Estimate of seismic p-wave attenuation in central Saudi Arabia

Abstract EN

TWO least-squares attenuation estimation methods have been applied on the Pg crustal phase extracted from the seismic deep-refraction profile in central Saudi Arabia.

These methods include the spectral ratio method and pulse broadening technique.

The spectral ratio method proves to be unstable on signals with relatively low SIN ratio.

However, the pulse broadening technique yielded fairly good results, since it measures the frequency absorption of the seismic signal rather than amplitude variations.

In both cases, the estimated Q values were based on constant-^ model over a specific frequency range of interest.

l or large SIN ratio, the computed attenuation (Q) from the spectral ratio method compares very favorably with that determined from the pulse broadening technique.

Our preliminary re- sults show that Qp estimated from the spectral ratio method increases with the difference in source-receiver distance between two stations.

This increase implies Qp depth-dependent near shot point 1 of the refraction profile.

The estimated Q values are of significant importance for regional and global tectonic investigations and seismic hazard assessment in the Arabian plate.