PyLith v2.2.0

PyLith is an open-source finite-element code for dynamic and quasistatic simulations of crustal deformation, primarily earthquakes and volcanoes.

• Main page: [https://geodynamics.org/cig/software/pylith](https://geodynamics.org/cig/software/pylith)
  • User Manual
  • Binary packages
  • Utility to build PyLith and all of its dependencies from source
• PyLith Wiki: [https://wiki.geodynamics.org/software:pylith:start](https://wiki.geodynamics.org/software:pylith:start)
  • Archive of online tutorials
  • Hints, tips, tricks, etc
  • PyLith development plan 
• Submit bug reports via https://github.com/geodynamics/pylith/issues
• Send all questions to: cig-short@geodynamics.org

Features

• Quasi-static (implicit) and dynamic (explicit) time-stepping
• Cell types include triangles, quadrilaterals, hexahedra, and tetrahedra
• Linear elastic, linear and generalized Maxwell viscoelastic, power-law viscoelastic, and Drucker-Prager elastoplastic materials
• Infinitesimal and small strain elasticity formulations
• Fault interfaces using cohesive cells
  • Prescribed slip with multiple, potentially overlapping earthquake ruptures and aseismic creep
  • Spontaneous slip with slip-weakening friction and Dieterich rate- and state-friction fault constitutive models
• Time-dependent Dirichlet (displacement/velocity) boundary conditions
• Time-dependent Neumann (traction) boundary conditions
• Time-dependent point forces
• Absorbing boundary conditions
• Gravitational body forces
• VTK and HDF5/Xdmf output of solution, fault information, and state variables
• Templates for adding your own bulk rheologies, fault constitutive models, and interfacing with a custom seismic velocity model.
• User-friendly computation of static 3-D Green's functions

Installation

Detailed installation instructions for the binary packages are in the User Manual with detailed building instructions for a few platforms in the INSTALL file bundled with the PyLith Installer utility. We also offer a Docker image (https://wiki.geodynamics.org/software:pylith:docker) for running PyLith within a portable, virtual Linux environment.

Release Notes

• Added a browser-based parameter viewer for interactive viewing of all PyLith parameters and version information. See Section 4.10 PyLith Parameter Viewer of the PyLith user manual.

• Adjusted packaging of the binary distributions so that they can be used to extend PyLith and/or integrate other code with PyLith.

• Converted the user manual from Lyx to LaTeX and added syntax highlighting of parameter and spatial database files. Fixed several typos.

• Fixed bug that sometimes resulted in an inconsistent fault orientation when running in parallel. The bug appears to have been introduced in v2.0.

• Fixed two bugs in output of solution at points that sometimes happened in parallel simulations. The errors include:

  • The order of the station names does not match the order of the points. The point data is written in parallel by process order, so the points for process 0 are written first, then those for process 1, etc. This often results in reordering of the points. The station names were written in the original order.

  • The output values for some points are incorrect. The wrong cells were being used in the interpolation.

• Updated PETSc to v3.7.5.