Pure and Applied Geophysics

, Volume 176, Issue 11, pp 4729–4760 | Cite as

Present-Day Stress Field in Egypt Based on a Comprehensive and Updated Earthquake Focal Mechanisms Catalog

  • Sherif M. AliEmail author
  • Hazem Badreldin


The present-day stress field in Egypt has been investigated on the basis of updated earthquake focal mechanism catalog covering the period from 1951 to 2017. Our catalog contains 234 focal mechanisms compiled from previous studies in addition to 22 new source mechanism solutions achieved in this study. According to the distribution of the recent earthquake epicentres, Egypt is divided into nine seismotectonic regions. The available fault plane solutions in Egypt demonstrate a spatial variability of source mechanisms, which categorize the study area into three groups. The first group includes Dahshour, Beni Suef, Cairo-Suez district, Northern-Central Gulf of Suez and Southern Gulf of Suez, which characterized by pure normal faulting mechanism to normal faulting with strike-slip component. Pure strike-slip faulting has clearly characterised Aswan and Gulf of Aqaba regions in the second group. However, the third group, which contains Abu Dabbab and the northern Egyptian continental margin, is characterized by thrust and strike-slip faulting. To calculate the orientation of the principle stress axes and the shape ratio we have applied the stress inversion technique. The present-day stress regime shows a variability of the tectonic stresses including extensional tectonic, transtensional and strike-slip. The transtensional stress regime with a maximum horizontal extensional NNE stress axis represents the dominant stress field pattern in Egypt. The results exhibit a good agreement with the tectonic settings and recent deformations in Egypt.


Egypt focal mechanism stress tensor earthquakes catalog 



The authors are grateful to the Editor in Chief Prof. Tomas Fischer and the anonymous reviewers for their critical reviews. The authors would like to express their gratitude to Prof. Dr. Ahmed Badawy (Department of Seismology, NRIAG) for his collaboration to improve the manuscript. The authors would like to express their appreciation to the staff members of ENSN who provided the earthquake bulletins to be used in the present study. The authors are thankful to their respective institute (NRIAG) for the continuous and effective support. Generic Mapping Tools (GMT) developed by Wessel and Smith (1998) was used for data mapping.


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© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.National Research Institute of Astronomy and Geophysics (NRIAG)CairoEgypt

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