Earth, Planets and Space

, Volume 57, Issue 5, pp 429–433 | Cite as

Three dimensional velocity structure around aftershock area of the 2004 mid Niigata prefecture earthquake (M6.8) by the Double-Difference tomography

  • Masahiro Korenaga
  • Satoshi Matsumoto
  • Yoshihisa Iio
  • Takeshi Matsushima
  • Kenji Uehira
  • Takuo Shibutani
Open Access
Letter

Abstract

The 2004 mid Niigata prefecture earthquake with M6.8 occurred in the north of central part of Japan. It was a reverse fault by the regional compression stress field in NW-SE direction. Several aftershocks with M≥6 were occurred. The large aftershocks occurred on plural fault planes. The plane was either parallel or normal to the main shock one. We estimated three dimensional velocity structures in and around the focal area of the earthquake by using a Double Difference tomography method. The arrival time data were picked from seismograms at the deployed seismic stations settled by Kyoto and Kyushu universities in collaboration, NIED, ERI, and JMA. The velocity structure showed that a low velocity zone existed in the northwest part of the aftershock area. On the contrary, the velocity in the southeast became high. Moreover, the fault plane of the main shock inferred from the aftershock distribution was located at the velocity boundary.

Key words

Velocity structure DD tomography 2004 mid Niigata prefecture earthquake 

References

  1. Aoki, S., M. Nishi, K. Nakamura, T. Hashimoto, S. Yoshikawa, H. M. Ito, Multi-planar structures in the aftershock distribution of the Mid Niigata prefecture Earthquake in 2004, Earth Planets Space, 57, this issue, 403–409, 2005.CrossRefGoogle Scholar
  2. 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).Google Scholar
  3. Honda, R., S. Aoi, N. Morikawa, H. Sekiguchi, T. Kunugi, and H. Fujiwara, Ground Motion and Rupture Process of the 2004 Mid Niigata Prefecture Earthquake Obtained from Strong Motion Data of K-NET and KiK-net, Earth Planets Space, 2005 (submitted).Google Scholar
  4. Okada, T., A. Hasegawa, J. Suganomata, N. Umino, H. Zhang, and C. Thurber, Imaging the fault plane and asperities of the 2003 M6.4 northern Miyagi earthquake, NE Japan, by double-difference tomography, Earth. Planet. Sci. Lett., 2005a (submitted).Google Scholar
  5. 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, this issue, 435–440, 2005b.CrossRefGoogle Scholar
  6. Sakai, S., N. Hirata, A. Kato, E. Kurashimo, T. Iwasaki, and T. Kanazawa, Multi-fault system of the 2004 Mid-Niigata Prefecture Earthquake and its aftershocks, Earth Planets Space, 57, this issue, 417–422, 2005.CrossRefGoogle Scholar
  7. 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 Niigata- Chuetsu Earthquake (Mj = 6.8) and Heterogeneous Structure in and Around the Source Region, Earth Planets Space, 57, 2005 (submitted).Google Scholar
  8. Zhang, H. and C. Thurber, Double-Difference Tomography: the method and its application to the Hayward Fault, California, Bull. Seism. Soc. Am., 93, 1875–1889, 2003.CrossRefGoogle Scholar

Copyright information

© The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences. 2005

Authors and Affiliations

  • Masahiro Korenaga
    • 1
  • Satoshi Matsumoto
    • 2
  • Yoshihisa Iio
    • 3
  • Takeshi Matsushima
    • 2
  • Kenji Uehira
    • 2
  • Takuo Shibutani
    • 3
  1. 1.Graduate School of SciencesKyushu UniversityShimabara, NagasakiJapan
  2. 2.Institute of Seismology and Volcanology, Faculty of ScienceKyushu University, JapanShimabara, NagasakiJapan
  3. 3.Research Center for Earthquake Prediction, Disaster Prevention Research InstituteKyoto UniversityGokasho, Uji, KyotoJapan

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