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

Stress drop values for fourteen large earthquakes with M(W)> or =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, Deltasigma(B), estimated from far field body wave displacement source spectra and Deltasigma(SB) derived from the strong motion acceleration response spectra. The results show a relation may exist between Brune stress drop, Deltasigma(B), and lead time which implies that earthquakes with higher stress drop values are preceded by SES with shorter lead time.