The Ingredients Needed for Realistic Dynamic Earthquake Rupture Simulations

Ruth A. Harris

Submitted September 11, 2022, SCEC Contribution #11884, 2022 SCEC Annual Meeting Poster #124

Many mysteries about earthquake mechanics remain unsolved, including significant questions about what causes large earthquakes to stop after they have started propagating and which physical processes of the earthquake source are most likely to affect strong ground shaking. The SCEC-USGS dynamic earthquake rupture group aims to solve these mysteries, using computational simulations of spontaneous earthquake rupture propagation in conjunction with available field and laboratory data. Our group met four times in workshops over the past three years to discuss ‘ingredients’ (assumptions) needed for developing comprehensive computational simulations: fault geometry, fault friction, rock properties, and stress conditions. We need to figure out what choices to make for each of these ingredients, among the myriad of possibilities, and which of the ingredients can be simplified, due to either lack of knowledge of their true nature or lack of sufficient computational power to include all of the fine details. At our ingredient-focused workshops, we learned about SCEC community models useful for our endeavors as well as new research often applied to specific earthquake settings. We also debated the relative significance of each ingredient. Key lessons we have learned during our discussions are that all four of the ingredients (fault geometry, fault friction, rock properties, and stress conditions) are important, and that sometimes these should be implemented in not just two-dimensions, but in the full three-dimensional space that is Earth’s seismogenic zone. The overall lesson is that earthquake mechanics is still a nascent topic, and new field observations, lab experiments, and computational simulations are needed to help provide more solutions to how earthquakes work.

Key Words
dynamic rupture, earthquake source mechanics, computational modeling, fault geometry, rock properties, fault friction, stress conditions

Citation
Harris, R. A. (2022, 09). The Ingredients Needed for Realistic Dynamic Earthquake Rupture Simulations. Poster Presentation at 2022 SCEC Annual Meeting.

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