Deconvolution-linear scaling-convolution method for estimation of intensity measures near seismic stations

초록

This study aims to predict intensity measures (IMs) at sites nearby seismic stations using recorded ground motions at seismic stations. Ground motions attenuate by distance and amplify/de-amplify due to site effects. We estimate IMs at a site by deconvolution-linear scaling-convolution method. The first step of this method is to perform the deconvolution to a seismic record observed at a seismic station at surface. The deconvolved ground motion represents a bedrock-equivalent ground motion by offsetting linear site effect of the site. The second step is scaling the amplitude of the bedrock-equivalent ground motion to the target site considering site-to-source distance. In this step we assumed that bedrock motions within one earthquake event can be linearly interpolated by distance. The third step is convolving the scaled ground motion to obtain surface ground motion including site effect at the target site. Using this method, the prediction of ground motion IMs would be accurate if the station and the site are identical, and the accuracy would be decreased if station-to-site distance increases. We tested this method using seismic stations located closely, and provide the effectiveness per separation distance between a station and a target site.

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