Estimation of frequency-dependent coda wave attenuation structure at the vicinity of Cairo Metropolitan area

Estimation of seismic wave attenuation in the shallow crust in terms of coda wave Q structure previously investigated (Sayed et al. 2002) in the vicinity of Cairo Metropolitan area was improved using seismograms of local earthquakes  recorded by the Egyptian National Seismic Network (ENSN). The seismic wave attenuation was measured in the study area from the time decay of coda wave amplitudes on narrow bandpass filtered seismograms on the basis of the single scattering theory. The frequency bands of interest are from 1.5 Hz to 18 Hz. In general, the values obtained for paths and events foci and El-Fayoum (FYM) and Wadi Hagul Sations (HAG) are very similar for all frequency bands. A regional attenuation law Qc = 85.66 f0.79 was obtained