Isaac Scientific Publishing

Geosciences Research

Source Characterizations of Small Earthquakes

Download PDF (2400.5 KB) PP. 138 - 150 Pub. Date: May 15, 2017

DOI: 10.22606/gr.2017.22007


  • Ahmed Badawy*
    Seismology Dept., National Research Institute of Astronomy and Geophysics, 11421-Helwan, Egypt
  • Sh. Ali

    Seismology Dept., National Research Institute of Astronomy and Geophysics, 11421-Helwan, Egypt
  • A. El-Werr

    Geophysics Dept., Faculty of Sciences, Ain Shams University, Cairo, Egypt


The source characterizations of five small felt earthquakes have been investigated using local seismograms of the Egyptian National Seismological Network (ENSN), Egypt. The studied earthquakes are located at three inland dislocations namely: Dahshour, southeast Beni-Suef and Cairo-Suez district. Throughout the analysis, Empirical Green’s Function (EGF) deconvolution technique has been applied. The records of an appropriate aftershock are taken as the EGF and are used to deconvolve the mainshock seismograms, thus obtaining a Relative Source Time Function (RSTF) at each station. The deconvolution is performed using P waves in frequency domain. From the time-domain analysis of the RSTF, the resulting source time functions indicate a complex rupture process for the strike-slip events (11 October, 1999 and 08 November, 2006)) and simple rupture process for the dip-slip events (28 December, 1999; 12 June 2001 and 17 December, 2001). The azimuthally dependencies of the RSTF pulse amplitudes and widths are used to estimate rupture velocity and rupture directivity. We found that the rupture directions are tending to propagate toward the north and NNW.


Source characterization, small inland earthquakes, Empirical Green’s Function, relative source time function, tectonic implications.


[1] A. K. Abdel-Fattah. Source characteristics of the 28th January 1999 Nagano earthquake, Japan. IISEE, Vol.35: 45-57, 1999.

[2] K. M. Abou Elenean Focal mechanisms of small and moderate size earthquakes recorded by the Egyptian National Seismic Network (ENSN), Egypt, NRIAG. J Geophys 6(1):119–153, 2007 .

[3] K. Aki,: Scaling law of seismic spectrum, J. Geophys. Res., vol. 72, p. 1217–1231, 1967.

[4] C. J. Ammon,,: A comparison of deconvolution techniques, Lawrence Livermore National Laboratory Report, UCID-ID-111667, p. 1-43, 1992 .

[5] C. L. Ammon, , A. A. Velasco, and T. Lay,: Rapid estimation of rupture directivity: Application to the 1992 Landers (Ms=7.4) and Cape Mendocino (Ms = 7.2) California Earthquakes, Geophys. Res. Lett., vol. 20, p. 97-100, 1993 .

[6] A. Badawy: Source parameters and tectonic implications of recent Sinai (Egypt) earthquakes. Acta Geod. Geoph. Hung., 30: 349-361, 1995.

[7] A. Badawy, Seismicity and kinematic evolution of the Sinai plate. Ph D thesis, pp115, L. E?tv?s Univ. Budapest, 1996.

[8] A. Badawy: Historical seismicity of Egypt. Acta Geod. Geoph. Hung., 34 (1-2): 119- 135, 1999.

[9] A. Badawy: Status of the crustal stress as inferred from earthquake focal mechanisms and borehole breakout in Egypt. Tectonophysics, 343 (1-2): 49-61, 2001a.

[10] A. Badawy: The present-day stress field in Egypt. Annali Di Geofisica 44 (3): 557- 570, 2001b .

[11] A. Badawy: Seismicity of Egypt. Seismolo. Res. Lett. 76 (2) 149-160, (2005a.

[12] A. Badawy: Present-day seismicity, stress field and crustal deformation of Egypt. Journal of Seismology, 9 (3):267-276, 2005b.

[13] A. Badawy and A. K. Abdel-Fattah: Source parameters and fault plane determinations of the 28 December, 1999 northeastern Cairo earthquakes. Tectonophysics, 343:63-77, 2001.

[14] A. Badawy and A. K. Abdel-Fattah: Analysis of the southeast Beni-Suef, northern Egypt Earthquake sequence. J. Geodynamics. 33 (3): 219-234, 2002.

[15] A. Badawy and P. Mónus : Dynamic source parameters of the 12th October, 1992 earthquake, Cairo, Egypt. J. Geodynamics, 20: 99-109, 1995.

[16] A. Badawy and F. Horváth: Seismicity of the Sinai subplate region: Kinematic implications. J. Geodynamics, 27: 451-468, 1999a .

[17] A. Badawy and F. Horváth: Sinai subplate and kinematic evolution of the northern Red Sea. J. Geodynamics, 27: 433-450, 1999b .

[18] A. Badawy, S. M. Abdel-Monem, K. Sakr, and N. Abo-Ali,: Seismicity and kinematic evolution of the middle Egypt. J. Geodynamics 42: 28-37, 2006.

[19] A. Badawy, A. K. Abdel-Fattah, Sh. M. Ali, and W. Farid,: Source parameters of the ML 4.1 earthquake of November 08, 2006, southeast Beni-Suef, northern Egypt, Journal of African Earth Sciences, vol. 51, p. 151-159, 2008.

[20] A. Badawy, A., Al-werr, and Sh. M. Ali., Relative location and source mechanism of inland earthquakes in northern Egypt. J. Seismology Doi10.1007/s10950-01-13-9387-z, 2014 .

[21] M. Bertero, D. Bindi, P. Boccacci, M. Cattaneo, C. Eva, and V. Lanza,: Application of the projected Landweber method to the estimation of the source time function in seismology, Inverse Problems, vol.13, p. 465–486, 1997.

[22] J. Boatwright: A spectral theory for circular seismic sources: simple estimates of source dimension, dynamic stress drop and radiated energy. Bull. Seism. Soc. Am., 70: 1-28, 1980.

[23] J. Brune, : Tectonic stress and the spectra of seismic shear waves from earthquakes. J. Geophys. Res., 75: 4997-5009, 1970.

[24] J. Brune,: Correction. J. Geophys. Res., 76: 5002, 1971.

[25] F. Courboulex, J. Virieux, A. Deschamps, D. Gibert, and A. Zollo, : Source investigation of a small event using empirical Green’s functions and simulated annealing, Geophys. J. Int., vol. 125, p. 768–780, 1996.

[26] M. DiBona, and J. Boatwright: Single-station decomposition of seismograms for subevent time history. Geophy. J. Inter., 105: 103-117, 1989.

[27] W. L. Ellsworth, and G. C. Beroza: Seismic evidence for an earthquake nucleation phase. Science, 268: 851-855, 1995.

[28] A. Frankel, J. Fletcher, F. Vernon; L. Haar; J. Berge; T. Hanks and J. Brune: Rupture characteristics and tomographic imaging of ML=3 earthquakes near Azna southern California, J. Geophys. Res., 91: 12633-12650, 1986.

[29] E. Fukuyama and K. Irikura, : Rupture process of the 1983 Japan Sea (Akita-Oki) earthquake using a waveform inversion method, Bull. Seism. Soc. Am., vol. 76, p. 1623– 1640, 1986.

[30] D. M. Hadley, and D. V. Helmberger : Simulation of strong ground motion. Bull. Seism. Soc. Am., 70: 617-630, 1980.

[31] S. H. Hartzell,: Earthquake aftershocks as Green’s functions. Geophys. Res Lett., 5: 1- 4, 1978.

[32] S. H. Hartzell and T. H. Heaton: Teleseismic time functions for large, shallow subduction zone earthquakes, Bull. Seism. Soc. Am., vol. 75, p. 965-1004, 1985 .

[33] H. Houston: Influence of depth, focal mechanism and tectonic setting on the shape and duration of earthquake source time functions. J. Geophys. Res., 106:11137-11150, 2001.

[34] P. F. Ihmle: Frequency dependent relocation of the 1992 Nicaragua slow earthquake: an empirical Green’s function approach, Geophys. J. Int., vol.127, p. 75–85, 1996.

[35] K. Irikura, and I. Muramatu: Synthesis of strong ground motions during large earthquakes. Bull. Disaster. Prev. Res. Inst., Kyoto Univ., 33: 63-104, 1982.

[36] H. Kanamori,. A semi-empirical approach to prediction of long-period ground motions from great earthquakes. Bull. Seism. Soc. Am., 69: 1645-1670, 1979.

[37] C. L. Lawson, and R. J. Hanson:. Solving Least Squares Problems, Prentics-Hall, Inc., New Jersey. 1974.

[38] Y. Li, and C. H. Thurber: Source properties of two microearthquakes in Kilauea volcano, Hawaii, Bull. Seism. Soc. Am., 78: 1123-1132, 1988 .

[39] Y. Li, C. Doll and M. N. Toksoz: 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: 1604-1621, 1995.

[40] J. Mori, Fault plane determinations for three small earthquakes along San Jacinto fault California: search for cross faults. J. Geophy. Res., 98: 17711-17722, 1993.

[41] J. Mori and A. Frankel : Source parameters for small events associated with the 1986 North Palm Springs, California, earthquake determined using empirical Green’s functions. Bull. Seism. Soc. Am., 80: 278-295, 1990.

[42] C. Mueller: Source pulse enhancement by deconvlution of an empirical Green’s function. Geophys. Res. Lett., 12: 33-36, 1985.

[43] R. Said, : The geology of Egypt. Elsevier, Amsterdam, the Netherlands, 1962.

[44] J. C. Savage and H. S. Hasegawa: Some properties of tensile inferred from elastic wave radiation. J. Geophys. Res., 69: 2091-2106, 1964.

[45] N. Shukri: The geology of the desert east of Cairo, Bull. Inst. Desert, Egypt, 3(2): 89-105, 1952.

[46] S. A. Sipkin, and A. L. Lerner-Lam: Pulse-shape distortion introduced by broadband deconvolution, Bull. Seism. Soc. Am., vol. 82, p. 238-258, 1992.

[47] M. Valle: Stabilizing the empirical Green function analysis: development of the projected Landweber method, Bull. Seism. Soc. Am., vol. 94, p. 394–409, 2004.

[48] A. A. Velasco, C. J. Ammon, and T. Lay,: Empirical Green function deconvolution of broadband surface waves: rupture directivity of the 1992 Landers, California (Mw_7.3), Bull. Seism. Soc. Am., vol. 84, p. 735–750, 1994.

[49] F. Wu and H. Kanamori: Source mechanism of the February 4, 1965 Rate Island earthquake. J. Geophys. Res., 78: 6082-6092, 1973.

[50] J. Xie, Z. Liu; R. Herrmann and E. Cranswick: Source processes of three aftershocks of the 1983 Goodnow, New York, earthquake: high resolution images of small symmetric rupture. Bull. Seism. Soc. Am., 81: 818-843, 1991.