Nonlinear pressure and temperature waves propagation in fluid-saturated rocks

A numerical study for the simulation of rock deformation due to nonlinear temperature and pressure waves in fluid saturated porous rock is presented. The problem of an homogeneous, thermoelastic, and isotropic fluid-saturated matrix, lying over an aquifer in hyperthermal domain an limited by an upper free surface is considered. The equations of thermo-poro-elasticity, the energy balance and Darcy equation are employed to model the deformation induced by pressure and temperature gradients originating from the source at depth. The numerical approach adopted to solve the nonlinear problem is based on a cubic finite-element method for the spatial discretization and an implicit scheme for the temporal discretization. This work essentially provides a numerical tool for interpreting some geophysical phenomena, in particular for the study of ground uplift in volcanic areas such as Rabaul caldera, Long Valley caldera, and Campi Flegrei. Some experiments and results are presented.