Seismic Anisotropy
Seismic Anisotropy : A term used for effective material parameters which depend on the direction of propagation or polarization of seismic waves. It includes isotropic media with aligned small-scale heterogeneities that may behave anisotropic for seismic wavelengths longer than the heterogeneity scale. See Curtis and Snieder (2002), and Cara (2002)