Development of New Features for the PyLith Finite Element Code to Enable Innovative Research In Multiple Earthquake Cycle Simulations

这笔资金将用于支持一项为期两年的工作，以开发现有PyLith 1.0版地壳动力学建模包的代码增强。PyLith目前由NSF/EAR支持的地球动力学计算基础设施（Computational Infrastructure for Geodynamics， CIG）设施维护和支持，但这种支持解决了CIG目前没有针对的代码增强问题。增强将包括：1)准静态和动态解的耦合，允许完整模拟地震周期，包括动态破裂过程；2)开发非线性求解器，模拟真实的地壳材料行为（如粘弹性、弹塑性、弹粘塑性）；3)重力预应力自动计算；4)发展使用球面网格有限元框架建模大空间区域动力学的能力。这项工作将涉及与CIG资助人员（Matt Knepley， Argonne国家实验室），美国地质勘测局（Brad Aagaard）和加州理工学院博士生的免费合作。代码开发将是开源的，并在CIG存储库中进行维护。

Funding from this grant will support a two-year effort to develop code enhancements to the existing PyLith version 1.0 crustal dynamics modeling package. PyLith is currently maintained and supported through the NSF/EAR supported Computational Infrastructure for Geodynamics (CIG) facility but this support addresses code enhancements not currently targeted by CIG for future development. Enhancements will include: 1) coupling of quasi-static and dynamic solutions to allow for complete simulation of the earthquake cycle, including the dynamic rupture process; 2) development of nonlinear solvers to enable simulation of realistic crustal material behavior (e.g., viscoelastic, elastoplastic, elasto-viscoplastic); 3) automatic computation of gravitational prestresses; and 4) development of the capability to use a spherical mesh finite element framework for modeling the dynamics of large spatial areas. The work will involve no-cost collaborations with CIG funded personnel (Matt Knepley, Argonne National Lab), the USGS (Brad Aagaard) and a Caltech Ph.D. student. The code developments will be open-source and maintained in the CIG repository.