Simulation of tectonic plates subduction with a multi-phase X-FEM model: level set representation, functional enrichment and numerical integration

A numerical model for plate tectonic subduction is presented. The subduction system behaves mechanically as a multiphase fluid governed by the Stokes equation. In the limit of creeping flow or the zero Reynolds number regime, the Stokes equation becomes a highly non-linear partial differential equation primarily because of non-linear constitutive relationship between the stress and strain-rate tensors. This mechanical problem is highly coupled with a thermal problem. The physical properties of the rocks (density, thermal conductivity, viscosity, etc.) are function of the temperature and pressure.