TY - JOUR
T1 - A Novel Hybrid Finite Element-Spectral Boundary Integral Scheme for Modeling Earthquake Cycles
T2 - Application to Rate and State Faults With Low-Velocity Zones
AU - Abdelmeguid, Mohamed
AU - Ma, Xiao
AU - Elbanna, Ahmed
N1 - Funding Information:
We thank Eric Dunham and Sylvain Barbot for their insightful reviews that helped improve the manuscript. We also thank Associate editor Ylona Van Dinther for her comments and input. This research has been supported by the National Science Foundation (CAREER Award 1753249) and the Southern California Earthquake Center through a collaborative agreement between NSF Grant EAR0529922 and USGS Grant 07HQAG0008. Additional funds for investigation of low‐velocity fault zones were provided by the Department of Energy under Award DE‐FE0031685. This work was prepared as an account of work sponsored by an agency of the U.S. Government. Neither the U.S. Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the U.S. Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the U.S. Government or any agency thereof. The data generated using the numerical algorithm corresponding to this study is available online ( https://doi.org/10.5281/zenodo.3379091 ).
PY - 2019/12/1
Y1 - 2019/12/1
N2 - We present a novel hybrid finite element-spectral boundary integral (SBI) scheme that enables efficient simulation of earthquake cycles. This combined finite element-SBI approach captures the benefits of finite elements in modeling problems with nonlinearities, as well as the computational superiority of SBI. The domain truncation enabled by this scheme allows us to utilize high-resolution finite elements discretization to capture inhomogeneities or complexities that may exist in a narrow region surrounding the fault. Combined with an adaptive time stepping algorithm, this framework opens new opportunities for modeling earthquake cycles with high-resolution fault zone physics. In this initial study, we consider a two-dimensional antiplane model with a vertical strike-slip fault governed by rate and state friction in the quasi-dynamic limit under the radiation damping approximation. The proposed approach is first verified using the benchmark problem BP-1 from the Southern California Earthquake Center sequence of earthquake and aseismic slip community verification effort. The computational framework is then utilized to model the earthquake sequence and aseismic slip of a fault embedded within a low-velocity fault zone (LVFZ) with different widths and compliance levels. Our results indicate that sufficiently compliant LVFZs contribute to the emergence of subsurface events that fail to penetrate to the free surface and may experience earthquake clusters with nonuniform interseismic time. Furthermore, the LVFZ leads to slip rate amplification relative to the homogeneous elastic case. We discuss the implications of our results for understanding earthquake complexity as an interplay of fault friction and bulk heterogeneities.
AB - We present a novel hybrid finite element-spectral boundary integral (SBI) scheme that enables efficient simulation of earthquake cycles. This combined finite element-SBI approach captures the benefits of finite elements in modeling problems with nonlinearities, as well as the computational superiority of SBI. The domain truncation enabled by this scheme allows us to utilize high-resolution finite elements discretization to capture inhomogeneities or complexities that may exist in a narrow region surrounding the fault. Combined with an adaptive time stepping algorithm, this framework opens new opportunities for modeling earthquake cycles with high-resolution fault zone physics. In this initial study, we consider a two-dimensional antiplane model with a vertical strike-slip fault governed by rate and state friction in the quasi-dynamic limit under the radiation damping approximation. The proposed approach is first verified using the benchmark problem BP-1 from the Southern California Earthquake Center sequence of earthquake and aseismic slip community verification effort. The computational framework is then utilized to model the earthquake sequence and aseismic slip of a fault embedded within a low-velocity fault zone (LVFZ) with different widths and compliance levels. Our results indicate that sufficiently compliant LVFZs contribute to the emergence of subsurface events that fail to penetrate to the free surface and may experience earthquake clusters with nonuniform interseismic time. Furthermore, the LVFZ leads to slip rate amplification relative to the homogeneous elastic case. We discuss the implications of our results for understanding earthquake complexity as an interplay of fault friction and bulk heterogeneities.
KW - earthquake cycles
KW - hybrid numerical scheme
KW - low-velocity fault zones
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U2 - 10.1029/2019JB018036
DO - 10.1029/2019JB018036
M3 - Article
AN - SCOPUS:85076191807
VL - 124
SP - 12854
EP - 12881
JO - Journal of Geophysical Research D: Atmospheres
JF - Journal of Geophysical Research D: Atmospheres
SN - 0148-0227
IS - 12
ER -