Earth, Planets and Space

, Volume 55, Issue 5, pp 277–282 | Cite as

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

Open Access


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.

Key words

Shear-wave splitting southwest Japan later phase anisotropy 


  1. 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
  2. Bath, M. and R. Stefansson, S-P conversion at the base of the crust, Annali di Geofisica, 19, 119–130, 1966.Google Scholar
  3. Cerveny, V. and I. Psencik, Program Package SEIS83, 1983.Google Scholar
  4. Crampin, S., A review of wave motion in anisotropic and cracked elastic-medium, Wave Motion, 3, 343–391, 1981.CrossRefGoogle Scholar
  5. Fukao, Y., Evidence from core-reflected shear waves anisotropy in the Earth’s mantle, Nature, 309, 695–698, 1984.CrossRefGoogle Scholar
  6. Haskell, N. A., Crustal reflections of the plane P and SV waves, J. Geophys. Res., 67, 4751–4767, 1962.CrossRefGoogle Scholar
  7. 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.CrossRefGoogle Scholar
  8. 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.CrossRefGoogle Scholar
  9. Iidaka, T. and K. Obara, Shear-wave polarization anisotropy in the mantle wedge above the subducting Pacific plate, Tectonophys., 249, 53–68, 1995.CrossRefGoogle Scholar
  10. 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.CrossRefGoogle Scholar
  11. Iwamori, H., Zonal structure of Cenozoic basalts related to mantle upwelling in southwest Japan, J. Geophys. Res., 96, 6157–6170, 1991.CrossRefGoogle Scholar
  12. 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.Google Scholar
  13. Kaneshima, S., Original of crustal anisotropy: Shear wave splitting studies in Japan, J. Geophys. Res., 95, 11121–11133, 1990.CrossRefGoogle Scholar
  14. Marson-Pidgeon, K. and M. Savage, Frequency-dependent anisotropy in Wellington, New Zealand, Geophys. Res. Lett., 24, 3297–3300, 1997.CrossRefGoogle Scholar
  15. 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
  16. 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.CrossRefGoogle Scholar
  17. Otofuji, Y. and T. Matsuda, Paleomagnetic evidence for the clockwise rotation of Southwest Japan, Earth Planet. Sci. Lett., 62, 349–359, 1983.CrossRefGoogle Scholar
  18. Park, J. and V. Levin, Seismic anisotropy: tracing plate dynamics in the mantle, Science, 296, 485–489, 2002.CrossRefGoogle Scholar
  19. Silver, P. G., Seismic anisotropy beneath the continents: Probing the depths of geology, Annu. Rev. Earth Planet. Sci., 24, 385–432, 1996.CrossRefGoogle Scholar
  20. Silver, P. G. and W. Chan, Shear wave splitting and subcontinental mantle deformation, J. Geophys. Res., 96, 16429–16454, 1991.CrossRefGoogle Scholar
  21. Tsukahara, H. and Y. Kobayashi, Crustal stress in the central and western parts of Honshu, Japan, Zisin, 44, 221–231, 1991.Google Scholar
  22. Tsuruoka, H., Development of earthquake information retrieval and analysis system on WWW, I.PS.J. SIG Notes, 98, 65–70, 1998.Google Scholar
  23. 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.CrossRefGoogle Scholar

Copyright information

© The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences. 2003

Authors and Affiliations

  1. 1.Earthquake Research InstituteUniversity of TokyoTokyoJapan

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