Ongoing development of PyLith version 3: New features, additional examples, and current priorities

Brad T. Aagaard, Matthew G. Knepley, Charles A. Williams, & Robert L. Walker

Submitted September 10, 2023, SCEC Contribution #12810, 2023 SCEC Annual Meeting Poster #145

We give an overview of recently added features and examples along with future development priorities of the open-source crustal deformation modeling code PyLith. PyLith focuses on solving earthquake faulting-related partial differential equations, such as elasticity and poroelasticity, using a modular, multiphysics formulation in two and three dimensions, which was introduced in version 3.0.0 released in June 2022. Recent development has focused on (1) a more modular implementation of governing equations and the associated bulk rheologies, (2) implementation of prescribed fault slip for elastodynamics using the multiphysics formulation, and (3) integration of test infrastructure with the Visual Studio Code Integrated Development Environment to facilitate debugging unit tests, method of manufactured solutions tests, and full-scale tests. A hackathon in June 2023 helped accelerate or initiate contributions from community members for (1) re-implementation of spontaneous rupture with fault friction using the multiphysics formulation, (2) point sources for earthquakes and fluids, (3) self-gravitation, and (4) new example suites for two- and three-dimensional crustal faulting. Ongoing development priorities include leveraging Jupyter notebooks in the suite of examples, earthquake cycle modeling via coupling of quasistatic and dynamic problems, complex spatial and temporal specifications of boundary conditions, and a simplified approach for customizing governing equations and rheologies. PyLith is developed and distributed through the Computational Infrastructure for Geodynamics (https://geodynamics.org/resources/pylith) and includes source code, binary packages, online documentation (https://pylith.readthedocs.io), video tutorials, and a Docker container for software development.

Key Words
crustal deformation, software, quasistatic, dynamic

Citation
Aagaard, B. T., Knepley, M. G., Williams, C. A., & Walker, R. L. (2023, 09). Ongoing development of PyLith version 3: New features, additional examples, and current priorities . Poster Presentation at 2023 SCEC Annual Meeting.

Related Projects & Working Groups
Stress and Deformation Over Time (SDOT)