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Volume 56 Supplement 12

Special Issue: Slip and Flow Processes in and below the Seismogenic Region (2)

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Rock microstructure in the deep extension of the Nagamachi-Rifu fault revealed by analysis of collocated seismic and magnetotelluric data: Implication of strong deformation process

Abstract

Quantitative analysis of collocated seismic velocity tomography and electromagnetic experiments is developed to elucidate the structure of the deep extension of the Nagamachi-Rifu fault, northeastern Japan. P and S wave seismic velocities obtained from a dense seismic network are examined and a ratio of spatial variation in P and S wave velocities d ln V s /d ln V p is chosen as a proxy for the influence of pore geometry. The analysis shows that the deep extension of the Nagamachi-Rifu fault reveals the d ln V s /d ln V p values exceeded 1.1. Such large values of d ln V s /d ln V p cannot correspond to equilibrium pore geometry, at which the interfacial energy is at a minimum, and indicate regions with non-equilibrium state where non-isotropic stress prevents the equilibrium pore geometry to be achieved. To specify a fine distribution of porosity and connectivity of micropore in the region, we carry out the joint analysis of the seismic velocities with the electrical resistivity data obtained by the magnetotelluric survey crossing the Nagamachi-Rifu fault. It is shown that the region at 10–17 km depths at about 20–40 km to the northwest from the hypocenter of the M5.0 earthquake occurred in 1998 exposes the highest connectivity among the adjacent areas, suggesting a strong deformation process.

References

  • Ahrens, T. J. (ed.), Mineral Physics and Crystallography. A Handbook of Physical Constants, American Geophysical Union, 354 pp., 2000.

    Google Scholar 

  • Clark, S. P. (ed.), Handbook of Physical Constants, The Geological Society of America, 589 pp., 1966.

    Google Scholar 

  • Hyndman, R. D. and P. M. Shearer, Water in the lower continental crust: Modeling magnetotelluric and seismic reflection results, Geophys. J. Int., 98, 343–365, 1989.

    Article  Google Scholar 

  • Iio, Y., A possible generating process of the 1995 Southern Hyogo Prefecture earthquake, J. Seism. Soc. Japan, 49, 103–112, 1996 (in Japanese with English abstract).

    Google Scholar 

  • Iio, Y. and Y. Kobayashi, A physiscal understanding of large intraplate earthquakes, Earth Planets Space, 54(11), 1001–1004, 2002.

    Article  Google Scholar 

  • Imanishi, K., H. Ito, Y. Kuwahara, Y. Mamada, T. Yokokura, N. Kano, K. Yamaguchi, and A. Tanaka, Deep structure of the Nagamachi-Rifu fault from small aperture seismic array observations, Earth Planets Space, 54(11), 1033–1038, 2002.

    Article  Google Scholar 

  • Jones, A. G., Waves of the future: Superior inferences from collocated seismic and electromagnetic experiments, Tectonophysics, 286, 273–298, 1998.

    Article  Google Scholar 

  • Kennett, B. L. N., S. Widiyantoro, and R. D. van der Hilst, Joint seismic tomography for bulk sound and shear wave speed in the Earth’s mantle, J. Geophys. Res., 103(B6), 12,469–12,493, 1998.

    Article  Google Scholar 

  • Masters, G., G. Laske, H. Bolton, and A. Dziewonski, The relative behavior of shear velocity, bulk sound speed, and compressional velocity in the mantle: Implications for chemical and thermal structure, in Earth’s Deep Interior: Mineral Physics and Tomography from the Atomic to the Global Scale, Geophys. Monogr. Ser., vol. 117, edited by S. Karato et al., pp. 63–87, AGU, Washington D. C., 2000.

    Chapter  Google Scholar 

  • Nakajima, J., Temperature and fluid distributions in the northeastern Japan arc inferred from seismic velocity and anisotropy structures, Doctoral dissertation, Tohoku University, Sendai, Japan, 146 pp., 2002 (in Japanese).

    Google Scholar 

  • Nakajima, J., A. Hasegawa, S. Horiuchi, K. Yoshimoto, T. Yoshida, and N. Umino, Crustal heterogeneity around the Nagamachi-Rifu fault, northeastern Japan, as inferred from travel-time tomography, Earth Planets Space, 2004 (submitted).

    Google Scholar 

  • Nakamura, A., Y. Asano, and A. Hasegawa, Estimation of deep fault geometry of the Nagamachi-Rifu fault from seismic array observations, Earth Planets Space, 54(11), 1027–1032, 2002.

    Article  Google Scholar 

  • Nishimura, T., T. Sagiya, and S. Miura, Crustal deformation around the Nagamachi-Rifu fault zone and its vicinity (central Tohoku), northeastern Japan, observed by a continuous GPS network, Zisin (J. Seismol. Soc. Jpn.), 56(4), 2004 (in Japanese).

    Google Scholar 

  • Ogawa, Y., M. Mishina, Y. Honkura, K. Takahashi, and S. B. Tank, Electromagnetic Imaging of the Nagamachi-Rifu Fault and Its Deep Extension, The Second International Symposium on Slip and Flow Processes in and below the Seismogenic Region, 2004.

    Google Scholar 

  • Pervukhina, M., Y. Kuwahara, and H. Ito, Modelling of elastic and electrical properties of dry and saturated rock. XXIII General Assembly of International Union of Geodesy and Geophysics, June 30–July 11, Sapporo, Japan, 2003.

    Google Scholar 

  • Pervukhina, M., Y. Kuwahara, and H. Ito, Fractal network and mixture models for elastic and electrical properties of porous rock, in Fractal Behavior of the Earth System, Springer Verlag Publisher, Germany, 2004 (accepted).

    Google Scholar 

  • Sato, H., T. Imaizumi, T. Yoshida, H. Ito, and A. Hasegawa, Tectonic evolution and deep to shallow geometry of Nagamachi-Rifu Active Fault System, NE Japan, Earth Planets Space, 54(11), 1039–1043, 2002.

    Article  Google Scholar 

  • Simpson, F. and M. Warner, Coincident magnetotelluric, P-wave and Swave images of the deep continental crust beneath the Weardale granite, NE England: Seismic layering, low conductance and implications against the fluids paradigm, Geophys. J. Int., 133, 419–434, 1998.

    Article  Google Scholar 

  • Spangenberg, E., A fractal model for physical properties of porous rock: Theoretical formulations and applications, J. Geophys. Res., 103(B6), 12,269–12,289, 1998.

    Article  Google Scholar 

  • Takei, Y., Constitutive mechanical relations of solid-liquid composites in terms of grain-boundary contiguity, J. Geophys. Res., 103, 18,183–18,203, 1998.

    Article  Google Scholar 

  • Takei, Y., Effect of pore geometry on Vp/Vs: From equilibrium geometry to crack, J. Geophys. Res., 107(B2), 10.1029/2001JB000522, 20

  • Tanaka, A. and Y. Ishikawa, Temperature distribution and focal depth of NE Japan, Earth Planets Space, 54(11), 1109–1113, 2002.

    Article  Google Scholar 

  • Umino, N., H. Ujikawa, S. Hori, and A. Hasegawa, Distinct S-wave reflectors (bright sports) detected beneath the Nagamachi-Rifu fault, NE Japan, Earth Planets Space, 54(11), 1021–1026, 2002.

    Article  Google Scholar 

  • Watson, E. B. and J. M. Brenan, Fluids in lithosphere, 1. Experimentally determined wetting characteristics of CO2−H2O fluids and their implications for fluid transport, host-rock physical properties, and fluid inclusion formation, Earth and Planetary Science Letters, 85, 497–515, 1987.

    Article  Google Scholar 

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Correspondence to Marina Pervukhina.

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Pervukhina, M., Kuwahara, Y. & Ito, H. Rock microstructure in the deep extension of the Nagamachi-Rifu fault revealed by analysis of collocated seismic and magnetotelluric data: Implication of strong deformation process. Earth Planet Sp 56, 1357–1368 (2004). https://doi.org/10.1186/BF03353361

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  • DOI: https://doi.org/10.1186/BF03353361

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