Skip to main content

Advertisement

We’d like to understand how you use our websites in order to improve them. Register your interest.

Characteristic activity and migration of episodic tremor and slow-slip events in central Japan

Abstract

Continuous seismic data and tilt measurements in the Aichi and Mie regions of central Japan indicate significant migration of episodic non-volcanic deep tremors and short-term slow-slip events on the subducting plate interface at the deeper extension of the mega-thrust earthquake seismogenic zone. These episodic tremor and slip (ETS) events occur in two concentrated regions on either side of Ise Bay at recurrence intervals of approximately every 6 months throughout 2004 and 2005, separated by a distinct tremor gap. A migrating tremor episode from the southern edge of the Mie region in January 2006, however, is found to have crossed aseismic Ise Bay along a continuous 200 km long strike of the subducting Philippine Sea Plate. Coincident with the migration of tremors, very low frequency earthquakes with a predominant frequency of 0.05 Hz and tilt changes lasting for a few days were detected. Inversion analysis of the tilt data indicates that at least five reverse faultings with an average slip length of 1 cm took place on the plate boundary, migrating from southwest to northeast, equivalent to a total moment release of Mw 6.2. The tremor seismicity gap at Ise Bay is attributed to the presence of a small ridge in the Philippine Sea Plate that blocks most propagating ETS events. The 2006 episode propagated orthogonal to the majority of ETS event in this region, and was found not to be obstructed by the ridge structure.

References

  1. Ando, M., Source mechanisms and tectonic significance of historical earthquakes along the Nankai trough, Japan, Tectonophys., 27, 119–140, 1975.

    Article  Google Scholar 

  2. Dragert, H., K. Wang, and T. S. James, A silent slip event on the deeper Cascadia subduction interface, Science, 292, 1525–1528, 2001.

    Article  Google Scholar 

  3. Dragert, H., K. Wang, and G. Rogers, Geodetic and seismic signatures of episodic tremor and slip in the northern Cascadia subduction zone, Earth Planets Space, 56, 1143–1150, 2004.

    Article  Google Scholar 

  4. Hirose, H. and K. Obara, Repeating short- and long-term slow slip events with deep tremor activity around the Bungo channel region, southwest Japan, Earth Planets Space, 57, 961–972, 2005.

    Article  Google Scholar 

  5. Hirose, H. and K. Obara, Short-term slow slip and correlated tremor episodes in the Tokai region, central Japan, Geophys. Res. Lett., 33, L17311, doi:10.1029/2006GL026579, 2006.

    Article  Google Scholar 

  6. Hyndman, R. D., M. Yamano, and D. A. Oleskevich, The seismogenic zone of subduction thrust faults, Island Arc, 6, 244–260, 1997.

    Article  Google Scholar 

  7. Ito, Y., K. Obara, K. Shiomi, S. Sekine, and H. Hirose, Slow earthquakes coincident with episodic tremors and slow slip events, Science, 315, 503–506, 2007.

    Article  Google Scholar 

  8. Kobayashi, A., T. Yamamoto, K. Nakamura, and K. Kimura, Short-term slow slip events detected by the strainmeters in Tokai region in the period from 1984 to 2005, Zisin, 59, 2006 (in Japanese with English abstract).

  9. Matsubara, M., K. Obara, and K. Kasahara, Three-dimensional P- and S-wave velocity structures beneath the Japan Islands obtained by high-density seismic stations by seismic tomography, Tectonophys., doi:10.1016/j.tecto.2008.04.016, 2008.

    Google Scholar 

  10. Melbourne, T. I., W. M. Szeliga, M. M. Miller, and V. M. Santillan, Extent and duration of the 2003 Cascadia slow earthquake, Geophys. Res. Lett., 32, L04301, doi:10.1029/2004GL021790, 2005.

    Article  Google Scholar 

  11. Miller, M. M., T. Melbourne, D. J. Johnson, and W. Q. Sumner, Periodic slow earthquakes from the Cascadia subduction zone, Science, 295, 2423, 2002.

    Article  Google Scholar 

  12. Obara, K., Nonvolcanic deep tremor associated with subduction in southwest Japan, Science, 296, 1679–1681, 2002.

    Article  Google Scholar 

  13. Obara, K. and H. Hirose, Non-volcanic deep low-frequency tremors accompanying slow slips in the southwest Japan subduction zone, Tectonophys., 417, 33–51, 2006.

    Article  Google Scholar 

  14. Obara, K., H. Hirose, F. Yamamizu, and K. Kasahara, Episodic slow slip events accompanied by non-volcanic tremors in southwest Japan subduction zone, Geophys. Res. Lett., 31, L23602, doi:10. 1029/2004GL020848, 2004.

    Article  Google Scholar 

  15. Obara, K., K. Kasahara, S. Hori, and Y. Okada, A densely distributed highsensitivity seismograph network in Japan: Hi-net by National Research Institute for Earth Science and Disaster Prevention, Rev. Sci. Instrum., 76, 021301, doi:10.1063/1.1854197, 2005.

  16. Okada, Y., Internal deformation due to shear and tensile faults in a halfspace, Bull. Seismol. Soc. Am., 82, 1018–1040, 1992.

    Google Scholar 

  17. Okada, Y., K. Kasahara, S. Hori, K. Obara, S. Sekiguchi, H. Fujiwara, and A. Yamamoto, Recent progress of seismic observation networks in Japan—Hi-net, F-net, K-NET and KiK-net, Earth Planets Space, 56, xv–xxviii, 2004.

    Article  Google Scholar 

  18. Rogers, G. and H. Dragert, Episodic tremor and slip on the Cascadia subduction zone: The chatter of silent slip, Science, 300, 1942–1943, 2003.

    Article  Google Scholar 

  19. Sagiya, T. and W. Thatcher, Coseismic slip resolution along a plate boundary megathrust: The Nankai Trough, southwest Japan, J. Geophys. Res., 104, 1111–1129, 1999.

    Article  Google Scholar 

  20. Shelly, D. R., G. C. Beroza, S. Ide, and S. Nakamula, Low-frequency earthquakes in Shikoku, Japan and their relationship to episodic tremor and slip, Nature, 442, 188–191, doi:10.1038/nature04931, 2006.

    Article  Google Scholar 

  21. Shiomi, K., M. Matsubara, Y. Ito, and K. Obara, Simple relationship between seismic activity along Philippine Sea slab and geometry of oceanic Moho beneath southwest Japan, Geophys. J. Int., 173, 1018–1029, 2008.

    Article  Google Scholar 

  22. Szeliga, W., T. I. Melbourne, M. M. Miller, and V. M. Santillan, Southern Cascadia episodic slow earthquakes, Geophys. Res. Lett., 31, L16602, doi:16610.11029/12004GL020824, 2004.

    Article  Google Scholar 

  23. Tamura, Y., T. Sato, M. Ooe, and M. Ishiguro, A procedure for tidal analysis with a Bayesian information criterion, Geophys. J. Int., 104, 507–516, 1991.

    Article  Google Scholar 

  24. Wessel, P. and W. H. F. Smith, New, improved version of Generic Mapping Tools released, EOS Trans. AGU, 79(47), 579, 1998.

    Article  Google Scholar 

  25. Yoshida, S. and N. Kato, Episodic aseismic slip in a two-degree-offreedom block-spring model, Geophys. Res. Lett., 30, 1681, doi:10. 11029/2003GL017439, 2003.

    Article  Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Kazushige Obara.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Obara, K., Sekine, S. Characteristic activity and migration of episodic tremor and slow-slip events in central Japan. Earth Planet Sp 61, 853–862 (2009). https://doi.org/10.1186/BF03353196

Download citation

Key words

  • Non-volcanic tremor
  • slow-slip event
  • subduction zone
  • plate interface
  • transition zone
  • migration