Source characteristics and tectonic implications of moderate earthquake, northeastern Cairo Prefecture

• Autorzy: Abdel-Fattah A.K. , Badawy A.
• Języki publikacji: EN

Abstrakty

EN

Using local seismograms of the Egyptian National Seismological Network (ENSN), source characteristics of a moderate earthquake Mw = 4.5 (28 December 1999) are analyzed. In this analysis, the Empirical Green's Function (EGF) deconvolution technique is 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 simple rupture process. The azimuthal dependencies of the RSTF pulse amplitudes and widths are used to estimate rupture velocity and rupture direction for the mainshock. The azimuth of rup-ture direction is obtained using a global optimization method. We found that the rupture direction of the main event propagated toward S175 E with an averaged rupture velocity around 0.75 Vs. The result obtained for rupture direction is in agreement with one of the nodal planes of focal mechanism. From the rupture directivity analysis, focal mechanism and geological evidence it follows that the investi-gated event reflects a reactivation of a NW-SE Oligocene deep-seated normal faulting with sinistral movement. Source parameters were estimated using RSTFs of the mainshock, including seismic moment of 2.85×1015 Nm, fault radius of 344 m, fault length 1460 m, and static stress drop of 3.071 MPa.

Słowa kluczowe

EN

empirical Green's function; relative source time function; source parameters; tectonic implications

• Wydawca: Instytut Geofizyki PAN
• Czasopismo: Acta Geophysica Polonica
• Rocznik: 2004
• Tom: Vol. 52, nr 1
• Strony: 29--43
• Opis fizyczny: Bibliogr. 35 poz.

Twórcy

autor

Abdel-Fattah A.K.

• National Research Institute of Astronomy and Geophysics, 11421-Helwan, Cairo, Egypt

autor

Badawy A.

• National Research Institute of Astronomy and Geophysics, 11421-Helwan, Cairo, Egypt

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