Journal of Seismology

, Volume 11, Issue 3, pp 259–274 | Cite as

Source mechanism and source parameters of May 28, 1998 earthquake, Egypt

  • K. M. Abou Elenean
  • H. M. HusseinEmail author
Original Article


On May 28, 1998, a moderate size earthquake of mb 5.5 occurred offshore the northwestern part of Egypt (latitude 31.45°N and longitude 27.64°E). It was widely felt in the northern part of Egypt. Being the largest well-recorded event in the area for which seismic data from the global digital network are available, it provides an excellent opportunity to study the tectonic process and present day stress field occurring along the offshore Egyptian coast. The source parameters of this event are determined using three different techniques: modeling of surface wave spectral amplitudes, regional waveform inversion, and teleseismic body waveform inversion. The results show a high-angle reverse fault mechanism generally trending NNW–SSE. The P-axis trends ENE–WSW consistently with the prevailed compression stress along the southeastern Hellenic arc and southwestern part of the Cyprean arc. This unexpected mechanism is most probably related to a positive inversion of the NW trending offshore normal faults and confirms an extension of the back thrusting effects towards the African margin. The estimated focal depth ranges from 22 to 25 km, indicating a lower crustal origin earthquake owing to deep-seated tectonics. The source time function indicates a single source with rise time and total rupture duration of 2 and 5 s, respectively. The seismic moment (M o) and the moment magnitude (M w) determined by the three techniques are 1.03 × 1017 Nm, 5.28; 1.24 × 1017 Nm, 5.33; and 1.68 × 1017 Nm, 5.42; respectively. The calculated fault radius, stress drop, and the average dislocation assuming a circular fault model are 7.2 km, 0.63 Mpa, and 0.11 m, respectively.


Source mechanism Source parameter Surface wave amplitude spectra Waveform inversion 28 May 1998 earthquake Continental margin of Egypt 


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  1. Abdel Aal A, Price RJ, Vaitl DJ, Shrallow A (1994) Tectonic evolution of the Nile Delta, its impact on sedimentation and hydrocarbon. Proceedings of the Twelfth Petroleum Exploration and Production Conference, November 1994, pp 19–34Google Scholar
  2. Abou Elenean K (1993) Seismotectonics of the Mediterranean region north of Egypt and Libya, M. Sc. thesis, Faculty of Science, Mansoura University, EgyptGoogle Scholar
  3. Abou Elenean KM (1997) Seismotectonics of Egypt in relation to the Mediterranean and Red Seas tectonics. Ph. D. thesis, Fac. Sc. Ain Shams Univ., pp 200Google Scholar
  4. Abou Elenean K (2006) Focal mechanisms of small and moderate earthquakes recorded by the Egyptian National Seismic Network (ENSN), Egypt, unpublished workGoogle Scholar
  5. Aki K (1996) Generation and propagation of G waves from the Niigata earthquake of June 16, 1964. Part 2. Estimation of earthquake moment, release of energy, and stress-strain drop from G wave spectrum. Bull Earthq Res Inst Tokyo Univ 44:73–88.Google Scholar
  6. Arvidsson R, Ben-Avraham Z, Ekström G, Wdowinski S (1998) Plate tectonic framework for October 9, 1996, Cyprus earthquake. Geophys Res Lett 25:2241–2244CrossRefGoogle Scholar
  7. Ben-Avraham Z, Nur A (1986) Collisional processes in the Eastern Mediterranean. Geol Rundsch 75(1):209–217CrossRefGoogle Scholar
  8. Brönner M, Makris J (2000) Crustal structure of the Libyan margin. In: Proceedings of African continental margins of the Mediterranean Sea, Djerba, 22–25 November 2000. CISEM Workshop Series no. 13, pages 63–66Google Scholar
  9. Christova CV, Nikolova S (1994) Stress field in the Hellenic Wadati-Beniff zone. ESC, XXIV General Assembly 1994, Sept, 19–24, Athens, Greece. Proceeding and Activity Report, pp 387–393Google Scholar
  10. Doglioni C, Agostini S, Crespi M, Innocenti F, Manetti P, Riguzzi F, Savascin Y (2002) On the extension in western Anatolia and the Aegean Sea. Journal of Virtual Explorer 7:117–131Google Scholar
  11. Ebel JE, Burdick LJ, Stewart GS (1978) The source mechanism of the August 7, 1996 El Golfo earthquake. Bull Seismol Soc Am 68:1281–1292Google Scholar
  12. Egyptian Geological Survey and Mining Authority, EGSMA (1981) Geologic map of Egypt 1:2000000Google Scholar
  13. Futterman W (1962) Dispersive Body waves. J Geophys Res 67:5279–5291Google Scholar
  14. Guiraud R, Bosworth W (1999) Phanerozoic geodynamic evolution of the northeastern Africa and the Northwestern Arabian Platform. Tectonophysics 315:73–108CrossRefGoogle Scholar
  15. Hanks TC, McGuire RK (1981) The character of high frequency strong ground motion. Bull Seis Soc Am 71:2071–2095Google Scholar
  16. Hassoup A, Tealeb A (2000) Attenuation of intensity in the northern part of Egypt associated with May 28, 1998 Mediterranean earthquake. Acta Geophys Pol 48:79–92Google Scholar
  17. Herrmann R, Ammon C (2004) Computer programs in seismology (CPS), Source inversion,
  18. Ichinose G, Yuehua Z (2000) Waveform modeling and moment tensor inversion tools,
  19. Ichinose G, Anderson J, Smith K, Yuehua Z (2003). Source parameters of Eastern California and Western Nevada Earthquake from regional moment tensor inversion. Bull Seism Soc Am 93:61–84CrossRefGoogle Scholar
  20. Jackson J, McKenize D (1984) Active tectonics in the Alpine–Himalayan belt between western Turkey and Pakistan. Geophys J R Astron Soc 77:185–246Google Scholar
  21. Kahle H-G, Straub C, Reilinger R, McClusky S, King R, Hurst K, Veis G, Kastens K, Cross P (1998) The strain field in the eastern Mediterranean region, estimated by repeated GPS measurments. Tectonophysics 294:237–252CrossRefGoogle Scholar
  22. Kanamori H, Anderson DL (1975) Theoretical basis of some empirical relations in seismology. Bull Seismol Soc Am 65:1073–1095Google Scholar
  23. Kasahara K (1985) Earthquake mechanism. Cambridge University Press, 248 pagesGoogle Scholar
  24. Kikuchi M, Kanamori H (1991) Inversion of complex body waves, III. Bull Seism Soc Am 81:2335–2350Google Scholar
  25. Kikuchi M, Ishida M (1993) Source retrieval for deep earthquakes with broadband records. Bull Seism Soc Am 83:1855–1870Google Scholar
  26. Le Pichon X, Augustithis S, Mascle J (1982) Geodynamics of the Hellenic arc and trench. Tectonophysics 86:1–304CrossRefGoogle Scholar
  27. Loncke L, Gaullier V, Bellaiche G, Mascle J (2000) Recent depositional pattern of the Nile deep-sea fan from echo-character mapping: interaction between turbidity currents, mass-wasting process and tectonics. Proceedings of African continental margins of the Mediterranean Sea, Djerba, 22–25 November 2000. CISEM Workshop Series no. 13, pages 71–75Google Scholar
  28. Lundgren PR, Emile A, Stein S (1988) Body wave deconvolution for variable source parameters; application for the 1987 December 6 Kuriles earthquake. Geophys J 94:171–180Google Scholar
  29. Makris J (1976) A dynamic model of the Hellenic Arc deduced from geophysical data. Tectonophysics 36:339–346CrossRefGoogle Scholar
  30. Makris J, Stobbe C (1984) Physical properties and state of the crust and upper mantle of the Eastern Mediterranean Sea deduced from geophysical data. Mar. Geol 55:347–363CrossRefGoogle Scholar
  31. Makris J, Stofen B, Vees R, Allam A, Maamoun M, Shehata W (1979) Deep seismic sounding in Egypt. Part I: The Mediterranean Sea between Crete- Sidi Barani and the coastal area of Egypt. Unpublished report, National Research Institute of Astronomy and Geophysics, Helwan, EgyptGoogle Scholar
  32. Maamoun M (1976) La seismicite du moyen et du Proche-orient dans le carde de la seismotectonique modiale. These de D. es Sc. Un. Louis Pasteur, Strasbourg, FranceGoogle Scholar
  33. Mancilla P (2001) Surface wave dispersion about the New Madrid Region, M. Sc. Thesis, Faculty of the Graduate School of Saint Louis University, USAGoogle Scholar
  34. Mart Y, Roberston AHF (1998) Eratosthenes Seamount: An oceanographic yardstick recording the Mesozoic-Tertiary geological history at the Eastern Mediterranean Sea. In: Robertson AHF, Emeis K-C, Richter C, Camerlenghi A (eds) Proc ODP, Sci. Results, 160:701–708. College Station, TX (Ocean Drilling Program)Google Scholar
  35. McClusky S, Balassanian S, Barka A, Demir C, Ergintav S, Georgiev I, Gurkan O, Hamburger M, Hurst K, Kahle H, Kastens K, Kekeliduze G, King R, Kotzev V, Lenk O, Mahmoud S, Mishin A, Nadariya M, Ouzounis A, Paradissis D, Peter Y, Prilepin M, Rilinger R, Sanli I, Seeger H, Tealb A, Toksöz MN, Veis G (2000) GPS constraints on plate kinematics and dynamics in the eastern Mediterranean and Caucasus. J Geophys Res 105:5695–5719CrossRefGoogle Scholar
  36. McKenzie D (1972) Active tectonics in the Mediterranean Region. Geophys J R Astron Soc 30:109–185Google Scholar
  37. Mosconi A, Rebora A,Venturino G, Bocc P, Khalil M (1996) Egypt-Nile Delta and North Sinai Cenozoic tectonic evolutionary model: a proposal. Proceeding of the 13th Egypt General Petroleum Cooperation: Exploration and Production Conference, Cairo, Egypt, vol. I, pp 203–224Google Scholar
  38. Papadopoulos G, Knodopoulou D, Leventakis A, Pavlides S (1986) Seismotectonics of the Aegean region. Tectonophysics 124:67–84CrossRefGoogle Scholar
  39. Papazachos BC, Papadimitriou EE, Kiratzi AA, Papazachos CB, Louvari EK (1998) Fault plane solutions in the Aegean Sea and the surrounding area and their tectonic implications. Bollettino di Geofisica Teoretica ed Applicata 39:199–218Google Scholar
  40. Parke G (2001) Active tectonics and sedimentary processes in western Turkey. PhD thesis, University of CambridgeGoogle Scholar
  41. Pilidou S, Priestley K, Jackson J, Maggi A (2004) The 1996 Cyprus earthquake: a large, deep event in the Cyprean Arc. Geophys J Int 158:85–97CrossRefGoogle Scholar
  42. Riad S, Meyers H (1985) Earthquake catalog for the Middle East Countries 1900–1983. World Data Center for Solid Earth Geophysics, Rep. SE-40, National Oceanic and Atmospheric Administration (NOAA), US Dept. of Commerce, Boulder, Colorado, USAGoogle Scholar
  43. Ritsema J, Lay T (1995) Long period regional waves moment tensor inversion for earthquakes in the western United States. J Geophys Res 100:9853–9864CrossRefGoogle Scholar
  44. Robert S, Kerry Seih Y, Clarence RA (1997) The Geology of Earthquakes. Oxford University Press, New YorkGoogle Scholar
  45. Salamon A, Hofstetter A, Garfunkel Z, Ron H (1996) Sesimicity of the Eastern Mediterranean Region: perspective from the Sinai subplate. Tectonophysics 263:293–305CrossRefGoogle Scholar
  46. Sella GF, Dixon TH, Mao A (2002) Revel: A model for recent plate velocities from space geodesy. J Geophys Res 107(B4), doi: 1010.1029/2000JB000033
  47. Snoke A (2003) Focal mechanism determination software (FOCMEC package),
  48. Sofratome group (1984) El-Daba nuclear power plant, NPPA, Ministry of Electricity, Egypt. Unpublished reportGoogle Scholar
  49. Sonder L, England P (1989) Effects of a temperature-dependant rheology on large-scale continental extension. J Geophys Res 94:7603–7619CrossRefGoogle Scholar
  50. Taymaz T, Jackson J, Westaway R (1990) Earthquake mechanism in the Hellenic Trench near Crete. Geophys J Int 102:695-731CrossRefGoogle Scholar
  51. Zeng Y, Anderson J (1995) A method for direct computation of the differential seismogram with respect to the velocity change in a layered elastic solid. Bull Seismol Soc Am 85:300-307Google Scholar

Copyright information

© Springer Science+Business Media, Inc. 2007

Authors and Affiliations

  1. 1.Seismology DepartmentNational Research Institute of Astronomy and GeophysicsHelwanEgypt

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