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  • Article
  • Open Access

Change of strain rate and seismicity in the Chubu district, central Japan, associated with a Tokai slow event

Earth, Planets and Space200759:BF03352695

  • Received: 14 June 2006
  • Accepted: 27 February 2007
  • Published:


We have evaluated temporal variation in strain rates in the Chubu and Kinki districts, central Japan, between 1997 and 2004 using continuous GPS data of GEONET. We found that strain rates throughout the southern part of Chubu district, including the Yoro fault and Nobi fault zone, have significantly deviated from the secular crustal deformation pattern since at least 2001. The results of an inversion procedure show that the strain rate change can be well explained by a slow slip beneath the Tokai area, suggesting that the Tokai slow event has significantly affected the crustal deformation not only in the Tokai area but also in an area located more than 100 km from the main slip area of the event. We also found that the seismicity rate has clearly decreased by approximately 50% around the Yoro fault since the latter half of 2000. The δCFF inferred from our Tokai slow slip model agrees with the observed reduction in seismicity. These results were interpreted as indicating that the seismicity, which has been decreasing for several years, is controlled by the reduction in the shear stressing-rate due to the Tokai slow slip.

Key words

  • Strain rate change
  • seismicity change
  • Tokai slow event
  • static stress change

Authors’ Affiliations

Disaster Prevention Research Institute, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
Present address: Institute of Seismology and Volcanology, Graduate School of Science, Hokkaido University, Kita 10 nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan


  1. Akaike, H., Likelihood and the Bayes procedure, in Bayesian Statistics, edited by J. M. Bernardo, M. H. DeGroot, D. V. Lindley, and A. F. M. Smith, 143–166 pp., University Press, Valencia, Spain, 1980.Google Scholar
  2. Dieterich, J., A constitutive law for rate of earthquake production and its application to earthquake clustering, J. Geophys. Res., 99, 2601–2618, 1994.View ArticleGoogle Scholar
  3. Habermann, R. E., Teleseismic detection in the Aleutian Island Arc, J. Geophys. Res., 88, 5056–5064, 1983.View ArticleGoogle Scholar
  4. Harris, R. A. and R. W. Simpson, Changes in static stress on southern California faults after the 1992 Landers earthquake, Nature, 360, 251–254, 1992.Google Scholar
  5. Hashimoto, M., Static Stress Changes Associated with the Kobe Earthquake: Calculation of Changes in Coulomb Failure Function and Comparison with Seismicity Change, J. Seismol. Soc. Japan, 48, 521–530, 1995 (in Japanese with English abstract). (Correction to “Static Stress Changes Associated with the Kobe Earthquake: Calculation of Changes in Coulomb Failure Function and Comparison with Seismicity Change”, J. Seismol. Soc. Japan, 50, 21–27, 1997.)Google Scholar
  6. Hashimoto, M., K. Onoue, F. Ohya, Y. Hoso, K. Segawa, K. Sato, and Y. Fujita, Crustal deformations in Kii peninsula associated with the SE off the Kii peninsula earthquake sequence of September 5, 2004 derived from dense GPS observations, Earth Planets Space, 57, 1–6, 2005.View ArticleGoogle Scholar
  7. Ishida, M., Geometry and relative motion of the Philippine sea plate and Pacific plate beneath the Kanto-Tokai district, Japan, J. Geophys. Res., 97, 489–513, 1992.View ArticleGoogle Scholar
  8. Jaume, S. C. and L. R. Sykes, Change in the state of stress on the southern San Andreas fault resulting from the California earthquake sequence of April to June 1992, Science, 258, 1325–1328, 1992.View ArticleGoogle Scholar
  9. Kimata, F., K. Hirahara, N. Fujii, and H. Hirose, Repeated occurrence of slow slip events on the subducting plate interface in the Tokai region, central Japan, the focal region of the anticipated Tokai earthquake (M=8), EOS Trans. AGU Fall Meeting Suppl., 82, 2001.Google Scholar
  10. Kobayashi, A. and A. Yoshida, Recurrence of the Tokai slow slip inferred from the tide gauge data at Maisaka, J. Geod. Soc. Jpn., 50, 209–212, 2004 (in Japanese with English abstract).Google Scholar
  11. Kobayashi, A., A. Yoshida, T. Yamamoto, and H. Takayama, Slow slip in the focal region of the anticipated Tokai earthquake following the seismo-volcanic event in the northern Izu Islands in 2000, Earth Planets Space, 57, 507–513, 2005.View ArticleGoogle Scholar
  12. Matsumura, S., Seismicity rate changes in the inferred locked zone of the Tokai region in the latter half of 1990’s, J. Seismol. Soc. Japan, 54, 449–463, 2002 (in Japanese with English abstract).Google Scholar
  13. Matsumura, S., Seismicity activity and its change beneath Lake Hamana in the Tokai region (Seismic activity change in the Tokai region: Part 3), J. Seismol. Soc. Japan, 58, 55–65, 2005 (in Japanese with English abstract).Google Scholar
  14. Miyoshi, T. and K. Ishibashi, Geometry of the seismic Philippine Sea slab beneath the region from Ise Bay to western Shikoku, southwest Japan, J. Seismol. Soc. Japan, 57, 139–152, 2004 (in Japanese with English abstract).Google Scholar
  15. Nishimura, T., S. Ozawa, M. Murakami, T. Sagiya, T. Tada, M. Kaidzu, and M. Ukawa, Crustal deformation caused by magma migration in the northern Izu Islands, Japan, Geophys. Res. Lett., 28, 3745–3748, 2001.View ArticleGoogle Scholar
  16. Okada, Y., Surface deformation due to shear and tensile faults in a halfspace, Bull. Seismol. Soc. Am., 75, 1135–1154, 1985.Google Scholar
  17. Ozawa, S., M. Murakami, M. Kaidzu, T. Tada, T. Sagiya, Y. Hatanaka, H. Yarai, and T. Nishimura, Detection and monitoring of ongoing aseismic slip in the Tokai region, central Japan, Science, 298, 1009–1012, 2002.View ArticleGoogle Scholar
  18. Ozawa, S., S. Miyazaki, T. Nishimura, M. Murakami, M. Kaidzu, T. Imakiire, and X. Ji, Creep, dike intrusion, and magma chamber deflation model for the 2000 Miyake eruption and the Izu islands earthquakes, J. Geophys. Res., 109, doi:10.1029/2003JB002601, 2004.Google Scholar
  19. Ozawa, S., M. Murakami, M. Kaidzu, and Y. Hatanaka, Transient crustal deformation in Tokai region, central Japan, until May 2004, Earth Planets Space, 57, 909–915, 2005.View ArticleGoogle Scholar
  20. Reasenberg, P., Second-order moment of Central California seismicity, 1969–1982, J. Geophys. Res., 90, 5479–5495, 1985.View ArticleGoogle Scholar
  21. Sagiya, T., S. Miyazaki, and T. Tada, Continuous GPS array and presentday crustal deformation of Japan, Pure. Appl. Geophys., 157, 2303–2322, 2000.Google Scholar
  22. Shen, Z., D. D. Jackson, and B. X. Ge, Crustal Deformation Across and Beyond the Los Angels Basin from Geodetic Measurements, J. Geophys. Res., 101, 27951–27980, 1996.Google Scholar
  23. Stein, R. S., The role of stress transfer in earthquake occurrence, Nature, 402, 605–609, 1999.View ArticleGoogle Scholar
  24. Stein, R. S., G. C. P. King, and J. Lin, Change in failure stress on the southern San Andreas fault system caused by the 1992 magnitude=7.4 Landers earthquake, Science, 258, 1328–1332, 1992.View ArticleGoogle Scholar
  25. Stein, R. S., G. C. P. King, and J. Lin, Stress triggering of the 1994 M=6.7 Northridge, California earthquake by its predecessors, Science, 265, 1432–1435, 1994.View ArticleGoogle Scholar
  26. Toda, S., R. S. Stein, P. A. Reasenberg, J. H. Dieterich, and A. Yoshida, Stress transferred by the 1995 Mw = 6.9 Kobe, Japan, shock: Effect on aftershocks and future earthquake probabilities, J. Geophys. Res., 103, 24543–24565, 1998.View ArticleGoogle Scholar
  27. Toda, S. and R. S. Stein, Response of the San Andreas fault to the 1983 Coalinga-Nuñez earthquake: An application of interactionbased probabilities for Parkfield, J. Geophys. Res., 107, doi: 10.1029/2001JB000172, 2002.Google Scholar
  28. Toda, S., R. S. Stein, and T. Sagiya, Evidence from the AD 2000 Izu islands earthquake swarm that stressing rate governs seismicity, Nature, 419, 58–61, 2002.View ArticleGoogle Scholar
  29. Wessel, P. and W. H. Smith, New, improved version of Generic Mapping Tools released, EOS Trans. Am. Geophys. Union, 79, 579, 1998.View ArticleGoogle Scholar
  30. Yoshikawa, S., Space and time variation of strain promoted by the slow slip event in the Tokai area revealed by GPS data, Bull. Earthq. Res. Inst., 78, 255–267, 2003.Google Scholar


© 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. 2007