پديد آورندگان :
Mahmoodi ، Hoda University of Tehran - Institute of Geophysics , Rahimi ، Habib University of Tehran - Institute of Geophysics , Maleki ، Behzad University of Tehran - Institute of Geophysics
كليدواژه :
Quality factor , Source Parameters , inversion method , Source spectrum
چكيده فارسي :
In this paper, the shear wave quality factor and source parameters in the near field are estimated by analyzing the acceleration data in Zagros region. Accelerograms recorded by Building and Houses Research Center strong ground motion network have been used. The data have been considered with the magnitude of 4.7 to 6.3 collected from 1999 to 2014. In this approach, the theoretical Swave displacement spectra conditioned by frequency independent Q was fitted with the observed displacement spectra. The source spectrum of an earthquake can be approximated by the omegasquare ω2 model, which has ω2 decay for frequencies higher than the corner frequency. By following the mentioned approach, corner frequency, scalar moment, moment magnitude and frequency independent Q for each accelerogram were computed simultaneously, and the estimated error was given in the rootmeansquare sense over the frequency range of interest. In this study, the generalized inversion method is used to estimate various source parameters as listed below. Thereby, it is estimated that the seismic moment range from 2.89E+23 to 1.21E+26 dynecm, average fault slip from 22 to 152 cm and average stress drop from 6 to 136 bars. The path average value Q are of the order Q=151537.
