A method for modeling deformation in subsurface strata, including defining physical boundaries for a geomechanical system. The method also includes acquiring one or more mechanical properties of the subsurface strata within the physical boundaries, and acquiring one or more thermal properties of the subsurface strata within the physical boundaries. The method also includes creating a computer-implemented finite element analysis program representing the geomechanical system and defining a plurality of nodes representing points in space, with each node being populated with at least one of each of the mechanical properties and the thermal properties. The program solves for in situ stress at selected nodes within the mesh.