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  • Letter
  • Open Access

Shear wave polarization anisotropy in and around the focal region of the 2005 West off Fukuoka Prefecture earthquake

Earth, Planets and Space200758:BF03352674

https://doi.org/10.1186/BF03352674

  • Received: 15 October 2005
  • Accepted: 22 June 2006
  • Published:

Abstract

Crustal shear wave polarization anisotropy is caused by the alignment of vertical microcracks. Leading shear wave polarization directions (LSPDs) are presumed to be consistent with the maximum horizontal compressional axis in many cases. We analyzed shear wave polarization anisotropy in and around the focal region of the 2005 West off Fukuoka Prefecture earthquake. Almost all of the LSPDs are oriented in the E-W direction, which is consistent with the maximum horizontal compressional axis inferred from the mechanism of the main shock. These E-to W-oriented LSPDs are caused by the alignment of stress-induced microcracks. Crack densities at most stations are estimated to be 0.02. Little spacial stress variation around focal region is suspected

Key words

  • Shear wave polarization anisotropy
  • 2005 West off Fukuoka earthquake

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