Skip to main content
  • Article
  • Published:

Present-day deformation across the southwest Japan arc: Oblique subduction of the Philippine Sea plate and lateral slip of the Nankai forearc

Abstract

We estimate long-term/permanent crustal deformation in the Nankai forearc, southwest Japan, that accumulated over one earthquake deformation cycle in the Nankai subduction zone. A short-term deformation due to an oblique subduction of the Philippine Sea plate is modeled based on coseismic fault slips associated with interplate thrust earthquakes at the Nankai Trough, and subtracted from the interseismic crustal velocity field observed by GPS. The long-term/permanent deformation left in the data shows arc-parallel movement of the forearc at a rate of 5— 10 mm/yr. We interpret that the forearc movement, driven by the oblique plate convergence, is accommodated by steady aseismic slip on the deep portion of the fault plane of the Median Tectonic Line (MTL) on the rear boundary of the Nankai forearc. The rate of the forearc movement is consistent with the geological slip rate of the MTL in the late Quaternary, and also with that expected from deflection of the slip vector of the 1946 Nankai earthquake from the current plate convergence vector.

References

  • Hatanaka, Y., T. Iizuka, M. Sawada, A. Yamagiwa, Y. Kikuta, J. M. Johnson, and C. Rocken, Improvement of the analysis strategy of GEONET, Bull. Geogr. Surv. Inst., 49, 11–37, 2003.

    Google Scholar 

  • Hyodo, M. and K. Hirahara, Modeling of stress accumulation process on inland faults in central Japan, Earth Planets Space, 2003 (submitted).

  • Ito, T., T. Ikawa, S. Yamakita, and T. Maeda, Gently north-dipping Median Tectonic Line (MTL) revealed by recent seismic reflection studies, southwest Japan, Tectonophysics, 264, 51–63, 1996.

    Article  Google Scholar 

  • Kanamori, H., Tectonic implications of the 1944 Tonankai and the 1946 Nankaido earthquakes, Phys. Earth Planet. Inter., 5, 129–139, 1972.

    Article  Google Scholar 

  • Kumagai, H., Time sequence and the recurrence models for large earthquakes along the Nankai trough revisited, Geophys. Res. Lett., 23, 1139–1142, 1996.

    Article  Google Scholar 

  • McCaffrey, R., Estimates of modern arc-parallel strain rates in fore arcs, Geology, 24, 27–30, 1996.

    Article  Google Scholar 

  • Miyazaki, S. and K. Heki, Crustal velocity field of southwest Japan: Subduction and arc-arc collision, J. Geophys. Res., 106, 4305–4326, 2001.

    Article  Google Scholar 

  • Nishimura, S., Kinematic features of tectonics of southwest Japan and the Rykyu Arcs revealed from the GPS derived velocity field, Dr. thesis, Graduate School of Science, Kyoto University, 2003.

  • Onoue, K., Y. Hoso, Y. Fujita, H. Doi, and T. Tanaka, Electro-optical measurements on Median Tectonic Line, Annals of Disast. Prev. Res. Inst., Kyoto Univ., 45B, 525–533, 2002 (in Japanese).

    Google Scholar 

  • Ozawa, S., M. Murakami, and T. Tada, Time-dependent inversion of the slow thrust event in the Nankai trough subduction zone, southwest Japan, J. Geophys. Res., 106, 787–802, 2001.

    Article  Google Scholar 

  • Research Group for Active Faults of Japan, Active Faults in Japan: Sheet Maps and Inventories, 437 pp, Univ. of Tokyo Press, 1991 (in Japanese).

  • 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 

  • Tabei, T., M. Hashimoto, S. Miyazaki, K. Hirahara, F. Kimata, T. Matsushima, T. Tanaka, Y. Eguchi, T. Takaya, Y. Hoso, F. Ohya, and T. Kato, Subsurface structure and faulting of the Median Tectonic Line, southwest Japan inferred from GPS velocity field, Earth Planets Space, 54, 1065–1070, 2002.

    Article  Google Scholar 

  • Tsutsumi, H. and A. Okada, Segmentation and Holocene surface faulting on the Median Tectonic Line, southwest Japan, J. Geophys. Res., 101, 5855–5871, 1996.

    Article  Google Scholar 

  • Wang, K., Stress-strain ‘paradox’, plate coupling, and forearc seismicity at the Cascadia and Nankai subduction zones, Tectonophysics, 319, 321–338, 2000.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Takao Tabei.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Tabei, T., Hashimoto, M., Miyazaki, S. et al. Present-day deformation across the southwest Japan arc: Oblique subduction of the Philippine Sea plate and lateral slip of the Nankai forearc. Earth Planet Sp 55, 643–647 (2003). https://doi.org/10.1186/BF03352471

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03352471

Key words