Skip to main content

Volume 57 Supplement 6

Special Issue: Special Section for the 2004 Mid-Niigata Prefecture Earthquake (2)

Imaging of S-wave reflectors in and around the hypocentral area of the 2004 mid Niigata Prefecture Earthquake (M6.8)

Abstract

An S-wave reflector is considered to relate to the existence of liquid in the seismogenic zone of the crust, which plays an important role in understanding the mechanism of earthquakes. We studied a distribution of S-wave reflectors in and around the hypocentral zone of the 2004 mid Niigata Prefecture Earthquake (M6.8). The earthquake was followed by several aftershocks that were greater than M6. Moreover, the aftershocks were not only located on the fault plane of the main shock but also on conjugate fault planes and on a parallel plane to that of the main shock. In order to discuss the relationship between this complex activity and the crustal heterogeneities, we analyzed the seismograms observed at the seismic stations in this region. Normal moveout processing (NMO) was applied to the data of the aftershock. Several S-wave reflectors could be identified from the NMO sections for every station. In particular, relatively strong S-wave reflectors exist in the lower crust at a depth of approximately 20-25 km in the middle part of the aftershock region. Additionally, reflectors were found beneath the fault planes of the main shock and the largest aftershock. This suggests a possibility of the correlation of the crustal heterogeneities to the occurrence of an earthquake.

References

  • Kato, A., E. Kurashimo, N. Hirata, T. Iwasaki, and T. Kanazawa, Imaging the source region of the 2004 Mid-Niigata prefecture earthquake and the evolution of a seismogenic thrust-related fold, Geophys. Res. Lett., 2005 (in press).

  • Korenaga, M., S. Matsumoto, Y. Iio, T. Matsushima, K. Uehira, and T. Shibutani, Three dimensional velocity structure around aftershock area of the 2004 mid Niigata prefecture earthquake (M6.8) by the Double-Difference tomography, Earth Planets Space, 57, 429–433, 2005.

    Article  Google Scholar 

  • Matsumoto, S., K. Obara, and A. Hasegawa, Imaging P-wave scatterer distribution in the focal area of 1995 M7.2 Hyogo-ken Nanbu (Kobe) Earthquake, Geophys. Res. Lett., 25, 9, 1439–1442, 1998.

    Article  Google Scholar 

  • Matsumoto, S., K. Obara, N. Kimura, and M. Nakamura, Imaging P-wave scatterer distribution around the focal area of the 2000 Western Tottori Earthquake (Mw6.6), Zisin, 2, 55, 229–232, 2002 (in Japanese).

    Google Scholar 

  • Miyazawa, M., J. Mori, Y. Iio, T. Shibutani, S. Matsumoto, H. Katao, S. Ohmi, and K. Nishigami, Triggering Sequence by Static Stress Changes of Large aftershocks of the Niigata-Chuetsu, Japan Earthquake, Earth Planets Space, 2005 (submitted).

  • Okada, T., N. Umino, T. Matsuzawa, J. Nakajima, N. Uchida, T. Nakayama, S. Hirahara, T. Sato, S. Hori, T. Kono, Y. Yabe, K. Ariyoshi, S. Gamage, J. Shimizu, J. Suganomata, S. Kita, S. Yui, M. Arao, S. Hondo, T. Mizukami, H. Tsushima, T. Yaginuma, A. Hasegawa, Y. Asano, H. Zhang, and C. Thurber, Aftershock distribution and 3D seismic velocity structure in and around the focal area of the 2004 mid Niigata prefecture earthquake obtained by applying double-difference tomography to dense temporary seismic network data, Earth Planets Space, 57, 435–440, 2005.

    Article  Google Scholar 

  • Shibutani, T., Y. Iio, S. Matsumoto, H. Katao, T. Matsushima, S. Ohmi, F. Takeuchi, K. Uehira, K. Nishigami, B. Enescu, I. Hirose, Y. Kano, Y. Kohno, M. Korenaga, Y. Mamada, M. Miyazawa, K. Tatsumi, T. Ueno, H. Wada, and Y. Yukutake, Aftershock distribution of the 2004 Mid Niigata Prefecture Earthquake derived from a combined analysis of temporary online observations and permanent observations, Earth Planets Space, 57, this issue, 545–549, 2005.

    Article  Google Scholar 

  • Wada, H., T. Mikumo, and M. Koizumi, Seismicity and focal mechanism of local earthquakes along the Atotsugawafault and in the northern Hida region, Zisin, 2, 32, 3, 281–296, 1979.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Satoshi Matsumoto.

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

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Matsumoto, S., Iio, Y., Matsushima, T. et al. Imaging of S-wave reflectors in and around the hypocentral area of the 2004 mid Niigata Prefecture Earthquake (M6.8). Earth Planet Sp 57, 557–561 (2005). https://doi.org/10.1186/BF03352592

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03352592

Key words