地震波の減衰がS 波偏向異方性に及ぼす影響

We investigate the effect of the seismic attenuation on the shear-wave polarization anisotropy by numerical experiments. For the experiments, the P-wave receiver functions are synthesized by assuming that a plane P wave is incident on an anisotropic multi-layer structure with anelastic properties. The synthetic receiver function shows smooth Ps phase waveforms with small amplitudes due to the attenuation of high-frequency spectral components, compared to that calculated for a multi-layer structure with perfect elasticity. From the shear-wave splitting of the Ps converted phases in the synthetic receiver functions, the S-wave polarization anisotropies for the anisotropic layers are measured as a function of propagation direction of the incident P wave. Consequently, we conclude that the seismic attenuation has a minor influence on the measurements of the S-wave polarization anisotropy.