Skip to main content

Volume 60 Supplement 10

Special Issue: Special Section for the 2007 Noto Hanto Earthquake (2)

Observation of ground motions of aftershocks of the 2007 Noto Hanto earthquake in Monzenmachi, the Wajima city, for estimation of site amplification

Abstract

Heavy damage occurred in Monzenmachi, the Wajima city, in the northern part of the Noto peninsula during the 2007 Noto Hanto earthquake with an Mj of 6.9. The area is located along a river and sandwiched by mountains at the northern and southern ends of a Quaternary narrow valley 1–2 km wide. The seismic intensity observed in the area was 6 upper during the main shock. In this study, we conducted observations of ground motions during aftershocks in Monzenmachi to understand local site effects in the vicinity of the seismic intensity station. We installed 11 accelerometers in three areas of Monzenmachi, Hashiride, Touge, and Kuroshima. In each area, three or five stations were chosen for a deployment of a linear array across the areas with heavy damage. The analysis was performed using aftershock records observed during events with Mj of 2.3–4.4. The spectral ratio of records from the station near the seismic intensity station to a reference station on Tertiary layers shows a dominant peak at a period of 1 s. We also found distinct peaks at periods of 0.4–0.7 s in the spectral ratios at the sites in the areas with heavy damage. In contrast, no dominant peaks were identified at the stations at the foot of the mountains. This clearly indicates that site amplification effects play an important role in defining the damage distribution in an area. Similar peaks were found in the H/V spectra of microtremors at the aftershock observation sites, though the peak amplitudes of the microtremor H/Vs are smaller than those of the S-wave spectral ratios.

References

  • Aoi, S., H. Sekiguchi, N. Morikawa, S. Senna, and T. Kunugi, Ground motion and rupture process of the 2007 Noto Hanto earthquake inferred from strong motion data of K-NET and Kik-net, Abstracts of Japan Geoscience Union meeting 2007, Z255–P006, 2007.

    Google Scholar 

  • Editing Committee of Engineering Geological Map in Hokuriku District, Engineering geological map of Hokuriku district 1:200,000, 1990.

    Google Scholar 

  • Lermo, J. and F. J. Chavez-Garcia, Are microtremors useful in site response evaluation?, Bull. Seismol. Soc. Am., 84, 1350–1364, 1994.

    Google Scholar 

  • Miura, H. and S. Midorikawa, Characteristics of microtremors on strong motion observation stations in the 2007 Noto-Hanto earthquake, Abstracts of Japan Geoscience Union meeting 2007, Z255–P042, 2007.

    Google Scholar 

  • Moroi, T., M. Kamata, T. Ikeda, and K. Kanda, Relationship between seismic intensity and regional damage due to the 2007 Noto Hanto earthquake, Abstracts of Japan Geoscience Union meeting 2007, Z255–P043, 2007.

    Google Scholar 

  • Nakamura, Y., A method for dynamic characteristics estimation of subsurface using microtremor on the ground surface, Q. Report of Railr. Tech. Res. Inst., 30, 25–33, 1989.

    Google Scholar 

  • National Institute for Land and Infrastructure Manegement and Building Research Institute, Quick report of survey for the 2007 Noto Hanto earthquake (’07.3.26–27), http://www.kenken.go.jp/japanese/contents/activities/other/disaster/jishin/2007noto/houkokusho/200704061600/index.pdf, 19, 2007.

    Google Scholar 

  • Wessel, P. and W. H. F. Smith, Free software helps map and display data, EOS, Trans. AGU, 72, 441, 445–446, 1991.

    Google Scholar 

  • Yoshimi, M., K. Yoshida, H. Sakamoto, and I. Cho, Temporal strong motion observation of aftershocks of the 2007 Noto Peninsula earthquake, Abstracts of Japan Geoscience Union meeting 2007, Z255–P037, 2007.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Hiroaki Yamanaka.

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 https://creativecommons.org/licenses/by/4.0/.

Reprints and Permissions

About this article

Cite this article

Yamanaka, H., Motoki, K., Yamada, N. et al. Observation of ground motions of aftershocks of the 2007 Noto Hanto earthquake in Monzenmachi, the Wajima city, for estimation of site amplification. Earth Planet Sp 60, 1063–1067 (2008). https://doi.org/10.1186/BF03352870

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03352870

Key words

  • 2007 Noto Hanto earthquake
  • local site effect
  • amplification
  • aftershock observation
  • Wajima city
  • microtremors