Computational Analysis of Seismic Waves Attenuation Caused by Porosity Variability in a Fluid-Saturated Porous Model of Thawing Permafrost

A computational model for wave fields simulation in a saturated deformable porous medium is presented. The governing differential equations of the model are derived from a general Symmetric Hyperbolic Thermodynamically Compatible (SHTC) two-phase model of saturated porous medium and form a linear PDE system allowing the application of an efficient finite difference method on a staggered grid. A series of numerical test problems showed a strong dependence of wave attenuation on porosity and relaxation time coefficient. It was also shown that the constitutive equations of the SHTC give a constant value of the quality factor over a range of seismic frequencies, making it possible to use the SHTC model to develop seismic methods for monitoring permafrost thaw.