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Estimations of the S-wave velocity structures in Chia-Yi City, Taiwan, using the array records of microtremors

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Abstract

Shear-wave velocities (VS) have been widely used for the site characterization of earthquake ground motion. We report here our investigation of the S-wave velocity structures of Chia-Yi City, Taiwan using the array records of microtremors at seven sites. The dispersion curves at these sites were first calculated using the F-K method proposed by Capon (1969); the S-wave velocity structures in Chia-Yi City were then estimated by employing the surface wave inversion technique (Herrmann, 1991). At frequencies lower than about 1 Hz, the propagation directions are concentrated in the northwest and southwest quadrants. The generation of these may be attributed to the ocean waves of the Taiwan Strait. The harder site (CBA) has higher phase velocities, while the softer sites (CWB, SHP and YRU) have lower phase velocities, especially at frequencies between 1 and 5 Hz. The shallow velocity structures (0–1,500 m) can be roughly divided into four to five layers. The depth of the alluvium gradually increases from east to west and from north to south.

References

  1. Capon, J., High-resolution frequency-wavenumber spectral analysis, Proc. IEEE., 57, 1408–1419, 1969.

  2. Chung, J. K. and Y. T. Yeh, Shallow crustal structure from short-period Rayleigh wave dispersion data in southwestern Taiwan, Bull. Seismol. Soc. Am., 87, 370–382, 1997.

  3. Herrmann, R. B., Surface wave inversion program (from computer program in Seismology volume IV), 1991.

  4. Ho, C. S., An Introduction to the Geology of Taiwan, Central Geology Survey, the Ministry of Economic Affairs, Taiwan, 1986.

  5. Horike, M., Inversion of phase velocity of long-period microtremors to the S-wave velocity structure down to the basement in urbanized area, J. Phys. Earth, 33, 59–96, 1985.

  6. Huang, H. C., Characteristics of earthquake ground motion and H/V of microtremor in the southwestern part of Taiwan, Earthquake Eng. Struct. Dyn., 31, 1815–1829, 2002.

  7. Huang, W. G. and Y. T. Yeh, The characteristics of microtremors at the site of SMART1 array, TAO, 1, 225–242, 1990.

  8. Hwang, R. D. and G. K. Yu, Shear-wave velocity structure of upper mantle under Taiwan from the array analysis of surface waves, Geophys. Res. Lett., 32, L07310, 2005.

  9. Hwang, R. D., G. K. Yu, W. Y. Chang, and J. P. Chang, Lateral variations shallow shear-wave structure in southern Taiwan inferred from short-period Rayleigh waves, Earth Planets Space, 55, 349–354, 2003.

  10. Jackson, D. D., Interpretation of inaccurate, insufficient, and inconsistent data, Geophys. J. R. Astron. Soc., 28, 97–109, 1972.

  11. Kawase, H., T. Satoh, T. Iwata, and K. Irikura, S-wave velocity structures in the San Fernando and Santa Monica area, Proc. of the 2nd International Symposium on Effect of Surface Geology on Seismic Motions, Tokyo, Japan, Vol. 2, 733–740, 1998.

  12. Kramer, S. L., Geotechnical Earthquake Engineering, Prentice-Hall, Upper Saddle River, New Jersey, 1996.

  13. Kudo, K., T. Kanno, H. Okada, O. Ozel, M. Erdik, T. Sasatani, S. Higashi, M. Takahashi, and K. Yoshida, Site-specific issues for strong ground motions during the Kocaeli, Turkey, earthquake of 17 August 1999, as inferred from array observations of microtremors and aftershocks, Bull. Seismol. Soc. Am., 92, 448–465, 2002.

  14. Lacoss, R. T., E. J. Kelly, and M. N., Tokoz, Estimation of seismic noise structure using array, Geophysics, 29, 21–38, 1969.

  15. Liu, H. P., D. M. Boore, W. B. Joyner, D. H. Oppenheimer, R. E. Warrick, W. Zhang, J. C. Hamilton, and L. T. Brown, Comparison of phase velocities from array measurement of Rayleigh waves associated with microtremor and results calculated from shear-wave velocity profiles, Bull. Seismol. Soc. Am., 90, 666–678, 2000.

  16. Mack, R. and E. A. Filnn, Analysis of the spatial coherence of short-period acoustic-gravity waves in the atmosphere, Geophys. J. R. Astron. Soc., 26, 255–269, 1971.

  17. Matsushima, T. and H. Okada, Determination of deep geological structures under urban areas using long-period microtremors, Butsuri-Tansa, 43, 21–33, 1990.

  18. Menke, W., Geophysical Data Analysis: Discrete Inversion Theory, Elsevier, New York, 1984.

  19. Satoh, T., H. Kawase, and S. Matsushima, Estimation of S-wave velocity structures in and around the Sendai basin, Japan, using array records of microtremors, Bull. Seismol. Soc. Am., 91, 206–218, 2001a.

  20. Satoh, T., H. Kawase, T. Iwata, S. Higashi, T. Sato, K. Irikura, and H. C. Huang, S-wave velocity structure of the Taichung basin, Taiwan, estimated from array and single-station records of microtremors, Bull. Seismol. Soc. Am., 91, 1267–1282, 2001b.

  21. Shih, R. C., The shallow velocity structure study in the Chia-Nan area (III), NSC Tech. Rep., Taiwan, 1995 (in Chinese).

  22. Shih, R. C. and Z. G. Fang, The shallow velocity structure study in the Chia-Nan area (II), NSC Tech. Rep. Taiwan, 1994 (in Chinese).

  23. Shih, R. C., Z. X. Hu, and R. J. Huang, The shallow velocity structure study in the Chia-Nan area (I), NSC Tech. Rep., Taiwan, 1993 (in Chinese).

  24. Wiggins, R. A., The general linear inverse problem: implication of surface waves and free oscillations for earth structure, Rev. Geophys. Space Phys., 10, 251–281, 1972.

  25. Woods, J. W. and P. R. Lintz, Plane waves at small array, Geophysics, 38, 1023–1041, 1973.

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Correspondence to Huey-Chu Huang.

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Huang, H., Wu, C. Estimations of the S-wave velocity structures in Chia-Yi City, Taiwan, using the array records of microtremors. Earth Planet Sp 58, 1455–1462 (2006) doi:10.1186/BF03352644

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Key words

  • Shear-wave velocity
  • microtremor
  • F-K method
  • surface wave inversion technique