SCEC Award Number 25274 View PDF
Proposal Category Individual Research Project (Single Investigator / Institution)
Proposal Title Simulating the evolution of fault zone structure in 2D fully dynamic earthquake cycle simulations with continuum brittle damage
Investigator(s)
Name Organization
Yihe Huang University of Michigan
SCEC Milestones C2-1, C3-1 SCEC Groups FARM, SDOT, Geology
Report Due Date 03/15/2026 Date Report Submitted 03/14/2026
Project Abstract
 Fault zones co-evolve with seismic and aseismic slip continuously over earthquake cycles, during which spontaneously generated off-fault damage plays an important role in the overall energy budget. However, the contribution of earthquakes and interseismic deformation to the evolution and distribution of off-fault damage has not been well quantified in fully dynamic earthquake cycle simulations. We propose to model earthquake rupture and interseismic slip in 2D fully dynamic earthquake cycle simulations with continuum brittle damage. The simulations will enable the spontaneous generation of off-fault damage during earthquakes and interseismic periods, which will be used to better understand the spatial and temporal variations of fault zone structures. We will also explore the interplay between fault zone strengths and spontaneous generation of off-fault damage at various spatial scales through seismic cycles and investigate how it influences seismicity distribution and energy budget. The proposal directly addresses the SCEC science milestone C2-1 and C3-1 by modeling the spontaneous generation of off-fault damage during earthquake cycles and quantifying the contribution of coupled evolution of earthquakes and fault zones to the seismic and aseismic slip histories on active faults.
Intellectual Merit This project directly addresses two basic questions in the SCEC 2025 Science Plan: (1) Improve the understanding of damage rheology governing degradation of elastic moduli during brittle failure and healing in interseismic periods and (2) Assess space- and time-dependent geophysical variables that influence seismicity, including foreshock and aftershock rates as well as swarms across the SAFS. We develop new tools to simulate the co-evolution of fault stress and spontaneous fault damage generation during earthquake cycles and decipher the role of fault zone evolution in the generation of earthquake sequences and the overall energy budget.
Broader Impacts The project supports the training of a graduate student who has successfully implemented the framework of continuum damage rheology in fully dynamic earthquake cycle simulations. The participation in this project allows the student to present in various conferences and workshops. He is also the lead author in a peer-reviewed paper about our methodology and initial results. The project can provide crucial insights into the mechanisms of small and large earthquakes and the development of fault zone structures during coseismic and interseismic periods, which will help fill the knowledge gaps that prevent physics-informed seismic hazard analysis.
Project Participants Both the PI and graduate student have worked on the project.
Exemplary Figure Figure 2 (by Peng Zhai): Spatial distribution of (a) damage variable and (b) equivalent cumulative plastic strain after the 10th event.
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