Critical dynamic processes prior to destructive earthquakes

Abstract

Earth’s telluric field variations, known as seismic electric signals (SESs), when combined with available remote-sensing technique (GPS) deformation field measurements, can enhance the likelihood of elucidating the underlying physics of the dynamic processes prevailing in pre-seismic regions before fatal failure. The update of a power law relation between the lead time of the precursory SESs and the stress drop in the destructive Mw 6.1 earthquake that occurred in 2014 on Cephalonia Island, Greece, led to an exponent value which agrees remarkably well with those previously obtained and falls within the range of critical exponents for fracture. The stability of this exponent confirms the credibility of the above power law and possibly implies that upon SES emission, non-linear dynamic processes with features of criticality govern the pre-focal area. It is suggested for a future study that a proper combination of remote-sensing techniques with ground-based electric field measures be coordinated in order to verify that a region has entered the critical stage.