Publication Date:
2017-05-31
Description:
The decay parameter at the high frequency (kappa value, ) introduced by Anderson and Hough (1984) is measured from 54 stations situated in and around the Taipei basin, northern Taiwan. Different frequency windows for the S -wave amplitude spectra are used to measure the r value for each individual record. The preferred r values are determined by the least-squared fitting with the best correlation coefficient. The site-specific 0 values, which are computed by removing the anelastic effect of regional geological structure by grouping r into the crustal and subduction events according to the focal depth and site classification (i.e., class B, C, D, and E sites), are calculated to be in the range of 0.034–0.066 s. We correlate the 0 values with the averaged shear-wave velocity of the topmost 30-m layer V S 30 and find the independence of 0 on V S 30 . In addition, 28 stations lie on sediment in the Taipei basin. The gradient of 0 versus the sedimentary thickness to the Tertiary base in the basin is calculated, and then used to estimate the effective quality factor Q ef of the layer. Q ef is 75.3 for the whole sedimentary layers (above the Tertiary base). Given one standard deviation, Q ef are in the 41.9–376.7 range. Q ef can provide an accurate referred parameter for the future ground-motion simulation applications.
Print ISSN:
0037-1106
Electronic ISSN:
1943-3573
Topics:
Geosciences
,
Physics
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