Fault geometric complexities exhibit fractal characteristics over a wide range of spatial scales (km) and strongly affect the rupture process at corresponding scales. Numerical rupture simulations provide a framework to quantitatively investigate the relationship between a fault's roughness and its seismic characteristics. Fault discretization however introduces an artificial lower limit to roughness. Individual fault patches are planar and sub-patch roughness –roughness at spatial scales below fault-patch size– is not incorporated. Does negligence of sub-patch roughness measurably affect the outcome of earthquake rupture simulations? We approach this question with a numerical parameter space investigation and demonstrate that sub-patch roughness significantly modifies the slip-strain relationship –a fundamental aspect of dislocation theory. Faults with sub-patch roughness induce less strain than their planar-fault equivalents at distances beyond the length of a slipping fault. We further provide regression functions that characterize the stochastic effect sub-patch roughness.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). No financial or other types of conflicts of interest exist for the authors regarding this manuscript. Figures in the main manuscript and supporting online material provide all data used in this investigation. We want to thank M. Galis for many stimulating discussion. We also want to thank the reviewers for their constructive criticism and helpful comments that improved this study.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)