New insights into the seismic activity of Damascus fault (Syria): a quantitative analysis

Damascus fault is a remarkable reverse tectonic structure trending directly adjacent to Damascus city, and may possibly represent a significant seismic hazard to the city. In this respect, the present work examines the instrumental seismic activity and establishes an earthquake catalogue covering the period 1995-2012 for this important fault, aiming to identify its contribution to the regional seismic hazard. The quantitative analysis reveals the Damascus fault is characterized by low magnitude earthquakes, which implies that the fault could be considered in quiescence status. The analysis exhibit the b-value of Gutenberg-Richter relationship is estimated to be 0.90 using the least-squares method, which could be compatible with a thrust faulting, such as Damascus fault, regarding the published literature. Also, this value could be reasonable for further interpretations. In addition, the return periods of large earthquakes have been estimated to be very long by extrapolation of the established recurrence relationship. Moreover, the maximum regional earthquake magnitude has been estimated by Kijko's procedure as maximum likelihood estimator. This procedure has predicted the maximum possible earthquake magnitude to be 4.2. Consequently, the seismic quiescence, observed actually along Damascus fault, and the estimated long return period implies that a large earthquake could be still so far away.