Skip to main content

Volume 60 Supplement 11

Special Issue: Special Section for the 2007 Chuetsu-oki, Niigata, Japan, Earthquake

Seismic vertical array analysis of the velocity structure and phase decomposition during aftershocks of the 2007 Chuetsu-oki earthquake


A velocity profile derived from PS-logging was examined using the mainshock and aftershock records from KK5 and KSH seismic vertical arrays in the Kashiwazaki-Kariwa nuclear power plant, which is located on the focal region. A seismic phase decomposition analysis method was applied to aftershock vertical array records. Peak frequencies of spectral ratios of the aftershock records from the KSH array between various depths were slightly different from those of theoretical transfer functions. A comparison of observed and theoretical S-wave travel times at various depths indicated that travel times for the mainshock measured by picking S-wave arrival times were identical to the theoretical travel times calculated from the PS-logging profile, although travel times for the aftershocks were different from the theoretical travel times. The decomposition analysis of seismic vertical array records from KK5 array for a small aftershock shows that a clear wave packet of surface waves follows just after the direct S-wave arrival. In contrast, a decomposition analysis of the KSH array records show that a wave packet of surface waves are not clearly discernable.


  • Aki, K. and P. G. Richards, Quantitative Seismology—Theory and methods, W. H. Freeman and Company, San Francisco, 1980.

    Google Scholar 

  • Archuleta, R. J. and J. H. Steidl, ESG studies in the United States: Results from borehole arrays, Proceedings of the Second International Symposium of the Effects of Surface Geology on Seismic Motion, 3–14, 1998.

    Google Scholar 

  • Saito, M., DISPER80: A subroutine package for the calculation of seismic normal-mode solutions, in Seismological Algorithms, edited by D. J. Doornbos, 293–319, Academic Press, San Diego, 1988.

    Google Scholar 

  • Wessel, P. and W. H. F. Smith, New, improved version of the Generic Mapping Tools released, EOS, Trans. AGU, 79, 579, 1998.

    Article  Google Scholar 

  • Yoshida, K. and T. Sasatani, A seismic phase decomposition method using vertical array records, Proceedings of the Third International Symposium on the Effects of Surface Geology on Seismic Motion, 175–184, 2006.

    Google Scholar 

  • Yoshida, K. and T. Sasatani, Seismic vertical array analysis for phase decomposition, Geophys. J. Int., 174, 707–718, 2008.

    Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Kunikazu Yoshida.

Rights and permissions

Open Access  This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

To view a copy of this licence, visit

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Yoshida, K. Seismic vertical array analysis of the velocity structure and phase decomposition during aftershocks of the 2007 Chuetsu-oki earthquake. Earth Planet Sp 60, 1143–1147 (2008).

Download citation

  • Published:

  • Issue Date:

  • DOI:

Key words

  • The 2007 Chuetsu-oki earthquake
  • seismic vertical array
  • site effect
  • non-linear soil response
  • seismic phase decomposition