A. Ismail¹

¹National Research Institute of Astronomy and Geophysics (NRIAG)

Abstract:

Accuracy of the hypocentral location of Aswan seismic events is not satisfactory and was one of reasons for upgrading the local Aswan Seismic Network (LASN). LASN is now composed of 23 filed stations distributed in a relatively narrow area (80 km X 80 km) south of Aswan High Dam. The network provides data as digitally-recorded waveforms of seismic events.This study aims to improve the hypocentral location accuracy based on waveform analysis by applying the Cross Correlation method. Results demonstrate that there are ± delays in the P-wave and the S-wave arrival times of the examined events in relation to the master event at the same station (i.e., Δ Pt ranges between 0.15 and 0.11 second, while Δ St ranges between 0.17 and 0.11 second). The reason for this could be an error in the manual picking of arrival times. We assumed that the P- and S- velocity distribution remains constant during this sequence of events. Relocated events are more closely distributed around the master event. This demonstrates that they originate from almost the same location, rather than the zone identified from the preliminary locations based on manually picked onset times.