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Preparatory process reflected in seismicity-pattern change preceding the M=7 earthquakes off Miyagi prefecture, Japan

Abstract

Two M=7 interplate earthquakes recently occurred off Miyagi prefecture, northeastern Japan. These belong to a new sequence of earthquake series. The occurrence of this sequence was forewarned by the government, based primarily on a statistical approach utilizing historical records. Such a process, however, does not account for the present on-going status in the assessment. During the stage when stress approaches a critical level, there is a possibility of stress redistribution caused by a quasi-static slip, which will be reflected in a temporal change in seismic activity. Delineating a spatial map of the seismic-activity rate changes in the seismogenic zone off Miyagi prefecture, we found that there was an activation of microseismicity in the rupture zones several months prior to both M=7 earthquakes. This was interpreted as evidence of a preparatory process preceding each M=7 earthquake, during which a quasi-static slip progressed, driving stress redistribution and resulting in stress concentration on asperities of these earthquakes.

References

  1. Dieterich, J., A constitutive law for rate of earthquake production and its application to earthquake clustering, J. Geophys. Res., 99, 2601–2618, 1994.

    Article  Google Scholar 

  2. Earthquake Research Committee, Reports on probabilistic evaluation map for seismic ground motion in Japan, 213 pp, 2005a (in Japanese).

    Google Scholar 

  3. Earthquake Research Committee, Earthquake off-shore of Miyagi prefecture on August 16, 2005, http://www.jishin.go.jp/main/index-html, 2005b.

    Google Scholar 

  4. Igarashi, T., T. Matsuzawa, and A. Hasegawa, Repeating earthquakes and interplate aseismic slip in the northeastern Japan subduction zone, J. Geophys. Res., 108(B5), 2249, doi:10.1029/2002JB001920, 2003.

    Article  Google Scholar 

  5. Japan Meteorological Agency, Earthquake of M6.8 off Fukushima prefecture on October 31, 2003, Rep. Coord. Comm. Earthq. Pred., 71, 246–251, 2004 (in Japanese).

    Google Scholar 

  6. Japan Meteorological Agency, An outlook of seismic activity in Japan, 2005/8-2005/9, Newslet. Seismol. Soc. Jpn., 17, 19–23, 2005 (in Japanese).

    Google Scholar 

  7. Jimenez, A., K. F. Tiampo, S. Levin, and A. M. Posadas, Testing the persistence in earthquake catalogs: The Iberian Peninsula, Europhys. Lett., 73, 171–177, 2006.

    Article  Google Scholar 

  8. Matsumura, S., Why does the precursory change of seismicity rate tend to be quiescence?, Zisin, 57, 441–444, 2005a (in Japanese).

    Google Scholar 

  9. Matsumura, S., Seismic activity changes progressing simultaneously with slow-slip in the Tokai area, Tectonophysics, 417, 5–15, 2005b.

    Article  Google Scholar 

  10. Matsuzawa, T., N. Uchida, T. Igarashi, T. Okada, and A. Hasegawa, Repeating earthquakes and quasistatic slip on the plate boundary east off northern Honshu, Japan, Earth Planets Space, 56, 803–811, 2004.

    Article  Google Scholar 

  11. Ogata, Y., Detection of anomalous seismicity as a stress change sensor, J. Geophys. Res., 110, B05S06, doi:10.1029/2004JB003245, 2005.

    Google Scholar 

  12. Ruina, A., Slip instability and state variable friction laws, J. Geophys. Res., 88, 10359–10370, 1983.

    Article  Google Scholar 

  13. Seno, T., On the earthquake expected off the Miyagi prefecture, Rep. Coord. Comm. Earthq. Pred., 21, 38–41, 1979 (in Japanese).

    Google Scholar 

  14. Stein, R. S., The role of stress transfer in earthquake occurrence, Nature, 402, 605–609, 1999.

    Article  Google Scholar 

  15. Tiampo, K. F., J. B. Rundle, S. McGinnis, and S. J. Gross, Eigenpatterns in southern California seismicity, J. Geophys. Res., 107(B12), 2354, doi:10.1029/2001JB000562, 2002.

    Article  Google Scholar 

  16. Toda, S., R. S. Stein, and T. Sagiya, Evidences from the AD 2000 Izu islands earthquake swarm that stressing rate governs seismicity, Nature, 419, 6902, 58–61, 2002.

    Article  Google Scholar 

  17. Wessel, P. and W. H. F. Smith, New version of the Generic Mapping Tools released, Eos Trans. AGU, 76, 329, 1995.

    Article  Google Scholar 

  18. Wiemer, S., A software package to analyze seismicity: ZMAP, Seism. Res. Lett., 72, 374–383, 2001.

    Article  Google Scholar 

  19. Wiemer, S. and M. Wyss, Seismic quiescence before the Landers (M=7.5) and Big Bear (M=6.5) 1992 earthquakes, Bull. Seismol. Soc. Am., 84, 900–916, 1994.

    Google Scholar 

  20. Wiemer, S. and M. Wyss, Mapping the frequency-magnitude distribution in asperities: An improved technique to calculate recurrence times?, J. Geophys. Res., 102, 15115–15128, 1997.

    Article  Google Scholar 

  21. Wyss, M., Seismic quiescence precursor to the 1983 Kaoiki (Ms=6.6), Hawaii, earthquake, Bull. Seismol. Soc. Am., 76, 785–800, 1986.

    Google Scholar 

  22. Wyss, M. and R. E. Habermann, Precursory quiescence before the August 1982 Stone Canyon, San Andreas fault, earthquakes, Pageophysics, 126, 333–356, 1988.

    Google Scholar 

  23. Wyss, M., F. W. Klein, and A. C. Johnston, Precursors to the Kalapana M=7.2 earthquake, J. Geophys. Res., 86, 3881–3900, 1981.

    Article  Google Scholar 

  24. Yamanaka, K. and M. Kikuchi, Asperity map along the subduction zone in northern Japan inferred from regional seismic data, J. Geophys. Res., 109, B07307, doi:10,1029/2003JB002683, 2004.

    Google Scholar 

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Correspondence to Shozo Matsumura.

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Matsumura, S. Preparatory process reflected in seismicity-pattern change preceding the M=7 earthquakes off Miyagi prefecture, Japan. Earth Planet Sp 58, 1581–1586 (2006). https://doi.org/10.1186/BF03352665

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Key words

  • Microseismicity
  • stress redistribution
  • asperity
  • preparatory process