Estimation of Shear Wave Attenuation for Bam Earthquake, Strong Motion Records, Using Singular Value Decomposition

Strong motion records from the 2002 Bam Earthquake are used to investigate the shape of attenuation function in several frequencies ranging between 0.8 to 18 Hz. Amplitude spectra of the records are inverted to find source scaling factor and attenuation parameters using Singular Value Decomposition method (SVD). After correcting the obtained attenuation functions for geometrical spreading effect, the values of Qβ follow the frequency dependent relation, =Qβ 0/195ƒ, which is in good agreement with similar results in other tectonically active regions in the world and could be served as a basic input parameter for future seismic hazard studies in the region of bam.