Tutorials for CDM2024

[baagaard-usgs]

Tutorials

1. Introduction to PyLith v4.1
2. Static without faults: reverse-2d
   1. meshing (Gmsh)
   2. gravity (Step 1a,b,c)
   3. surface loading (Step 4)
3. Quasi-static with prescribed slip: reverse-2d
   1. one fault (Step 5a,b,c)
   2. two faults with different origin times (Step 6)
4. troubleshooting-2d
5. Advanced meshing with Gmsh
   1. 2D with nonplanar embedded fault crustal-strikeslip-2d
   2. 3D with nonplanar embedded fault crustal-strikeslip-3d
6. Quasi-static with prescribed slip: subduction-2d
   1. Interseismic (Step 2)
   2. Eq cycle with prescribed slip (Step 3)
7. Static Green's functions: strikeslip-2d
   1. Variable slip (Step 4)
   2. Green's functions (Step 5)
   3. Inversion (Step 6)
8. Numerical modeling 101 (Fri morning)

To-do

Update examples

For each example, make sure we cover:

1. Goal (physics)
2. Orientation (context)
3. Setup (what is needed)
4. Instructions
5. Validation (verify results)

• Convert box-3d Cubit scripts to Python
• Convert strikeslip-2d Cubit scripts to Python
• Convert reverse-2d Cubit scripts to Python
• Convert subduction-2d Cubit scripts to Python
• Merge 2D crustal fault example from 2023 hackathon (solution figures)
• Merge 3D crustal fault examples from 2023 hackathon (solution figures)
• Merge Daniel Douglas' outerrise poroelasticity example
• Finish migrating subduction-3d/step06 slow slip (solution figure)
• Finish migrating subduction-3d/step07a,b Green's functions (solution figure)
• Finish migrating subduction-3d/step08a,b,c gravity (solution figure)
• Add pylith_viz section to manual (utilities)
• Remove ParaView Python scripts from repo
• Update example docs to use pylith_viz
• Update reverse-2d example to start with coarse mesh (use refinement and basis order 2)
• Update reverse-2d (two faults with different origin times)
• Update strikeslip-2d example to start with coarse mesh (use refinement and basis order 2)
• Create Gmsh topography example (after tutorials are done)

Tutorial slides

• New slides for reverse-2d (meshing, gravity, surface loading) and discretization steps
• New or updated slides for reverse-2d (one fault, two faults with different origin times)
• Update slides for troubleshooting
• New slides for advanced meshing
• New slides for quasi-static with prescribed slip (interseismic and eq cycle)
• Update slides for static Green's functions

Record tutorials

• reverse-2d
• troubleshooting
• advanced meshing

[baagaard-usgs]

Terrain meshing: https://gitlab.onelab.info/gmsh/gmsh/blob/gmsh_4_12_2/tutorials/python/x2.py

Proposed workflow

1. Download elevation model as GeoTiff
2. Create STL file
   1. Use GDAL gdal.Translate() to get subset and convert to netCDF.
   2. Use netCDF4 to get coordinates of points
   3. Reshape to array of points
   4. Transform points to model CRS
   5. Triangulate using class scipy.spatial.Delaunay(points, furthest_site=False, incremental=False, qhull_options=None)
   6. Use numpy-stl to write STL file
3. Create geometry in Gmesh
   1. Create block in Gmsh using occ
   2. Create topographic surface using STL file
   3. Cut off top of block using surface

[baagaard-usgs]

PyVista notes

Mesh Quality

Slide widget for selecting threshold in mesh quality.

Checkbox widget for selecting component.

PyVista To-do

• WarpDisp: Time slider
• WarpDisp: Key bindings for time (<=prev, >=next)
• Fault slip / traction change component (or magnitude)
• Stress/strain component
• Allow multiple data files (same type) [maybe]