Evaluation of earthquake activity along the Serghaya fault, Syria, from instrumental seismic data

Abstract

This is a tentative study in order to characterize and identify the Serghaya fault in Syria through an analysis of its instrumentally observed earthquake activity for the period of 1995–2009. Different approaches are used to evaluate a- and b-values of the Gutenberg-Richter relation. It has been found that the computed b-values (around 1.5) are bigger than usually expected, which could be related either to incompleteness of earthquake catalogue or to invalidity of the Gutenberg-Richter model in the case of Serghaya fault. Based on several explanations of high b-values, existing in the literature, it can be inferred that the events recorded on the Serghaya fault occurred at small depths in the heterogeneous milieus under low stresses. A relative seismic quiescence from 1900 up to now is observed, whereas the biggest earthquake recorded during the study period does not exceed magnitude 3.9. Such quiescence does not reflect accurately an earthquake potential of the Serghaya fault and can probably indicate a large-magnitude earthquake occurrence in near future. The established earthquake catalogue must be necessarily completed in order to deeper characterize the real behavior of the Serghaya fault. Such a characterization, accompanied with seismic activity evaluation, could be used in the assessment of seismic hazard.