Source process of the southeast Beni-Suef, northern Egypt earthquake Using Empirical Green's Function Technique

The rupture process of a moderateearthquake (ML4.9) occurred southeastBeni-Suef, northern Egypt was analyzed. Thecharacterization of the rupture process andsource properties were extracted fromstudying the relative moment rate function(RMRF). RMRFs were retrieved bydeconvolution of small aftershock recordsusing an inversion procedure for onlyP-wave part of the records.Although, this event is a moderateearthquake, its RMRFs exhibitedcomplexity and directivity of the rupturebehavior. The deconvolution pulses reflectthree subevents or more. The detailedanalysis of the distinct subevents revealedgross temporal and spatial characteristicsof the rupture propagation. The azimuthalvariation in the time delay of thesubevents with respect to the initiationrupture indicates that the subevents arelocated at 0.85 ± 0.17 and3.5 ± 0.07 km in directions of320^° ± 45^° and330^° ± 15^° with rupturevelocities 3.4 ± 0.45 and4.0 ± 0.7 km/sec, respectively. Thismeans that the rupture is predominatelypropagated toward the North. Estimation ofthe rupture direction was combined withP-wave focal mechanism to identify thefault plane for the initial rupture ofmainshock.Source parameters were calculated for eachdistinct subevent, including seismicmoments 8.53E14 to 6.80E15 Nm, fault radii713 to 1800 m and stress drops 0.725 to2.932 MPa. The large estimated stress dropfor the main subevent reflects failureasperity.