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Mantle and crust anisotropy in the eastern China region inferred from waveform splitting of SKS and PpSms

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Abstract

S-waves converted from P-waveat different boundaries inside the earth, i.e., the Moho discontinuity and CMB, are used to determine the distribution of anisotropy in different layers. A clear later phase at approximately 17 sec after the direct P-wave, which is identified to be PpSms (a phase that is P-to-S converted at the free surface and is reflected by the Moho discontinuity on the receiver side), is observed in the radial component of seismograms recorded by broadband stations in the east China region. Waveform splitting observed from the PpSms and SKS suggests that the crust beneath the eastmost part of China is almost isotropic, and the mantle is weakly anisotropic. Splitting analysis using converted waves is a promising technique for investigating the depth distribution of shear-wave splitting.

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Correspondence to Takashi Iidaka.

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Keywords

  • Seismic Station
  • Lower Mantle
  • Seismic Anisotropy
  • Converted Wave
  • Fast Polarization