SCEC Award Number 11166 View PDF
Proposal Category Collaborative Proposal (Integration and Theory)
Proposal Title Exploring the Probability of Fault-to-Fault Jumps During Earthquake Ruptures by Using Three-Dimensional Dynamic Simulations
Investigator(s)
Name Organization
Shuo Ma San Diego State University Ruth Harris United States Geological Survey
Other Participants 1 student
SCEC Priorities A9, A10, B2 SCEC Groups FARM, EFP, SHRA
Report Due Date 02/29/2012 Date Report Submitted N/A
Project Abstract
 In a depth-dependent stress environment rupture jumps more easily near the surface due to the low confining pressure. In 3D spontaneous rupture simulations we observe that ruptures on nearby faults can be triggered near the surface by P waves radiated from the main fault and these triggered rupture pulses propagate down dip and lead to successful rupture jumps. The likelihood of rupture jumps depend on many factors, such as the stress, strength conditions near the stepover, presence of fluids, inelastic deformation, many of which are largely unknown. It's premature at this stage to explore the probability of rupture jumps by numerical modeling.
Intellectual Merit P-wave triggering of rupture on nearby faults is possible. The triggering occurs more easily near the surface than at depth due to the low confining pressure.If the triggered rupture leads to successful rupture jumps they tend to propagate from surface to depth. This is consistent to some features of the kinematic rupture model of the Landers earthquake (Wald and Heaton, 1994).
Broader Impacts This project helped training of a PhD student (Evan Hirakawa) in earthquake modelling.
Exemplary Figure Figure 2. Snapshots of slip velocity mapped on the three fault segments every 1 s. The stepovers are 1 km wide. The material is assumed elastic. The dashed lines depict the fault overlap regions. The color scale is different for each panel. The peak slip rate is indicated at the lower right corner of each panel in m/s.