Common Information

In addition to the finite-element mesh, PyLith requires files to specify the simulation parameters. We specify parameters common to all simulations in a directory in pylithapp.cfg, which contains numerous comments, so we only summarize the parameters here.

The settings contained in pylithapp.cfg for this problem consist of:

• pylithapp.metadata Metadata common to all of the simulations in the directory.

• pylithapp.journal.info Parameters that control the verbosity of the output written to stdout for the different components.

• pylithapp.mesh_generator Parameters for importing the finite-element mesh.

• pylithapp.problem Parameters that define the boundary value problem and its solution, such as the type of solver, solution fields, and output over the domain.

• pylithapp.problem.materials Parameters that specify the governing equation and bulk rheologies.

• pylithapp.problem.bc Parameters that specify the boundary conditions.

To make it easier to switch between different bulk rheologies for different simulations, we separate the material parameters relevant to the bulk rheologies into three parameter files: mat_elastic.cfg, mat_viscoelastic.cfg, and mat_elastic_incompressible.cfg. We use mat_elastic.cfg when we want all materials to use elastic bulk rheologies. We use mat_viscoelastic.cfg when we want the mantle and bottom of the slab to use viscoelastic bulk rheologies. We use mat_elastic_incompressible.cfg only for Step 8b in which we use incompressible elasticity. The physical properties for each material are specified in spatial database files. For example, the elastic properties for the crust are in mat_crust_elastic.spatialdb. The spatial database files for elastic properties all use just a single point to specify uniform physical properties within each material.