Wave origin of fault activation in the Central Asia on the basis of seismic monitoring
The generation of earthquake foci in seismically active lithosphere zones is quasi-chaotic. The variation of the spatio-temporal focus migration in real (months, years) time cannot be explained by endogenous variation of the stress-strain state of the medium. In the paper emphasis is put on one of the crucial structural elements governing earthquake foci, namely, on faults of various ranks whose recent activation and seismicity are paragenetically interrelated. From this point of view, using a developed technique we study the spatio-temporal mechanisms of recent fault activation, its sources and occurrence mechanisms. It is shown that the fault activation and its relatively high frequency on the real time scale are induced by slow excitation strain waves due to interplate and interblock shifting in the brittle lithosphere. By the velocity of the excitation strain waves the faults can be classified in groups differing in geological and geophysical parameters. They allow one to estimate the direction of the excitation strain wave fronts and to distinguish the zones of primary fault activation in real (instantaneous from the geological standpoint) time intervals.