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Shear-wave splitting analysis of later phases in southwest Japan —A lineament structure detector inside the crust—

Abstract

We attempt to detect the lineament structure inside the crust using a shear-wave splitting analysis. A seismicity map suggests several lineaments in southwest Japan. No clear active fault was found to support the lineaments. We researched shear-wave splitting in southwest Japan using two later phases: PpPms and PpSms. The PpPms is a later S-phase, which is reflected at the surface as a P wave, dives again, and reflected and converted from P to S at the Moho boundary. The PpSms is a later arriving S-phase, which is converted from P at the Earth’s surface, and is reflected at the Moho discontinuity before arriving at a seismic station. The PpPms and PpSms phases are used to detect lineament structures inside the crust. The observed polarization directions obtained are ENE-WSW, NE-SW, and N-S with a lateral variation. The directions are not consistent with that of maximum principal stress in the area. The results of shear-wave splitting in southwest Japan could not be explained by crack-induced anisotropy caused by maximum principal stress. The direction NE-SW is consistent with that of the geological lineament structure in this area. The shear-wave splitting is probably caused by the lineament structure inside the crust.

References

  • Ando, M., The stress field of the Japan Islands in the last 0.5 million years, Earth Mon. Symp., 7, 541–546, 1979.

    Google Scholar 

  • Bath, M. and R. Stefansson, S-P conversion at the base of the crust, Annali di Geofisica, 19, 119–130, 1966.

    Google Scholar 

  • Cerveny, V. and I. Psencik, Program Package SEIS83, 1983.

  • Crampin, S., A review of wave motion in anisotropic and cracked elastic-medium, Wave Motion, 3, 343–391, 1981.

    Article  Google Scholar 

  • Fukao, Y., Evidence from core-reflected shear waves anisotropy in the Earth’s mantle, Nature, 309, 695–698, 1984.

    Article  Google Scholar 

  • Haskell, N. A., Crustal reflections of the plane P and SV waves, J. Geophys. Res., 67, 4751–4767, 1962.

    Article  Google Scholar 

  • Hiramatsu, Y., M. Ando, T. Tsukuda, and T. Ooida, Three-dimensional image of the anisotropic bodies beneath central Honshu, Japan, Geophys. J. Int., 135, 801–816, 1998.

    Article  Google Scholar 

  • Iidaka, T. and F. Niu, Mantle and crustal anisotropy in the eastern China region inferred from waveform splitting of SKS and PpSms, Earth Planets Space, 53, 159–168, 2001.

    Article  Google Scholar 

  • Iidaka, T. and K. Obara, Shear-wave polarization anisotropy in the mantle wedge above the subducting Pacific plate, Tectonophys., 249, 53–68, 1995.

    Article  Google Scholar 

  • Isozaki, Y. and S. Maruyama, Studies on orogeny based on plate tectonics in Japan and new geotectonic subdivision of the Japanese Islands, Journal of Geography, 100, 697–761, 1991.

    Article  Google Scholar 

  • Iwamori, H., Zonal structure of Cenozoic basalts related to mantle upwelling in southwest Japan, J. Geophys. Res., 96, 6157–6170, 1991.

    Article  Google Scholar 

  • Japanese University Group of the Joint Seismic Observations at the Southwestern Japan, The joint seismic observations at the southwestern Japan, Abst. Seismo. Soc. Japan Fall Meeting, P004, 2002.

  • Kaneshima, S., Original of crustal anisotropy: Shear wave splitting studies in Japan, J. Geophys. Res., 95, 11121–11133, 1990.

    Article  Google Scholar 

  • Marson-Pidgeon, K. and M. Savage, Frequency-dependent anisotropy in Wellington, New Zealand, Geophys. Res. Lett., 24, 3297–3300, 1997.

    Article  Google Scholar 

  • Nakamura, M., H. Watanabe, T. Konomi, S. Kimura, and K. Miura, Characteristic activities of subcrustal earthquakes along the outer zone of southwestern Japan, Annuals of Disas. Prev. Res. Inst., Kyoto Univ., 40, 1–20, 1997.

    Google Scholar 

  • Niu, F. and D. James, Fine structure of the lowermost crust beneath the Kaapvaal craton and its implications for crustal formation and evolution, Earth and Planet. Sci. Lett., 200, 121–130, 2002.

    Article  Google Scholar 

  • Otofuji, Y. and T. Matsuda, Paleomagnetic evidence for the clockwise rotation of Southwest Japan, Earth Planet. Sci. Lett., 62, 349–359, 1983.

    Article  Google Scholar 

  • Park, J. and V. Levin, Seismic anisotropy: tracing plate dynamics in the mantle, Science, 296, 485–489, 2002.

    Article  Google Scholar 

  • Silver, P. G., Seismic anisotropy beneath the continents: Probing the depths of geology, Annu. Rev. Earth Planet. Sci., 24, 385–432, 1996.

    Article  Google Scholar 

  • Silver, P. G. and W. Chan, Shear wave splitting and subcontinental mantle deformation, J. Geophys. Res., 96, 16429–16454, 1991.

    Article  Google Scholar 

  • Tsukahara, H. and Y. Kobayashi, Crustal stress in the central and western parts of Honshu, Japan, Zisin, 44, 221–231, 1991.

    Google Scholar 

  • Tsuruoka, H., Development of earthquake information retrieval and analysis system on WWW, I.PS.J. SIG Notes, 98, 65–70, 1998.

    Google Scholar 

  • Yoshii, T., Y. Sasaki, T. Tada, H. Okada, S. Asano, I. Muramatsu, M. Hashizume, and T. Moriya, The third Kurayoshi explosion and the crustal structure in the western part of Japan, J. Phys. Earth, 22, 109–121, 1974.

    Article  Google Scholar 

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Correspondence to Takashi Iidaka.

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Iidaka, T. Shear-wave splitting analysis of later phases in southwest Japan —A lineament structure detector inside the crust—. Earth Planet Sp 55, 277–282 (2003). https://doi.org/10.1186/BF03351760

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