Abstract
The Abu Dabbab seismic zone is located along Egypt’s Red Sea margin, stands out as one of the most active seismic regions in the Eastern Desert. Characterized by frequent micro earthquakes, swarm like activity, and notable historical events. To enhance understanding of its tectonic framework, 408 earthquakes (Ml 0.7–3.0) recorded in 2004 were analyzed using digital waveform data from a temporary local seismic network consisting of ten vertical short period seismometers. Focal mechanisms were determined from P-wave first-motion polarities and classified using ternary plots. The analysis revealed a diverse range of faulting styles normal, strike slip, reverse, and oblique with clear depth dependent patterns. Shallow events (0–5 km) were dominated by normal and strike slip faulting, intermediate depths (5–10 km) showed increased reverse and oblique components, while deeper events (> 10 km) were primarily normal faulting. Stress tensor inversion across three depth intervals indicated a multiphase stress regime: shallow depths exhibited alternating faulting styles due to localized stress variations; intermediate depths revealed a heterogeneous stress field with mixed faulting regimes; and deeper levels showed a dominant normal faulting regime, consistent with the extensional tectonics of the Red Sea Rift. Overall, the stress field is shaped by NE–SW compression and SE–NW extension, with deformation concentrated along NW–SE and NE–SW trending faults. These findings underscore the combined influence of regional rift-related extension and local factors such as magmatic intrusions and crustal heterogeneity in driving seismicity at Abu Dabbab. This study yields important insights into depth dependent stress patterns and active faulting, enhancing seismic hazard assessments and highlighting the region’s potential as a sustainable geothermal energy source within a tectonically dynamic environment.
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The datasets used and/or analysed during the current study are available from the corresponding author upon reasonable request.
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Acknowledgements
Great Thanks to the scientific staff of the Egyptian National Seismic Network Lab. for their invaluable support and for providing continuous facilities that ensured the quality of data and the successful completion of this work. I would like to express special thanks to Prof. Sayed Shaaban, Head of the Egyptian National Seismic Network Lab., Prof. Khaled Abd Ellah Mohamed, and Dr. Mohamed Taha for their exceptional guidance and assistance throughout this study.
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Open access funding provided by The Science, Technology & Innovation Funding Authority (STDF) in cooperation with The Egyptian Knowledge Bank (EKB).
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M.A. wrote the manuscript, and all authors reviewed and approved the final version. M.A. contributed to conceptualization, methodology, software development, data analysis, manuscript review and editing. H.G. The corresponding author is responsible for submitting the competing interests statement on behalf of all authors and contributed to methodology, manuscript review, data analysis and editing. S.E. contributed to methodology, data preparation, manuscript review and editing. S.H. is responsible in data preparation, analysis, visualization, original draft preparation and manuscript review. G.E., M.S., M.Y. and M.H. were responsible for data preparation, analysis, visualization, and original draft preparation.
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Abdelazim, M., Youssef, S.E., Gaber, H. et al. Updated seismotectonic framework of Abu Dabbab Egypt based on focal mechanisms and stress inversion. Sci Rep (2026). https://doi.org/10.1038/s41598-026-36922-3
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DOI: https://doi.org/10.1038/s41598-026-36922-3
