Possible relationship between Seismic Electric Signals (SES) lead time and earthquake stress drop

Abstract

Stress drop values for fourteen large earthquakes with M W ! 5:4 which occurred in Greece during the period 1983-2007 are available. All these earthquakes were preceded by Seismic Electric Signals (SES). An attempt has been made to investigate possible correlation between their stress drop values and the corresponding SES lead times. For the stress drop, we considered the Brune stress drop, Á B , estimated from far field body wave displacement source spectra and Á SB derived from the strong motion acceleration response spectra. The results show a relation may exist between Brune stress drop, Á B , and lead time which implies that earthquakes with higher stress drop values are preceded by SES with shorter lead time.

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

“…We remark that events nos. 11, 13, and 15 (Table 2 of Dologlou, 2013) are always excluded from this relation for reasons explained in detail elsewhere (Dologlou, 2008(Dologlou, , 2009). This new exponent 0.329 is in excellent agreement with the previously found one (i.e.…”

“…A series of recent articles (Dologlou, 2008(Dologlou, , 2009(Dologlou, , 2010(Dologlou, , 2012(Dologlou, , 2013 showed an interconnection between dynamic parameters of large earthquakes and features of their precursory SES in terms of criticality. Precisely, a power law relation with an exponent falling in the range of critical values for fracture has been found between the lead time of the SES and the stress drop of the earthquake.…”

Comments on the generation mechanism of Seismic Electric Signals

“…These have been explained on the basis of a model proposed by Dologlou (2008Dologlou ( , 2009Dologlou ( , 2010. It is the objective of this paper to draw attention to the point that new laboratory experimental data (Papathanasiou et al, 2010) considerably support and further strengthen this model.…”

“…with k constant and exponent α = 0.32 lying in the range of critical exponents for fracture, (Sornette et al,1989;Sornette and Sornette, 1990) has been obtained (Dologlou, 2008(Dologlou, , 2009(Dologlou, , 2010. The values of lead time have been recently established in view of the possibility that when employing natural time (Varotsos et al, 2002(Varotsos et al, , 2005, the occurrence time of an impending earthquake can be determined (Varotsos et al, 2006a, b).…”