Community-Driven Code Comparisons for Three-Dimensional Dynamic Modeling of Sequences of Earthquakes and Aseismic Slip (SEAS)

Dynamic modeling of sequences of earthquakes and aseismic slip (SEAS) provides a self-consistent, physics-based framework to connect, interpret, and predict diverse geophysical observations across spatial and temporal scales. Amid growing applications of SEAS models, numerical code verification is essential to ensure reliable simulation results but is often infeasible due to the lack of analytical solutions. Here, we develop two benchmarks for three-dimensional (3D) SEAS problems to compare and verify numerical codes based on boundary-element, finite-element, and finite-difference methods, in a community initiative. Our benchmarks consider a planar vertical strike-slip fault obeying a rate- and state-dependent friction law, in a 3D homogeneous, linear elastic whole-space or half-space, where spontaneous earthquakes and slow slip arise due to tectonic-like loading. We use a suite of quasi-dynamic simulations from 10 modeling groups to assess the agreement during all phases of multiple seismic cycles. We find excellent quantitative agreement among simulated outputs for sufficiently large model domains and small grid spacings. However, discrepancies in rupture fronts of the initial event are influenced by the free surface and various computational factors. The recurrence intervals and nucleation phase of later earthquakes are particularly sensitive to numerical resolution and domain-size-dependent loading. Despite such variability, key properties of individual earthquakes, including rupture style, duration, total slip, peak slip rate, and stress drop, are comparable among even marginally resolved simulations. Our benchmark efforts offer a community-based example to improve numerical simulations and reveal sensitivities of model observables, which are important for advancing SEAS models to better understand earthquake system dynamics.

@article{id2769,
  author = {Jiang, Junle and Erickson, Brittany and Lambert, Valere and Abdelmeguid, Mohamed and Almquist, Martin  and Ampuero, Jean-Paul and Ando, Ryosuke   and Barbot, Sylvain and Cattania, Camilla   and Chen, Alexandre  and Dal Zilio, Luca and Duan,  Benchun  and Dunham, Eric  and Elbanna, Ahmed  and Gabriel, Alice-Agnes and Harvey,  Tobias and Huang, Yihe and Kaneko,  Yoshihiro  and Kozdon, Jeremy and Lapusta, Nadia and Li, Duo and Li,  Meng and Liang, Chao and Liu, Dunyu and Liu, Yajing  and Ozawa, So and Pranger, Casper and Segall, Paul and Sun, Yudong  and Thakur, Prithvi and Uphoff, Carsten  and van Dinther, Ylona   and Yang, Yuyun},
  doi = {10.1029/2021JB023519},
  journal = {Journal of Geophysical Research - Solid Earth},
  language = {en},
  pages = {e2021JB023519},
  title = {Community-Driven Code Comparisons for Three-Dimensional Dynamic Modeling of Sequences of Earthquakes and Aseismic Slip (SEAS)},
  url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2021JB023519},
  year = {2022},
}

%O Journal Article
%A Jiang, Junle
%A Erickson, Brittany
%A Lambert, Valere
%A Abdelmeguid, Mohamed
%A Almquist, Martin 
%A Ampuero, Jean-Paul
%A Ando, Ryosuke  
%A Barbot, Sylvain
%A Cattania, Camilla  
%A Chen, Alexandre 
%A Dal Zilio, Luca
%A Duan,  Benchun 
%A Dunham, Eric 
%A Elbanna, Ahmed 
%A Gabriel, Alice-Agnes
%A Harvey,  Tobias
%A Huang, Yihe
%A Kaneko,  Yoshihiro 
%A Kozdon, Jeremy
%A Lapusta, Nadia
%A Li, Duo
%A Li,  Meng
%A Liang, Chao
%A Liu, Dunyu
%A Liu, Yajing 
%A Ozawa, So
%A Pranger, Casper
%A Segall, Paul
%A Sun, Yudong 
%A Thakur, Prithvi
%A Uphoff, Carsten 
%A van Dinther, Ylona  
%A Yang, Yuyun
%R 10.1029/2021JB023519
%J Journal of Geophysical Research - Solid Earth
%G en
%P e2021JB023519
%T Community-Driven Code Comparisons for Three-Dimensional Dynamic Modeling of Sequences of Earthquakes and Aseismic Slip (SEAS)
%U https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2021JB023519
%D 2022