SCEC Award Number 20166 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Hero-run San Andreas Scenario Simulation with Iwan-type Nonlinearity
Investigator(s)
Name Organization
Daniel Roten San Diego State University Kim Olsen San Diego State University Steven Day San Diego State University Yifeng Cui University of California, San Diego
Other Participants
SCEC Priorities 4a, 4b, 4d SCEC Groups CS, GM, Seismology
Report Due Date 03/15/2021 Date Report Submitted 05/15/2024
Project Abstract
 SCEC project 20166 aimed to finalize the implementation of multi-surface (Iwan-type) nonlinearity in the GPU version of the discontinuous grid AWP finite difference wave propagation code. The project also aimed to carry out a hero-run simulation for a large M 7.5-7.8 earthquake on the southern San Andreas fault. Most of the required functions for the calculation of multi-surface nonlinearity had been implemented in AWP in the framework of previous SCEC-funded projects, but the code had not been tested fully before the start of project 20166. In particular, previous verification benchmarks simulated wave propagation in laterally homogeneous media for simple sources and short duration. During this project, multiple bugs in the implementation of Iwan-nonlinearity were found which had to be addressed before production simulations. These bug fixes and new tests claimed all of the time allocated to the project, leaving no time for the proposed 5 Hz hero run. However, the implementation of Iwan nonlinearity and optimization was completed successfully. AWP-Iwan has subsequently been used to carry out high-frequency, multi-surface simulations in the framework of other projects.
Intellectual Merit The proposed work will improve our understanding about the impact of nonlinear effects at low and intermediate frequencies during large earthquakes.
Broader Impacts Predicting ground motions at frequencies up to 5 Hz, including realistic nonlinearity, will have be of significance to the fields of seismology, earthquake engineering and computational science. The deployed code will be made available to the community for future research. We anticipate to create visualizations of the wave propagation, including development of nonlinear deformation, which will be of interest to broad audience (including the general public).
Exemplary Figure Figure 4