Precursory accelerated Benioff strain in the Aegean area

Abstract

Accelerating seismic crustal deformation due to the occurrence of intermediate magnitude earthquakes leading to the generation of a mainshock has recently been considered a critical phenomenon. This hypothesis is tested by the use of a large data sample concerning the Aegean area. Elliptical critical regions for fifty-two strong mainshocks, which have occurred in the Aegean area since 1930, have been identified by applying a power-law relation between the cumulative Benioff strain and the time to the main rupture. Empirical relations between the parameters of this model have been further improved by the use of a large data sample. The spatial distribution of preshocks with respect to the mainshock is examined and its tectonic significance is pointed out. The possibility of using the results of this work to predict the epicentre, magnitude and time of ensuing mainshocks are discussed and further work towards this goal is suggested.