Advertisement

Arabian Journal of Geosciences

, Volume 5, Issue 4, pp 599–606 | Cite as

Focal mechanism of Badr earthquake, Saudia Arabia of August 27, 2009

  • Khalid S. Aldamegh
  • Hesham Hussein Moussa
  • S. Nasser Al-Arifi
  • Sayed S. R. Moustafa
  • Moustafa Hemeda Moustafa
Original Paper

Abstract

Focal mechanism solution of the 27th August 2009 earthquake (mb = 4.0) that occurred in the Badr area, northwest of Saudi Arabia, approximately 50 km from the Red Sea has been determined from the P-wave first motion polarities. Results show normal faulting mechanism with a negligible component of strike-slip motion with NE T-axis direction. This type of mechanism is common with other earthquakes of the northwestern Saudi Arabia and is considered to present the tectonic movement of the region. The dominantly extensional tectonic regime in this province demonstrates the influence of NE extension in the Red Sea. The strikes of the solution are consistent with those of the main faults near the epicenter. Hypocentral location of this earthquake was carried out using the data from the King Abdulaziz City of Science and Technology Seismic Network, Saudi Arabia, and the Egyptian National Seismological Network, Egypt. The horizontal and vertical confidence estimates are 0.5 km for both. The local magnitude, M L, following the Richter’s original definition was also derived from ten digital three-component broadband seismograms. The average local magnitude determined in this study is 3.8 ± 0.17. The estimated seismic moment of this event is \( {3}.{\hbox{7e}} + {14}\,{\hbox{Nm}}\left( {{M_{\rm{W}}} = {3}.{66}\pm 0.0{7}} \right) \).

Keywords

Focal mechanism Badr earthquake Moment magnitude Seismotectonics 

دراسة ميكانيكية البؤرة لزلزال 27 أغسطس 2009 بمنطقة بدر بالمملكة العربية السعودية

الملخص العربى

تم تحديد ميكانيكة البؤرة لزلزال 27 أغسطس 2009 الذى وقع في منطقة بدر ، الى الشمال الغربي من المملكة العربية السعودية ، حوالي 50 كيلومترا من البحر الأحمر والذى بلغت قوته المحسوبة من الموجات الأولية ٤ وذلك بإستخدام اتجاه الحركة في بداية وصول الموجات الزلزالية الأولية.وتشير النتائج إلى حدوث فالق عادى بالإضافة إلى مركبة ضئيلة من الحركة الإزاحية يأخذ نفس إتجاه الفوالق الرئيسية القريبة من البؤرة الزلزالية وبمحور شد يأخذ إتجاه شمال شرق. وتتفق هذه الميكانيكية مع الميكانيكية العامة لزلازل شمال غرب المملكة العربية السعودية. كما يتفق الإتجاه السائد لمحور الشد مع اتجاه حركة الإنفراج في البحر الأحمر. وقد تم تحديد موقع هذا الزلزال باستخدام بيانات الشبكة الزلزالية لمدينة الملك عبدالعزيز للعلوم والتقنية بالمملكة العربية السعودية و الشبكة المصرية الوطنية لرصد الزلازل بمصربدقة تصل الى نصف كيلو متر لكل من المسافة الافقية والعمق.وقد تم ايضا حساب القدرالزلزالى من عشر تسجيلات زلزالية رقمية واسعة النطاق ذات المركبات الثلاثه باستخدام التعريف الاصلى لريختر. وقد بلغت متوسط القدرة المحلية المحددة في هذه الدراسة 3.8 ± 0.17. و يقدر العزم الزلزالى المحسوب لهذا الحدث بحوالى 3.7 1410x نيوتن متر وهو مايساوى قدرا زلزاليا 3.66 ± 0.07.

References

  1. Agar RA (1987) The Najd fault system revisited; a two-way strike-slip orogen in the Saudi Arabian shield. J Struct Geol 9:41–48CrossRefGoogle Scholar
  2. Aldamegh KS, Abou Elenean KM, Hussein HM, Rodgers AJ (2009) Earthquake sequence, Eastern Red Sea margin, Kingdom of Saudi Arabia. J Seismol. doi: 10.1007/s10950-008-9148-5 Google Scholar
  3. Ambraseys NN, Melville CP, Adams RD (1994) The seismicity of Egypt, Arabia and the Red Sea: a historical review. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  4. Beydoun ZR (1994) Arabian plate oil and gas: why so rich and so prolific? Episodes 21(2):74–81Google Scholar
  5. Camp VE (1984) Island arcs and their role in the evolution of the western Arabian Shield. Geol Soc Am Bull 95:913–921CrossRefGoogle Scholar
  6. Camp VE, Hooper PR, Roobol MJ, White DL (1987) The Madinah historical eruption, Saudi Arabia: magma mixing and simultaneous extrusion of three basaltic chemical types. Bull Volcanol 49:489–508CrossRefGoogle Scholar
  7. Delfour J (1983) Geology and mineral resources of the northern Arabian Shield. Saudi Arabian Deputy Minist. Miner. Resour. OpenFile Rep. BRGMOF0230Google Scholar
  8. Ebel John E (1982) M L measurements for northeastern United States earthquakes. Bull Seismol Soc Am 72(4):1367–1378Google Scholar
  9. Eyal Y, Reches Z (1983) Tectonic analysis of the Dead Sea Rift region since the late-Cretaceous based on mesostructures. Tectonics 2:167–185CrossRefGoogle Scholar
  10. Husseini MI (1988) The Arabian infracambrian extensional system. Tectonophysics 148(1–2):93–103CrossRefGoogle Scholar
  11. Johnson PR (1983) A preliminary lithofacies map of the Arabian Shield. Deputy Ministry of Mineral Resources, Jeddah, Saudi Arabia, Rechnical Record RF-TR-03-2, p 72Google Scholar
  12. Klein RW (1987) Hypocenter location program. HYPOINVERSE, part 1:user guide, open file report. US Geological Survey, Menlo Park, p 113Google Scholar
  13. McClusky S, Reilinger R, Mahmoud S, Ben Sari D, Tealeb A (2003) GPS constraints on Africa (Nubia) and Arabia plate motions. Geophys J Int 155:126–138CrossRefGoogle Scholar
  14. Nuttli OW (1973) Seiamic wave attenuation and magnitude relations for eastern North America. J Geophys Res 78:876–885CrossRefGoogle Scholar
  15. Quennell AM (1958) The structural and geomorphic evolution of the Dead Sea Rift. Q J Geol Soc Lond 114:1–24CrossRefGoogle Scholar
  16. Quennell AM (1984) The western Arabian rift system. In J.E. Dixon and A.R.F.Robertson eds, the Geological Evolution of the eastern Mediterranean. Geological Society Special Publication 17:775–788Google Scholar
  17. Reilinger R, McClusky S, Vernant P, Lawrence S, Ergintav S, Cakmak R, Ozener H, Kadirov F, Guliev I, Stepanyan R, Nadariya M, Hahubia G, Mahmoud S, Sakr K, ArRajehi A, Paradissis D, Al-Aydrus A, Prilepin M, Guseva T, Evren E, Dmitrotsa A, Filikov SV, Gomez F, Al-Ghazzi R, Karam G (2006) GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions. Journal of geophysical research 111:1–26. doi: 10.1029/2005JB004051, B05411CrossRefGoogle Scholar
  18. Richter CF (1958) Elementary seismology. W. H. Freeman, San Francisco, p 758Google Scholar
  19. Richter CF (1935) An instrumental earthquake magnitude scale. Bull Seismol Soc Am 25:1–32Google Scholar
  20. Rodgers A, Walter WR, Mellors RJ, Abdullah MS, Al-Amri, Zhang Y-S (1999) Lithospheric structure of the Arabian shield and platform from complete regional waveform modelling and surface wave group velocities. Geophys J Int 138:871–878CrossRefGoogle Scholar
  21. Roobol J (2007) Cenozoic faults in Western Saudi Arabia. In: 7th meeting of the Saudi society for geosciences, King Saud University, Riyadh, Saudi ArabiaGoogle Scholar
  22. Sandvol Eric A, Bao Xueyang, Ekrem Zor, Jiakang Xie, Brian J, Mitchell, David P. Schaff (2007) Lg and pg attenuation in the middle east. 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, 266–273Google Scholar
  23. Snoke A (2003) Focal mechanism determination software (FOCMEC package), http://www.geol.vt.edu/outreach/vtso/focmec
  24. Stern R (1985) The Najd fault system, Saudi Arabia and Egypt: a late Precambrian rift-related transform system? Tectonics 4(5):497–511CrossRefGoogle Scholar
  25. Stern RJ (1994) Arc assembly and continental collision in the Neoproterozoic East African orogen: implications for the consolidation of Gondwanaland. Annual Review of Earth and Planetary. Science 22:319–351Google Scholar
  26. Stoeser DB (1986) Distribution and tectonic setting of plutonic rocks of the Arabian Shield. J Afr Earth Sci 4:21–46Google Scholar
  27. Stoeser DB, Fleck RJ, Stacey JS (1984) Geochronology and origin of early tonalite gneiss of the WADI Tarib batholith and the formation of syn-tectonic gneiss complexes in the southeast Arabian Shield. Faculty Earth Science Bulletin, King Abdulaziz University, Jeddah 6,351–364Google Scholar
  28. Street RL, Herrmann RB, Nuttli OW (1975) Spectral characteristics of the Lg-wave generated by the central United States earthquakes. Geophys J R Astron Soc 41:51–63CrossRefGoogle Scholar
  29. Vail JR (1983) Pan-African crustal accretion in northeast Africa. J Afr Earth Sci 1:285–294Google Scholar

Copyright information

© Saudi Society for Geosciences 2010

Authors and Affiliations

  • Khalid S. Aldamegh
    • 1
  • Hesham Hussein Moussa
    • 2
    • 3
    • 4
  • S. Nasser Al-Arifi
    • 3
    • 5
  • Sayed S. R. Moustafa
    • 2
    • 3
  • Moustafa Hemeda Moustafa
    • 1
  1. 1.Astronomy and Geophysics Research InstituteKing Abdulaziz City for Science and Technology (KACST)RiyadhSaudi Arabia
  2. 2.Seismology DepartmentNational Research Institute of Astronomy and GeophysicsHelwanEgypt
  3. 3.Community CollegeShaqra UniversityAlquwayiyahSaudi Arabia
  4. 4.North Africa Seismological Group NASG Net40/OEA/ICTPTriesteItaly
  5. 5.Geology Department, Faculty of ScienceKing Saud UniversityRiyadSaudi Arabia

Personalised recommendations