Investigation of migratory seismicity in the lithosphere of the Baikal rift zone

Abstract

The study of migrating seismicity was carried out according to data on 52700 earthquakes of representative energy classes KР ≥ 8, which occurred in the lithosphere of the Baikal Rift Zone (BRZ) from 1964 to 2013. M = 2143 quasilinear chains of earthquakes are distinguished and the basic laws of the space-time and energy distribution are established. In the epicentral field of the BRZ seismicity, there are chains of “seismic migration” and chains formed by chance (“pseudo-migration”). To identify the migrating seismicity, the seismic migration activity index (ISMA) was used, which characterizes the seismic migration / pseudo-migration ratio at a given level of significance, obtained maps of the distribution of the index over the territory and graphs of changes over years. The results of the study indicate a direct link between the migrating BRZ seismicity and the location and activation of rifting attractor structures (RAS).