Stability of a power law relation between characteristics of earthquakes and electric precursors

Abstract

Abstract. New data were used to test the credibility of a previously reported power law relation between the stress drop of earthquakes and the lead time of precursory SES. Here, we found that the critical exponent of this power law is very sensitive and remains stable around 0.33 only for appropriate sets of data. This value is in full agreement with the reported one in literature for critical phenomena. That means this power law is not an artifact, but probably implies that real physical dynamic processes evolving to criticality are present in the pre-focal area when the SES is emitted. An attempt to advance the underlying physics of the interconnection of the stress drop and the lead time of the precursory SES is still in progress.

Testing the critical exponent in the relation between stress drop of earthquake and lead time of seismic electric signal

“…The application of new data in the power law relation between the stress drop of the earthquake and the lead time of the precursory seismic electric signal led to an exponent which falls in the range of the values of critical exponents for fracture and it is in excellent agreement with a previous one found by (Dologlou, 2012). In addition, this exponent is very close to the one reported by Varotsos and Alexopoulos (1984a), which interconnects the amplitude of the precursory seismic electric signals (SES) and the magnitude of the impending earthquake.…”

“…In a series of recent articles a power law relation between dynamic parameters of earthquakes and associated precursory seismic electric signals (SES) based on progressively updated data has been reported (Dologlou, 2008(Dologlou, , 2009(Dologlou, , 2010(Dologlou, , 2012. Seismic electric signals (SES) are low frequency (<1 Hz) transient signals embedded on the earth's telluric field.…”

Features of criticality in precursory seismic electric signals and earthquakes in Greece

“…., 20, 411-416, 2013 www.nonlin-processes-geophys.net/20/411/2013/ Dologlou, 2008c, a and2009, respectively. (a) for data references for events 1-19 (see Table 1 of Dologlou, 2010 and references therein); (b) for data references for events 20 and 21 (see Table 1 of Dologlou, 2012a andDologlou, 2012b, respectively).…”

“…Second, in Greece a SES activity was recorded in a station located in northern Greece (Varotsos et al, 2012) which was followed by a magnitude 5.7 earthquake in northern Aegean sea. This finding enables the examination on whether the credibility of a power law relation with a critical exponent between the earthquake stress drop (which is the difference between the stress state at a point on a fault before and after the occurrence of the earthquake) and the SES lead time found by Dologlou (2009Dologlou ( , 2010Dologlou ( , 2012a is preserved when these new data are introduced. This critical exponent based on a large amount of data of earthquakes and associated SESs is subjected to a continuous updating and seems to exhibit a remarkable stability and universality.…”

“…During the last preparatory stage of a large earthquake, the preseismic region in the earth's heterogeneous crust is characterized by the general feature of complex systems in a nearcritical state such as long-range correlations, fractal geometry and nonlinear dynamic processes (Telesca et al, 2005;Teotia and Kumar, 2011). A number of recent publications (Dologlou, 2008a(Dologlou, , b, 2009(Dologlou, , 2010(Dologlou, , 2012a showed an interconnection between dynamic parameters of large earthquakes and features of their precursory seismic electric signal, in terms of criticality. Seismic electric signals, termed as SESs, are found to precede large earthquake in Greece (Varotsos and Alexopoulos, 1984a, b;Varotsos et al, 1986Varotsos et al, , 1993 and Japan (Uyeda et al, 2009.…”