SCEC Award Number 22029 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Predicting Ground Motions from Complex Fault Models
Investigator(s)
Name Organization
Victor Tsai Brown University
Other Participants
SCEC Priorities 4a, 2d, 3a SCEC Groups Seismology, FARM, GM
Report Due Date 03/15/2023 Date Report Submitted 08/05/2023
Project Abstract
 Understanding the cause of damaging high-frequency earthquake ground motions is important from both a fundamental physics perspective and to better prepare for earthquake hazards. However, there are a number of competing physical models for how these ground motions are produced within complex fault zones, with slip heterogeneity, structural impacts and damage creation being amongst those most debated. While ground motion predictions for these three models exist, it is challenging to directly compare the predictions and thus to have testable differences to compare with observations. We have evaluated the impact model’s predictions in the most extreme situations of the simplest and most complex fault systems and found that the model predicts that faults with less geometrical complexity should have less seismicity, particularly events of sizes related to the geometric scale. In particular, perfectly planar faults are predicted to only creep and not exhibit seismogenic behavior.
Intellectual Merit This work helps understand the fundamental causes of earthquake ground motions as well as why earthquakes themselves occur. It points out that there may be very important geometrical considerations that are as important to understanding earthquakes as (rate-and-state dependent) friction, and thus challenges the existing paradigm for understanding earthquakes. The work builds on an original idea that was introduced by the PI just a few years ago.
Broader Impacts If earthquake ground motions and the cause of earthquakes can be better understood, society may benefit significantly by being able to better respond and evaluate where more damaging earthquakes will occur.
Exemplary Figure No figures created for this theoretical work.