETROLEUM RESEARCH AND GEOPHYSICS HOLON (ISRAEL)

Personal Author(s) : Gitterman, Yefim ; Pinsky, Vladimir ; Shapira, Avi

PDF Url : ADA317385

Report Date : JUL 1996

Pagination or Media Count : 97

Abstract : Regional Densed Seismic Networks (RDSN) have additional as yet uninvestigated potential for discriminating weak local earthquakes and quarry blasts. Even conventional single station discriminants, such as P/S and spectral ratios are significantly improved, after averaging across the Israel Seismic Network, which consists of 36 short period stations. This report documents a study aimed at the development of new techniques specially designed for RDSN oriented discrimination: (1) subnet average of the seismic energy ratio between the low (1-6 Hz) and high (6-11 Hz) frequency ranges; (2) spectral semblance, measuring subnet spectral shapes coherency; (3) velogram analysis evaluating the different kinematic features of seismic waves for shallow and deep events. The algorithms were tested on 212 events: earthquakes, quarry ripple-fired and single blasts, and underwater explosions from some areas of the Middle East region with a 97-100% success rate. The study of this physically approved algorithms was complimented by testing of the multivariate procedures based on formal Integrative Approach: King's clustering procedure, Linear Discrimination Function and Artificial Neural Networks. When applied to a vector of spectral parameters derived from the Galilee data base, they provided 99-100% of true classification in a cross-validation test. All the procedures are applicable to routine processing of seismograms, thus significantly improving discrimination performance.

Descriptors :   *SEISMIC DISCRIMINATION, DATA BASES, ALGORITHMS, ISRAEL, NEURAL NETS, MULTIVARIATE ANALYSIS, EXPLOSIONS, SEISMIC DATA, CLUSTERING, SEISMIC WAVES, VECTOR ANALYSIS, EARTHQUAKES, SEISMOLOGICAL STATIONS, SHALLOW DEPTH.

Subject Categories : Seismic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE