S-WAVE ATTENUATION AND SPECTRAL DECAY PARAMETER FOR THE AVAJ REGION, IRAN*

Abstract

The strong ground motions recorded during the 2002 Avaj earthquake have been used to estimateS wave attenuation, Qβ, and spectral decay parameter, κ, for the Avaj region. Qβ for shear wave is estimatedas a function of frequency in the range of 0.6- 18 Hz. The results show that Qβ increases with frequency in theform of Qβ=62.7 f 0.9. Our estimates are within the estimated range for different parts of the world for Qo andn. The spectral decay parameter, κ, has been estimated from the high frequency of the spectra. Thedependence of κ on the epicenteral distance for the Avaj region is also found.