f Information content of amplitude versus offset of shear-waves in anisotropic media

Many recent publications (Alford 1986, Martin and Davis 1987, Squires et al 1989) have analyzed anisotropy in shear-wave reflection surveys. Such studies yield values of the percentage anisotropy over wide depth ranges in the shear-wave section. Percentage anisotropy is usually calculated from the time delays between the arrivals of the fast and slow split shear-waves and gives information about the crack density and porosity in the section. The polarization direction of the fast split shear-wave is determined by the crack and stress geometries in the rock and is Iikely to yield information about preferential directions of fluid flow within a reservoir.