Research Summaries

Back Collaborative Research: From Loading to Dynamic Rupture - How do Fault Geometry and Material Heterogeneity Affect the Earthquake Cycle?

Fiscal Year 2016
Division Graduate School of Engineering & Applied Science
Department Applied Mathematics
Investigator(s) Kozdon, Jeremy E.
Sponsor National Science Foundation (NSF)
Summary Seismic hazard analysis requires an understanding of the earthquake cycle including the interaction of remote loading and near-fault structure. Currently, no existing models can account for both the interseismic and coseismic periods with complex fault geometries, heterogeneous materials, and plastic deformation. To address this, a numerical model that rigorously accounts for the interseismic loading as well as rupture dynamics in both two- and three-dimensions is proposed. In order to capture the effect of slow tectonic loading on the evolution of the stress field, a computationally efficient quasi-static model is developed. When inertial effects become important, the model switches to a fully dynamic description where the wavefield is modeled along with its interaction with frictional fault interfaces. All stages of the earthquake cycle are modeled in a single, self-consistent computational and mathematical framework capable of capturing both complex geometries and material descriptions.
The specific tasks of the project group are:
1. Develop a parallel quasi-static and dynamic rupture modeling environment in two- and three-dimensions using a spatially adaptive discontinuous Galerkin formulation. The unified model includes capabilities for handling complex geometries (including branches, bends, and step overs), general boundary conditions, plastic deformation, and variable material and frictional properties.
2. Understand the sensitivity of modeling results on the switching criterion between the quasi-static and fully dynamic regimes.
3. Explore the impact of the inclusion of plasticity on the earthquake cycle when dynamics are rigorously accounted for.
4. Assess the role that residual stress plays in dictating the preferred rupture direction in bimaterial problems over the course of many earthquake cycles and compare with observations such as those from Parkfield.
5. Develop models which include large-scale fault nonplanarity (fault bends and branches) to understand how geometry affects nucleation location, recurrence interval, magnitude, and evolution of the near-fault stress field.
Keywords Earthquake Numerical Methods PDEs Wave Propagation
Publications Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal
Data Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal