HR: 0830h
AN: S51E-0106    [PDF]
TI: Estimation of site-dependent decay parameter $\kappa$ for strong motion simulation in southern Korea
AU: * Jo, N
EM: endyjo@seismic.snu.ac.kr
AF: School of Earth and Environmental Sciences, Seoul National University, San 56-1, Sillim-dong, Gwanak-gu, Seoul, 151-747 Korea, Republic of
AU: Baag, C
EM: baagce@snu.ac.kr
AF: School of Earth and Environmental Sciences, Seoul National University, San 56-1, Sillim-dong, Gwanak-gu, Seoul, 151-747 Korea, Republic of
AB: We estimated site-dependent decay parameter $\kappa$ using 1049 accelerograms of small earthquakes ({\it M}2.5-{\it M}4.0) in southern Korea occurring from January 1999 to April 2003. The spectral decay parameter $\kappa$ controls high-frequency contents of the model amplitude spectrum for the strong motion simulation using stochastic process. Generally, the $\kappa$ is defined by a 1st order equation in hypocentral distance (${R}$) as $\kappa_{s}$ + $\kappa_{q} {R}$. The conventional procedure for estimation of $\kappa$ cannot find the characteristics of the each site because it is for the computation of $\kappa$ for a wide area. We estimated site-independent $\kappa_{q}$ and dependent $\kappa_{s}$, separately. The procedure is to use the coda normalization method for the computation of site independent ${Q}$ or corresponding $\kappa_{q}$ as the first step followed by the next step, the computation of $\kappa_{s}$ for each site using the given $\kappa_{q}$ evaluated at the first step. With use of the technique, we found the distribution pattern of $\kappa_{s}$ in southern Korea.
DE: 7200 SEISMOLOGY
DE: 7203 Body wave propagation
DE: 7205 Continental crust (1242)
DE: 7212 Earthquake ground motions and engineering
SC: Seismology [S]
MN: 2003 Fall Meeting