Advancing Simulations of Sequences of Earthquakes and Aseismic Slip [SEAS]

Junle Jiang, & Brittany A. Erickson

Submitted August 7, 2018, SCEC Contribution #8325, 2018 SCEC Annual Meeting Talk on Mon 14:00

Robust predictive models of earthquake source processes have fundamental importance in earthquake science. Numerical simulations of dynamic earthquake ruptures have excelled in reproducing detailed processes during individual events. To bridge the shorter and longer time scales, it is important to consider earthquake source processes that interact with slow tectonic deformation, through the simulation of Sequences of Earthquakes and Aseismic Slip (SEAS). In SEAS models, the interplay of aseismic periods and dynamic events gives rise to a wide range of geophysical observables such as aseismic deformation, microseismicity, and ground shaking during dynamic ruptures, providing an avenue to connect earthquake behavior to geological, paleoseismic, and geodetic observations from a fault zone. SEAS modeling can also determine which physics at what scales dominates the resulting fault behavior, aiding the interpretation of long-term seismicity patterns in large-scale models of fault systems that require various simplifications.

Understanding how earthquakes nucleate, propagate, and terminate necessitates the development of SEAS models capable of simulating pre-, inter- and postseismic slip and loading between earthquakes. Multiscale faulting processes and multiple physical factors involved lead to the complexity of SEAS models, posing significant challenges for numerical simulations. This reality requires collaborations of researchers to compare and verify simulation results. Over the past year we have initiated a community code-verification effort, with the goals to further advance our computational capabilities, promote robust and reproducible earthquake science, and develop best practices and tools for the broader community. During the first SEAS workshop this spring, we brought together ~20 modelers to participate in our first benchmark problem, a 2D quasi-dynamic crustal faulting problem that serves as the first step to ensuring that different methodologies can produce closely matching results. The initial success of this benchmark prepares us to consider models with further complexities, including irregular earthquake patterns, nonvertical faults, 3D problems, and additional physics such as inelasticity and full dynamic effects, as we move forward. This community exercise will foster the development of a new generation of accurate SEAS models, towards a long-term goal to validate and integrate these models with geophysical observations.

Key Words
fault mechanics, earthquake physics, computational methods, community benchmarks

Jiang, J., & Erickson, B. A. (2018, 08). Advancing Simulations of Sequences of Earthquakes and Aseismic Slip [SEAS]. Oral Presentation at 2018 SCEC Annual Meeting.

Related Projects & Working Groups
Fault and Rupture Mechanics (FARM)