Influence of fault roughness on surface displacement: From numerical simulations to coseismic slip distributions
Résumé
Field studies have characterized natural faults as rough, nonplanar surfaces at all scales. Fault roughness induces local stress perturbations during slip, which dramatically affect rupture behavior, resulting in slip heterogeneity. However, the relation between fault roughness and slip heterogeneity remains a key knowledge gap between current numerical and field studies. In this study, we analyze numerical simulations of earthquake rupture to determine how roughness influences final slip. Using a rupture catalog containing thousands of dynamic rupture simulations on band-limited self-similar fractal fault profiles with varying roughness and background shear stress levels, we quantify how fault roughness affects the spectral characteristics of the resulting slip distribution. We find that slip distributions become increasingly more self-affine, that is, containing more short wavelength fluctuations as compared to the self-similar fault profiles, as roughness increases. We also find that, at very short wavelengths (<1km), the fractal dimension of the slip distributions dramatically changes with increasing roughness, background shear stress,
Domaines
Tectonique
Origine : Fichiers produits par l'(les) auteur(s)