Brief Communication: The recent seismic activity in Central Greece in 2013 and its precursory electric signals in terms of criticality

Abstract

Here, we check the obedience of new data, derived from the Mw = 5.4 earthquake on 7 August 2013 in Central Greece, to a previously found power law relation by the author between the stress drop of an earthquake and the lead time of its precursory seismic electric signal (SES). An exponent value α =0.329 has been found which is in excellent agreement with previous ones reported in a series of articles by the author. This value falls in the range of critical exponents suggested by various models for fracture and is very close to a reported one which interconnects the amplitude of the SES and the magnitude of the impending earthquake. The stability of this exponent confirms the credibility of the above-mentioned power law and probably implies that real physical dynamic processes evolving to criticality are present in the pre-focal area when the SES is emitted.