Characteristics of Seismic Sources of Some Asian Earthquakes and Soviet Underground Explosions from Gauribidanur Array Records

摘要

Among one hundred sixty-five shallow-focus earthquakes which occurred over a six-year period (1980-1985) in thirty-five different Asian provinces, Gauribidanur array (GBA) P-wave seismograms of all of them and P/sub c/P seismograms of thirty-one of them from fourteen regions were processed to deduce temporal and spectral characteristics of their sources. These were compared with the corresponding features deduced earlier (Basu and Arora ; 1985, 1986) from eighty-eight known and presumed Soviet underground explosions. The identifiers that yielded wider separation between earthquakes and explosions included among others: (i) cube root of signal complexity per unit TMF (third moment of frequency: CTMF parameter), (ii) spectral energy ratio of P/sub c/P in two distinct frequency passbands (SENR Parameters), and (iii) normalized time-window energy ratio (NTENR parameter) and normalized spectral energy ratio (NSENR parameter) of P and P/sub c/P signals. The last two of these particularly helped to accentuate the main phase and the relative high-frequency content in the P/sub c/P record, which considerably increased the efficacy of the P/sub c/P discriminant. 5 refs., 10 figures, 6 tables. (Atomindex citation 19:018468)