Site Correction of a High-Frequency Strong-Ground-Motion Simulation Based on an Empirical Transfer Function

Site Correction of a High-Frequency Strong-Ground-Motion Simulation Based on an Empirical Transfer Function

This study constructs an empirical transfer function(ETF) for the difference in frequency spectra between the observed strong ground motion and the synthetic motion of a stochastic point-source approach(Boore, 1983; Boore, 2003) for the Taipei Basin, Taiwan. A database of shallow, small-magnitude earthquakes was selected to construct the ETF so that the point-source approach for synthetic motions might be made more widely applicable. Site corrections for high-frequency synthetic motion from the ETF procedure are made in the strong site-response area of the Taipei Basin. Finally, one of the most significant shallow large earthquakes(the 1999 Chi-Chi earthquake in Taiwan) is verified in this study. A finite fault stochastic simulation technique(Beresnev and Atkinson, 1998; Motezedian and Atkinson, 2005; Boore, 2009) is applied, owing to the complexity of the fault rupture process in the Taipei Basin, and the ETF-based site correction function is multiplied to obtain a precise simulation of high-frequency(up to 10 Hz) strong motions. The high-frequency prediction has good agreement in both the time and frequency domains in this study and it reached the same level as that predicted by the site-corrected ground motion prediction equation(GMPE, Jean et al., 2006; Chang et al., 2010; Lin, 2009).