Source mechanisms and simulation of ground motions of 18 and 22 July 2014 Suez earthquakes

Abstract

ABSTRACTOn 18th and 22nd of July, 2014, two felt earthquakes have occurred in the northeastern part of Egypt (Cairo-Suez District) near Suez city with magnitude ML = 4.3 and ML = 4.0 respectively. The datasets used involves the two earthquakes recorded by Egyptian National Seismic Network (ENSN) and regional seismic stations (Jordan and Cyprus) to obtain the focal mechanism. A stochastic method is used to obtain high-frequency ground motion synthetics based on local site effect using 5 sites ambient noise (Microtremor) measurements to obtain the resonance frequency of the sediments. The ground motion parameters of (PGA), (PGV), (PGD) and spectral accelerations (SA) of the two earthquakes are obtained. The results show that the maximum value of the peak ground acceleration is observed at the site no. 1 (Northwest the apex of the Suez Gulf) due to near source-site distance and local site conditions (H/V = 4.4), while the minimum value is observed at the site no. 5 (Southwest of the small Bitter Lake) due to a large distance from the source (H/V = 2.10). The damped pseudo-acceleration was applied for the simulation at damping (0.5%, 1%, 5%, 10% and 20%). These results indicated, the efficiency and the importance of the local site conditions on strong ground motions.