Geophysical Journal | 2005 volume 27 1

Tectonophysical analysis of seismic process in zones of active faults of the lithosphere and the problem of medium-term earthquake prediction

© Sherman S.I.

Existing models of seismic process, including those ones based on results of physical modeling of active fault zones, do not consider a multi-level hierarchy of fault structures, their development stages within the zone of destruction when "incidental" merging of any pair of dislocations of the same rank leads to the transformation of almost the whole tree-shaped fracturing pattern. It is shown that the fault-block divisibility of the lithosphere and seismic process may be described by similar equations. A non-stationary model of faults is proposed to explain temporal changes in the seismic process controlled by the conservative fault structure. To estimate the new model, a numerical index of seismic activity of faults is introduced. It gives grounds to conclude that in the seismic zone, earthquakes are controlled by separate seismically active faults, they take place within areas of dynamic influence of the faults and oscillate. In the seismic zone, the seismic process is determined by the behavior of an ensemble of seismically active faults varying in ranks, and specific seismic events occur within the areas of their dynamic influence. Spatial and temporal regularities of reactivation of the ensembles of faults in zone of recent destruction of the lithosphere are established from quantitative indices of seismicity. Their changes within the seismic zone in time and space may give a key to reveal regularities of the seismic process and to predict strong earthquakes. Based on the established regularities, computer modeling should be used to estimate criteria for predicting seismicity in the medium-term scale.

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