Constraining potential earthquake sources from the geophysical data

Аннотация

The spatial models describing the physico-mechanical properties of the rocks within the seismically active segment of the Altai–Sayan region are constructed from the ground-based geophysical data. The comparative analysis of their probability density functions at the nodes of the spatial grid covering the studied domain and at the hypocenters of the previous earthquakes shows that the bulk and shear moduli are the most efficient markers of the weakened crustal zones, which are prone to earthquakes. The algorithm for constraining the potential earthquake sources based on the spatial distributions of the elastic moduli of the rocks is suggested. When applied to the Taellin segment of the Altai–Sayan region, this algorithm has localized four echelons of the potential source zones of earthquakes at different depths in the crust. The horizontal positions of two of these zones were delineated by the previous studies based on the ground observations of seismicity, whereas the other two zones have been identified by the suggested algorithm for the first time.