The role of propagating stress waves on a geophysical scale: Evidence in terms of nonextensivity

Abstract

Laboratory experiments have shown that, during a fracture, the breaking of a bond launches a propagating stress wave which may trigger the breaking of other bonds. We examine here the possibility that the same holds on a geophysical scale. Based on a nonextensive approach, we examine whether the transient stresses of seismic waves from a major earthquake (EQ) can trigger a considerably distant significant EQ. We use three different analytical approaches: (i) a recently introduced fragment-asperity interaction model for EQ dynamics based on nonextensive Tsallis statistics; (ii) the Hurst exponent; (iii) organization in terms of Fisher information. We find that the triggered seismicity displays higher nonextensivity, increased persistent behavior, and a higher level of organization. Using the same approaches, we further elucidate the link between the associated precursory kHz electromagnetic (EM) activity and the last stage of the impending EQ generation. We examine whether the statistics of regional seismicity could be a macroscopic reflection of physical processes in the EQ source, as would be expected by the fractal nature of fracture and faulting.