Resolving Simulated Sequences of Earthquakes and Fault Interactions: Implications for Physics-Based Seismic Hazard Assessment
- Creators
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Lambert, Valère
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Lapusta, Nadia
Abstract
Physics-based numerical modeling of earthquake source processes strives to predict quantities of interest for seismic hazard, such as the probability of an earthquake rupture jumping between fault segments. How to assess the predictive power of numerical models remains a topic of ongoing debate. Here, we investigate how sensitive the outcomes of numerical simulations of sequences of earthquakes and aseismic slip are to choices in numerical discretization and treatment of inertial effects, using a simplified 2-D crustal fault model with two co-planar segments separated by a creeping barrier. Our simulations demonstrate that simplifying inertial effects and using oversized cells significantly affects the resulting earthquake sequences, including the rate of two-segment ruptures. We find that fault models with different properties and modeling assumptions can produce similar frequency-magnitude statistics and static stress drops but have different rates of two-segment ruptures. For sufficiently long faults, we find that long-term sequences of events can substantially differ even among simulations that are well resolved by standard considerations. In such simulations, some outcomes, such as static stress drops, are similar among adequately resolved simulations, whereas others, such as the rate of two-segment ruptures, can be highly sensitive to numerical procedures and modeling assumptions. While it is possible that the response of models with additional ingredients -Realistic fault geometry, fluid effects, etc. -Would be less sensitive to numerical procedures, our results emphasize the need to examine the potential dependence of simulation outcomes on the modeling procedures and resolution, particularly when assessing their predictive value for seismic hazard assessment.
Additional Information
© 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Issue Online: 25 October 2021; Version of Record online: 25 October 2021; Accepted manuscript online: 14 October 2021; Manuscript accepted: 10 October 2021; Manuscript revised: 15 September 2021; Manuscript received: 07 April 2021. This study was supported by the National Science Foundation (grants EAR 1142183 and 1520907) and the Southern California Earthquake Center (SCEC), contribution No. 10089. SCEC is funded by NSF Cooperative Agreement EAR-1033462 and USGS Cooperative Agreement G12AC20038. Numerical simulations for this study were carried out on the High Performance Computing Center cluster of the California Institute of Technology. This study was motivated by insightful discussions within the SCEC community. Data Availability Statement: Details about the fault models and numerical parameters for calculations are provided in the main and supplementary text, and Tables 1–2. Data were not used, nor created for this research.Attached Files
Published - 2021JB022193.pdf
Submitted - essoar.10506727.1.pdf
Supplemental Material - 2021jb022193-sup-0001-supporting_information_si-s01.pdf
Files
Additional details
- Eprint ID
- 108779
- Resolver ID
- CaltechAUTHORS:20210421-092618302
- NSF
- EAR-1142183
- NSF
- EAR-1520907
- Southern California Earthquake Center (SCEC)
- NSF
- EAR-1033462
- USGS
- G12AC20038
- Created
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2021-04-21Created from EPrint's datestamp field
- Updated
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2022-11-15Created from EPrint's last_modified field
- Caltech groups
- Center for Geomechanics and Mitigation of Geohazards (GMG), Division of Geological and Planetary Sciences, Seismological Laboratory
- Other Numbering System Name
- Southern California Earthquake Center
- Other Numbering System Identifier
- 10089