Variations and Origin of Fault Activity of Baikal Rift System and Adjacent Territories in Real Time

Abstract

The available geological and geophysical methods fail to estimate variations of fault activity in real time intervals, such as, months, years or decades. Using geo-informational technologies, this challenge can be resolved with an algorithm and software based on a quantitative index of seismic activity. Such an approach has been applied to studies on the Baikal rift system (BRS) and its adjacent territories. It is discovered that fault activity is variable in intervals of several years, which cannot be attributed to changes in regional stress fields. An active fault map of BRS and curves of the quantitative index of seismic activity of faults are constructed for the BRS cross-section. The proposed method ensures a detailed classification of active faults by the quantitative index of seismic activity, and thus significantly extends options for finding solutions of problems related to the middle-term forecast of earthquakes. This method has been applied to study spatial and temporal variations, sources, and mechanisms of the recent fault activation. It is shown that fault activation has a relatively high frequency on the real time scale because of the slow deformation waves of disturbance that are generated by inter-plate and intra-block movements of the brittle lithosphere. Throughput velocity of deformation waves allow classification of active faults into groups that differ in geological and geophysical parameters. They also allow an estimation of the direction of the deformation wave's front and identification of an area of dominating fault activation in real time (geologically instant) intervals.