Study of Selected Events in the Baikal Rift Zone in a Seismic Discrimination Context.

摘要

Six events from the Baikal rift zone occurring from 1971 to 1975 were examined in a seismic discrimination context. Seismograms from ALPA, LASA, NORSAR, the HGLP, the WWSSN, and the SRO stations were studied for source mechanism, Ms-mb, corner frequency, pP, complexity, and spectral ratio. All the Baikal events can be identified as earthquakes except the November 5, 1976, event which shows explosion characteristics. The characteristics of the Baikal events were compared to six East Kazakh explosions and the Aleutian explosion MILROW. No evidence is found, from the signals studied here, for a zone of high attenuation under the Baikal rift. The discriminants found to be useful in this study, with the possible exception of short-period spectral ratio which is rather unreliable, would not give correct discrimination for a suitable shot array. However there is a full magnitude range of separation in Ms:mb in this region, suggesting that a suitable shot array might be difficult to devise. (Author)