Skip to main content

Volume 57 Supplement 3

Special Issue: Special Section for the 2004 off the Kii peninsula earthquakes (1)

Resistivity image of the Philippine Sea Plate around the 1944 Tonankai earthquake zone deduced by Marine and Land MT surveys

Abstract

The Nankai Trough is an active convergent region in southwest Japan and mega-thrust earthquakes have repeatedly occurred in some areas of its plate-boundary interface. Generation of mega-thrust earthquakes is inferred to be related to the existence of water. The resistivity structure is very sensitive to the existence of water. For that reason, it is important to obtain the resistivity image around the rupture area of mega-thrust earthquakes. We carried out land and marine magnetotelluric surveys in the Kii Peninsula and the offshore Kii Peninsula where the 1944 Tonankai earthquake occurred. We constructed a 2D resistivity model using an inversion technique. The modeled resistivity structure portrayed the Philippine Sea Plate as a resistive region. However, its resistivity becomes more conductive as the plate subducts, showing 10 Ω-m around the down-dip limit. These characteristics are considered to relate to the water. Therefore, we infer that water might control the generation of mega-thrust earthquakes.

References

  • Ando, M., Source mechanisms and tectonic significance of historical earthquakes along the Nankai Trough, Japan, Tectonophysics, 27, 119–140, 1975.

    Article  Google Scholar 

  • Chave, A. D., D. J. Thomson, and M. E. Ander, On the robust estimation of power spectra, coherences, and transfer functions, J. Geophys. Res., 92, 633–648, 1987.

    Article  Google Scholar 

  • Fuji-ta, K., Y. Ogawa, S. Yamaguchi, and K. Yaskawa, Magnetotelluric imaging of the SW Japan forearc,—a lost paleoland revealed?—, Phys. Earth Planet Inter., 102, 231–238, 1997.

    Article  Google Scholar 

  • Gamble, T. D., W. M. Goubau, and J. Clarke, Magnetotellurics with a remote magnetic reference, Geophysics, 44, 53–68, 1979.

    Article  Google Scholar 

  • Goto, T., T. Watanabe, T. Nagaoka, T. Matsuoka, T. Sugano, Y. Ashida, H. Mikada, and K. Suyehiro, Inversion of marine magnetotelluric survey data at offshore Fukushima., Proceedings of the 106th SEGJ Conference, 221–224, 2002 (in Japanese).

    Google Scholar 

  • Goto, T., T. Kasaya, H. Mikada, M. Kinoshita, K. Suyehiro, T. Kimura, Y. Ashida, T. Watanabe, and K. Yamane, Electromagnetic survey of fluid distribution and migration -An example at the Nankai seismogenic zone-, Butsuri Tansa (Geophys. Explor.), 56, 439–451, 2003 (in Japanese with English abstract).

    Google Scholar 

  • Hyndmann, R. D., K. Wang, and M. Yamano, Thermal constraints on the seismogenic portion of the southwestern Japan subduction thrust, J. Geophys. Res., 100, 15373–15392, 1995.

    Article  Google Scholar 

  • Kasaya, T., S. Yamaguchi, T. Goto, M. Uyeshima, H. Utada, T. Kagiyama, H. Mikada, and K. Suyehiro, Exploration of a deep resistivity structure below the Kii Peninsula, SW Japan, Butsuri Tansa (Geophys. Explor.), 56, 427–437, 2003 (in Japanese with English abstract)..

    Google Scholar 

  • Kikuchi, M., M. Nakamura, and K. Yoshikawa, Source rupture processes of the 1944 Tonankai earthquake and the 1945 Mikawa earthquake derived from low-gain seismograms, Earth Planets Space, 55, 159–172, 2003.

    Article  Google Scholar 

  • Nakanishi, A., H. Shiobara, R. Hino, S. Kodaira, T. Kanazawa, and H. Shimamura, Detailed subduction structure across the eastern Nankai Trough obtained from ocean bottom seismographic profiles, J. Geophys. Res., 107, 27151–27168, 1998.

    Article  Google Scholar 

  • Nakanishi, A., N. Takahashi, J. O. Park, S. Miura, S. Kodaira, Y. Kaneda, N. Hirata, T. Iwasaki, and Masao Nakamura, Crustal structure across the coseismic rupture zone of the 1944 Tonankai earthquake, the central Nankai Trough seismogenic zone, J. Geophys. Res., 107, 10.129/2001JB000424, 2002.

  • Park, O. J., T. Tsuru, S. Kodaira, P. R. Cummins, and Y. Kaneda, Splay fault branching along the Nankai subduction zone., Science, 297, 1157–1160, 2002.

    Article  Google Scholar 

  • Ting, S. C. and G. W. Hohmann, Integral equation modeling of three dimensional magnetotelluric response, Geophysics, 46, 192–197, 1981.

    Article  Google Scholar 

  • Uchida, T. and T. Ogawa, Development of fortran code for twodimensional magnetotelluric inversion with smoothness constraint, Geological Survey of Japan Open-File Report, 205, 115 pp., 1993.

  • Ulmer, P. and V. Trommsdorff, Serpentine stability to mangle depths and subduction-related magmatism, Science, 268, 858–861, 1995.

    Article  Google Scholar 

  • Uyeshima, M., H. Utada, Y. Nishida, network-MT method and its first results in central and eastern Hokkaido, NE Japan, Geophys. J. Int., 146, 1–19, 2001.

    Article  Google Scholar 

  • Wannamaker, P. E., J. R. Booker, A. G. Jones, A. D. Chave, J. H. Filloux, H. S. Waff, and L. K. Law, Resistivity cross section through the Juan de Fuca subduction system and its tectonic implications, J. Geophys. Res., 94, 14127–14144, 1989.

    Article  Google Scholar 

  • Yamaguchi, S., Y. Kobayashi, N. Oshiman, K. Tanimoto, H. Murakami, I. Shiozaki, M. Uyeshima, H. Utada, and N. Sumitomo, Preliminary report on regional resistivity variation inferred from the Network MT investigation in the Shikoku district, southwestern Japan, Earth Planets Space, 51, 193–203, 1999.

    Article  Google Scholar 

  • Yamasaki, T. and T. Seno, Double seismic zone and dehydration embrittlement of the subducting slab, J. Geophys. Res., 108, 10.129/2002JB001918, 2003.

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Takafumi Kasaya.

Rights and permissions

Open Access  This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Kasaya, T., Goto, Tn., Mikada, H. et al. Resistivity image of the Philippine Sea Plate around the 1944 Tonankai earthquake zone deduced by Marine and Land MT surveys. Earth Planet Sp 57, 209–213 (2005). https://doi.org/10.1186/BF03351817

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03351817

Key words

  • Nankai trough
  • 1944 Tonankai earthquake
  • Magneto-telluric
  • OBEM
  • Resistivity
  • Conductor
  • Fluid
  • Kii Peninsula