Free surface in geodynamics simulations
Geodynamic simulations increasingly rely on models with a true free surface to investigate questions of tectonic deformation, mantle convection, and coupling of surface processes and lithosphere dynamics. Historically, most mantle convection simulations have been performed with free-slip boundary conditions at the surface. However, the Earth's surface is a free surface, which implies that both normal and shear stress should be zero at this interface. Moreover, it has been shown that treating the Earth's surface as a free surface can have a significant effect on lithospheric and mantle dynamics (Schmeling et al., 2008; Kaus et al., 2010).
This is a companion discussion topic for the original entry at https://www.underworldcode.org/articles/free-surface-in-underworld/