Abstract
Numerical simulations of Sequences of Earthquakes and Aseismic Slip (SEAS) have rapidly progressed to address fundamental problems in fault mechanics and provide self-consistent, physics-based frameworks to interpret and predict geophysical observations across spatial and temporal scales. To advance SEAS simulations with rigor and reproducibility, we pursue community efforts to verify numerical codes in an expanding suite of benchmarks. Here we present code comparison results from a new set of quasi-dynamic benchmark problems BP6-QD-A/S/C that consider an aseismic slip transient induced by changes in pore fluid pressure consistent with fluid injection and diffusion in fault models with different treatments of fault friction. Ten modeling groups participated in problems BP6-QD-A and BP6-QD-S considering rate-and-state fault models using the aging (-A) and slip (-S) law formulations for frictional state evolution, respectively, allowing us to better understand how various computational factors across codes affect the simulated evolution of pore pressure and aseismic slip. Comparisons of problems using the aging versus slip law, and a constant friction coefficient (-C), illustrate how aseismic slip models can differ in the timing and amount of slip achieved with different treatments of fault friction given the same perturbations in pore fluid pressure. We achieve excellent quantitative agreement across participating codes, with further agreement attained by ensuring sufficiently fine time-stepping and consistent treatment of boundary conditions. Our benchmark efforts offer a community-based example to reveal sensitivities of numerical modeling results, which is essential for advancing multi-physics SEAS models to better understand and construct reliable predictive models of fault dynamics.
| Original language | English |
|---|---|
| Article number | e2024JB030601 |
| Journal | Journal of Geophysical Research: Solid Earth |
| Volume | 130 |
| Issue number | 4 |
| Early online date | 2 Apr 2025 |
| DOIs | |
| Publication status | Published - Apr 2025 |
Bibliographical note
Publisher Copyright:© 2025. The Author(s).
Funding
V.L. and E.M.D. designed the benchmark problem with input from B.A.E. and J.J. V.L., B.A.E., and J.J. organized the workshops for code verification exercises. V.L. analyzed the simulation results and led the writing of the manuscript. All remaining authors provided feedback on benchmark design, participated in the benchmark exercises (listed in Table 1 ), and/or helped with revising the manuscript. T.K. additionally helped with tests of model convergence and time\u2010stepping; the other authors are listed alphabetically. V.L., B.A.E., and J.J. are supported by the Statewide California Earthquake Center (SCEC) awards 22079, 23144, and 24087. A SEAS\u2010themed workshop was funded by SCEC award 22123. This research is SCEC Contribution No.13455. SCEC is funded by the National Science Foundation (NSF) Cooperative Agreement EAR\u20101600087 and the United States Geological Survey (USGS) Cooperative Agreement G17AC00047. V.L. was also supported by a National Science Foundation Postdoctoral Fellowship. S.O. was funded from an oversea research fellowship of Japan Society for the Promotion of Science. P.R. was supported by the European Research Council (ERC) Starting Grants 101040600 (HYQUAKE). M.L. and Y.v.D. are supported by the Dutch Research Council (NWO) grant DEEP.NL.2018.037. E.M.D. was supported by National Science Foundation award EAR\u20101947448. Y.Y. is supported by the Research Grants Council Postdoctoral Fellowship, University Grants Committee, Hong Kong (PDFS2223\u20104S08) and the Faculty of Science at the Chinese University of Hong Kong. V.L. and E.M.D. designed the benchmark problem with input from B.A.E. and J.J. V.L., B.A.E., and J.J. organized the workshops for code verification exercises. V.L. analyzed the simulation results and led the writing of the manuscript. All remaining authors provided feedback on benchmark design, participated in the benchmark exercises (listed in Table\u00A01), and/or helped with revising the manuscript. T.K. additionally helped with tests of model convergence and time-stepping; the other authors are listed alphabetically. V.L., B.A.E., and J.J. are supported by the Statewide California Earthquake Center (SCEC) awards 22079, 23144, and 24087. A SEAS-themed workshop was funded by SCEC award 22123. This research is SCEC Contribution No.13455. SCEC is funded by the National Science Foundation (NSF) Cooperative Agreement EAR-1600087 and the United States Geological Survey (USGS) Cooperative Agreement G17AC00047. V.L. was also supported by a National Science Foundation Postdoctoral Fellowship. S.O. was funded from an oversea research fellowship of Japan Society for the Promotion of Science. P.R. was supported by the European Research Council (ERC) Starting Grants 101040600 (HYQUAKE). M.L. and Y.v.D. are supported by the Dutch Research Council (NWO) grant DEEP.NL.2018.037. E.M.D. was supported by National Science Foundation award EAR-1947448. Y.Y. is supported by the Research Grants Council Postdoctoral Fellowship, University Grants Committee, Hong Kong (PDFS2223-4S08) and the Faculty of Science at the Chinese University of Hong Kong.