f Anisotropic attenuation of fine layering, fluid-filled fracture systems and layered porous media

A stack of fine, plane and parallel layers constitutes an useful system for studying the wave propagation characteristics of basic geological and rock structures. In a previous paper (Carcione, 1991 ), the model was used to study the anisotropic-attenuation characteristics of waves propagation in a viscoelastic finely layered medium composed of two constituents . As is well known, when the thicknesses of the component layers are much smaller than the wavelength of the seismic pulse, a stratified medium can be replaced by an equivalent homogeneous transversely-isotropic medium . For a viscoelastic system, the complex stiffness matrix is given by Backus's equations through application of the correspondence principle. Carcione (1991) calculaled the energy velocities and quality factors of the three propagaling modes as a function of frequency and material proportions . He obtained in this way a model for describing anisotropic attenuation of fine Iayoring due to intrinsic loss mechanisms.