A free surface capturing discretization for the staggered grid finite difference scheme
Abstract
The coupling that exists between surface processes and deformation within both the shallow
crust and the deeper mantle-lithosphere has stimulated the development of computational
geodynamic models that incorporate a free surface boundary condition. We introduce a treatment
of this boundary condition that is suitable for staggered grid, finite difference schemes
employing a structured Eulerian mesh. Our interface capturing treatment discretizes the free
surface boundary condition via an interface that conforms with the edges of control volumes
(e.g. a ‘staircase’ representation) and requires only local stencil modifications to be performed.
Comparisons with analytic solutions verify that the method is first-order accurate. Additional
intermodel comparisons are performed between known reference models to further validate
our free surface approximation. Lastly, we demonstrate the applicability of a multigrid solver
to our free surface methodology and demonstrate that the local stencil modifications do not
strongly influence the convergence of the iterative solver.
Origin : Publisher files allowed on an open archive
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