Arabian Journal of Geosciences

, Volume 7, Issue 11, pp 4553–4562 | Cite as

Study of the 26 December 2011 Aswan earthquake, Aswan area, South of Egypt

  • Ahmed HosnyEmail author
  • Sherif M. Ali
  • Azza Abed
Original Paper


The source process and parameters for a moderate earthquake of magnitude Ml 4.1 that occurred on the Kalabsha fault at the Aswan area are analyzed. The derived focal mechanisms of this event and other two aftershocks using polarities of P, SV, and SH waves show strike-slip fault with minor vertical movement of normal type. The solutions give two nodal planes trending ENE–WSW and NNW–SSE in close agreement with the surface traces of the faults crossing the area. The movement is right lateral along the first plane while left lateral along the second one. The rupture process characterization of this event has been investigated by using the empirical Green’s function deconvolution method. By inversion only for the P wave part of the records of these three events (main and other two aftershocks), the source time function for the master events and the azimuthally variations in the (RSTF) pulse amplitude are retrieved for estimating the rupture directivities. The estimated rupture direction is combined with the P-wave focal mechanisms for the three events to identify the fault plane solution for these earthquakes. Based on the width, amplitudes, and numbers of the isolated source time functions, a complex bi-lateral rupture of the studied earthquake is delineated. The source parameters of the master event is calculated and the derived corner frequencies f o for P-wave spectra show a value of 6.6 Hz; the seismic moment (M o ) is 4.2 × 1022 Nm; the average displacement (U) is 0.5 m; fault radius (r) 40 m; the average value of the stress drops (Δσ) is 0.6 Mpa, and the moment magnitude (M w ) is 4.4.


Aswan earthquake Rupture process Focal mechanisms Source parameters 



The authors would like to express their gratitude and appreciation to their colleagues at the Seismology Department, Egyptian National Seismological Network ENSN, who analyzed the waveform of the Aswan earthquake to be used in the present study. Furthermore, in advance, the authors express their gratitude to the anonymous reviewers.


  1. Abdel Fatah AK (1999) Source characteristics of the 28th January 1999 Nagano earthquake. Jpn IISEE 35:45–57Google Scholar
  2. Abdel-Fatah AK, Badawy A (2002) Source process of the southeast Beni-Suef, northern Egypt earthquake using empirical Green’s function technique. J Seismol 6:153–161CrossRefGoogle Scholar
  3. Abercrombie RE (1995) Earthquake source scaling relationships from −1 to 5 ML using seismograms recorded at 2.5-km depth. J Geophys Res 100:24015–24036CrossRefGoogle Scholar
  4. Abou Elenean K (1997) Seismotectonics of Egypt in relation to the Mediterranean and Red Sea tectonics. Ph. D. thesis Ain Shams Univ., EgyptGoogle Scholar
  5. Abou Elenean KM (2007) Focal mechanisms of small and moderate size earthquakes recorded by the Egyptian National Seismic Network (ENSN), Egypt. NRIAG J Geophys 6:119–153Google Scholar
  6. Awad H (1994) Investigation of the tectonic setting, seismic activity and crustal deformation in Aswan seismic region, Egypt, Ph.D. Thesis, Tokyo University (unpublished)Google Scholar
  7. Awad H (2002) Seismicity and water level variations in the Lake Aswan area in Egypt 1982–1997. J Seismol 6:459–467CrossRefGoogle Scholar
  8. Awad H, Mizoue M (1995) Earthquake activity in the Aswan region. Egypt Pageoph 145:69–86CrossRefGoogle Scholar
  9. Awad H, Mekkawi M, Hassib G, Elsaid M (2005) Temporal and 3D spatial analysis of seismicity in the lake Aswan area, Egypt. Acta Geophys Pol 53(2):153–166Google Scholar
  10. Brune J (1970) Tectonic stress and the spectra of seismic shear waves from earthquakes. J Geophys Res 75:4997–5009CrossRefGoogle Scholar
  11. Brune J (1971) Correction. J Geophys Res 76:5002CrossRefGoogle Scholar
  12. Choy GL, Boatwright JL (1995) Global patterns of radiated seismic energy and apparent stress. J Geophys Res 100:18205–18228CrossRefGoogle Scholar
  13. El-Hady SM, Khalil AE, Hosny A (2004) 1-D velocity structure in Northern of Aswan Lake, Egypt deduced from travel time data. J Appl Geophys 3(1):55–62Google Scholar
  14. Ellsworth WL, Beroza GC (1995) Seismic evidence for an earthquake nucleation phase. Science 268:581–855CrossRefGoogle Scholar
  15. Elshazly EM (1977) The geology of the Egyptian region. Ocean Basin Margins 145:193–207Google Scholar
  16. Fat-Helbary R, Tealeb A (2000) A study of seismicity and earthquake loading at the proposed Kalabsha Dam site, Aswan, Egypt. Bulletin of NRIAG, vol B, pp 39-61Google Scholar
  17. Frankel A, Fletcher J, Vernon F, Haar L, Berge G, Hanks T, Brune J (1986) Rupture characteristics and tomographic imaging of ML = 3 earthquake near Azna southern California. J Geophys Res 91:12633–12650CrossRefGoogle Scholar
  18. Hartzell SH (1978) Earthquake aftershocks as Green’s functions. Geophys Res Lett 5:1–4CrossRefGoogle Scholar
  19. Hassib GH (1990) A study on the earthquake mechanics around the high dam lake, Aswan, Egypt, Ph.D. Thesis, Faculty of Science. South Valley University, SohagGoogle Scholar
  20. Hassib GH (1997) A study on the earthquake mechanics around the High Dam Lake, Aswan, Egypt. Ph.D. Thesis, Faculty of Science. South Valley University, SohagGoogle Scholar
  21. Issawi B (1978) Geology of Nubia, West area, Western Desert, Egypt. Annals Geol Surv Egypt 3:327–392Google Scholar
  22. Issawi B (1982) Geology of the southwestern desert of Egypt, Ann Geol Survey EgyptGoogle Scholar
  23. Kebeasy RM, Gharib AA (1991) Active fault and water loading are important factors in triggering earthquake activity around Aswan Lake. J Geodyn 14:73–82CrossRefGoogle Scholar
  24. Kebeasy RM, Tealeb AA (1997) Earthquake activity and subsurface structures of south valley project., internal report, NRIAG, 14: 27pGoogle Scholar
  25. Kebeasy RM, Maamon M, Ibrahim EM (1982) Aswan Lake induced earthquake. Bull Intern Inst Seismol Earth Eng Tsukuba 19:155–160Google Scholar
  26. Kebeasy RM, Maamoun MM, Ibrahim EM, Megahed A, Simpson DW, Leith WL (1987) Earthquake studies at Aswan Reservoir. J Geodyn 7:173–193CrossRefGoogle Scholar
  27. Khalil AE, El-Hady SM, Hosny A (2004) Three-dimensional velocity structure of VP and VP/VS around Aswan area, Egypt. J Appl Geophys 3(1):303–314Google Scholar
  28. Li Y, Thurber CH (1988) Source properties of two microearthquakes in Kilaauea volcano, Hawaii. Bull Seism Soc Am 78:1123–1132Google Scholar
  29. Li Y, Doll C, Toksov MN (1995) Source characterization and fault plane determination for Mblg = 1.2 to 4.4 earthquakes in the Charlevoix Seismic Zone, Quebec, Canada. Bull Seism Soc Am 85:1604–1621Google Scholar
  30. Mahmoud S M (1994) Geodetic and seismotectonic deformation near Aswan reservoir, Egypt. Bulletin of CRCM No.41. Praha, Czech Republic. Pp 5-30Google Scholar
  31. McGarr A, Fletcher JB (2002) Mapping apparent stress and energy radiation over fault zones of major earthquakes. Bull Seismol Soc Am 92:1633–1646CrossRefGoogle Scholar
  32. Mekkawi M, Grasso J-R, Schnegg P-A (2004) A long-lasting relaxation of seismicity at Aswan, Egypt, 1982–2001. Bull Seism Soc Am 94:479–492CrossRefGoogle Scholar
  33. Mekkawi M, Abdel-Monem SM, Rayan A, Mahmoud S, Saleh A, Moustafa S (2008) Subsurface Tectonic Structure and Crustal Deformation at Kalabsh fault, Aswan, Egypt from Magnetic, GPS, and Seismic data, NRIAG, J Geophys, special issue, pp 681–700Google Scholar
  34. Mori J, Frankel A (1990) Source parameters for small event associated with the 1986 North Palm Springs, California, earthquake determined using empirical Green’s functions. Bull Seism Soc Am 80:270–295Google Scholar
  35. Scherbaum F, Johnson J (1992) Programmable Interactive Toolbox for Seismological Analysis (PITSA)Google Scholar
  36. Simpson D, Kebeasy R, Maamoun M, Ibrahim E, Megahed A (1986) Induced seismicity around Aswan Lake (Abst.). Tectonophys 118(3–4):28–30Google Scholar
  37. Simpson DW, Gharib AA, Kebeasy RM (1990) Induced seismicity and changes in water level at Aswan reservoir, Egypt. Gerlands Beitr Geophys Leipzig 99:191–204Google Scholar
  38. Suetsugu D (1998) Practice on source mechanism, IISEE Lecture note, 104 pp Tsukuba, JapanGoogle Scholar
  39. Sykes L (1978) Intraplate seismicity, reactivation of preexisting zones of weakness, alkaline magmatism and other tectonism postdating continental fragmentation. Rev Geophys Space Phys 16:621–688CrossRefGoogle Scholar
  40. Taha yS (1997) Evaluation of the crustal structure setting of Aswan area, Ph.D. thesis, Faculty of Science, Cairo University, Egypt, 152 pGoogle Scholar
  41. Talwani P, Rajendran K (1991) Some seismological and geometric features of intraplate plate earthquakes. Tectonophys 186:19–41CrossRefGoogle Scholar
  42. Tealeb A (1999) proposed programs for monitoring crustal deformations at seismo active area of Aswan, Egypt using geodetic techniques. Internal Report at NRIAG, 81pGoogle Scholar
  43. Woodward-Clyde Consultants (1985) Earthquake activity and stability evaluation for Aswan High Dam; Unpublished report, High and Aswan Dam Authority. Ministry of Irrigation, EgyptGoogle Scholar
  44. Xie J, Liu Z, Hermann R, Granswick E (1991) Source process of three aftershocks of the 1983 Goodnow, New York, earthquake; high resolution images of small symmetric rupture. Bull Seism Soc Am 81:818–843Google Scholar

Copyright information

© Saudi Society for Geosciences 2013

Authors and Affiliations

  1. 1.Seismology DepartmentNational Research Institute of Astronomy and Geophysics (NRIAG)HelwanEgypt

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