Skip to main content

Volume 57 Supplement 4

Special Issue: Special Section for the 2004 off the Kii peninsula earthquakes (2)

The seismological and geodetical roles of strain seismogram suggested from the 2004 off the Kii peninsula earthquakes


Dynamic strain seismograms obtained by high-speed sampling include not only long-period changes, such as ‘strain-step’, step change in strain, but also short period variations, such as body waves. We studied dynamic strain variations caused by the 2004 off the Kii peninsula earthquakes. Using such strain seismograms, we clarified the relation between dynamic strain and velocity. Our results will contribute greatly to seismology. We also clarified the strain-step formation process. This result and the concept of dynamic strain will bring more information to geodetics.


  • Aki, K. and P. G. Richards, Quantitative Seismology, W. H. Freeman and Company, San Francisco, 932 pp., Second Edition, 2002, University Science Books, Sansalito, California, 699 pp., 1980.

    Google Scholar 

  • Asai, Y., M. Okubo, H. Ishii, H. Aoki, T. Yamauchi, Y. Kitagawa, N. Koizumi, and S. Azuma, Co-seismic strain-steps associated with the 2004 off the Kii peninsula earthquakes-Observed with Ishii-type borehole strainmeters and quartz-tube extensometers, Earth Planets Space, 57, this issue, 309–314, 2005.

    Article  Google Scholar 

  • Ishii, H., T. Yamauchi, S. Matsumoto, Y. Hirata, and S. Nakano, Seismo-genic Process Monitoring, edited by H. Ogasawara, T. Yanagitani, and M. Ando, A. A. Balkema, Tokyo, 414 pp, 2002.

  • Japan Meteorological Agency, Monthly Report on Earthquakes and Volcanoes in Japan October 2004, edited by Japan Meteorological Agency, 186, 2004.

    Google Scholar 

  • Koyama, J., N. V. Shestakov, and R. Honda, Strong ground motion recorded by High-rate sampling GPS at the closest site to the 2003 Tokachi-oki earthquake, Earth Planets Space, 56, 383–387, 2004.

    Article  Google Scholar 

  • Mikumo, T. and K. Aki, Determination of local phase velocity by inter-comparison of seismograms from strain and pendulum instruments, J. Geophys. Res., 69, 721–731, 1964.

    Article  Google Scholar 

  • Okada, Y., Theoretical strain seismogram and its applications, Bull. Earthq. Res. Inst. Tokyo Univ., 55, 101–168, 1980 (in Japanese with English abstract).

    Google Scholar 

  • Okada, Y., Confusions on the expressions in strain analysis, J. Seismol. Soc. Jpn 2, 34, 148–152, 1981 (in Japanese).

    Google Scholar 

  • Okubo, M., H. Ishii, and T. Yamauchi, The 2003 Tokachi-oki earthquake, observed by borehole strainmeter array—Comparison with broadband seismogram, J. Seismol. Soc. Jpn 2, 57, 105–114, 2004 (in Japanese with English abstract).

    Google Scholar 

  • Park, S-C. and J. Mori, The 2004 sequence of triggered earthquakes off the Kii peninsula, Japan, Earth, Planets Space, 57, this issue, 315–320, 2005.

    Article  Google Scholar 

  • Sacks, I. S., J. A. Snoke, R. E. G. King, and J. Beavan, Geophys. J. R. Astr. Soc., 46, 253–258, 1976.

    Article  Google Scholar 

  • Wideman, C. J. and M. W. Major, Strain steps associated with earthquakes, Bull. Seism. Soc. Am., 57, 1429–1444, 1967.

    Google Scholar 

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Makoto Okubo.

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

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Okubo, M., Asai, Y., Aoki, H. et al. The seismological and geodetical roles of strain seismogram suggested from the 2004 off the Kii peninsula earthquakes. Earth Planet Sp 57, 303–308 (2005).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

Key words