f Q-values For P And S Waves In South Sinai And South Gulf Of Suez Region, Egypt

The quality factor Q has been estimated using spectral amplitudes of P and S waves from earthquakes recorded by the seismic network of Egyptian National Seismological Network (ENSN) in south Sinai and north Red Sea region. The earthquakes recorded at nine stations – DHA, NUB, TR1, TR2, KAT, SH2, GRB, HRG and SFG have been used. The spectral amplitude ratios have been calculated between 2 - 20 Hz and single station spectral ratio method has been applied for this purpose. The results show that the quality factors for both P and S waves (Qp and Qs) increase as a function of frequency according to law Q = Q0fn. By averaging the Q- Value obtained at all stations we calculated the average attenuation laws: Qp = (13.15± 0.76) f0.95± 0.19 and Qs = (20.05± 0.79) f1.03±0.04 for P and S waves respectively. The QS /QP ratio for KAT station at lower frequencies is less than 1, whereas at HRG and SH2 stations QS /QP ratio is are greater than 1. These relations are useful for the estimation of source parameters of earthquakes and simulation of earthquake strong ground motions.