Abstract
We have relocated 259 inland earthquakes in northern Egypt using the double-difference hypocenter technique. Among this dataset we are able to determine source mechanisms of 200 events using P-wave polarities and amplitude ratios as well. The studied earthquakes have been recorded by the Egyptian National Seismological Network from October 1997 to December 2006 with local magnitude (ML) varies between 1.5 and 5.0. Three earthquake dislocations have been defined namely: Dahshour, southeast Beni-Suef, and Cairo-Suez district. Earthquake activities tend to occur in clusters along the first dislocation (Dahshour) however, relatively scattered along the second (southeast Beni-Suef) and the third (Cairo-Suez district) dislocations. At Dahshour dislocation three distinct clusters have been distinguished. Source mechanism solutions of Dahshour earthquakes displayed normal faulting with a strike-slip component to strike-slip faulting with a minor normal dip-slip component. Most of earthquake focal mechanism orientations are varying from NE-SW to NW-SE. The fault plane solutions of Beni-Suef earthquakes represented normal faulting with a strike-slip component. If the NNW-SSE striking plane has been chosen to be the actual fault plane, some solutions would indicated normal faulting with a sinistral strike-slip motion and other reflect normal faulting with a dextral strike-slip component. The fault plane solutions of Cairo-Suez district earthquakes are compatible with E-W to ENE-WSW striking normal fault with a dextral strike-slip motion.
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Acknowledgments
The authors are grateful to the Associate Editors Prof. Mariano Garcia-Fernandez and Prof. Steinunn Sigríður Jakobsdóttir and the two anonymous reviewers for their critical reviews which have greatly helped to improve the paper. This work has been carried out at Earthquake Division of the National Research Institute of Astronomy and Geophysics (NRIAG), the authors are also grateful to the all staff members of the ENSN.
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Badawy, A.A., AL-Werr, A. & Ali, S.M. Relative location and source mechanism of inland earthquakes in Northern Egypt. J Seismol 18, 257–276 (2014). https://doi.org/10.1007/s10950-013-9378-z
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DOI: https://doi.org/10.1007/s10950-013-9378-z