SCEC Award Number 20113 View PDF
Proposal Category Collaborative Proposal (Integration and Theory)
Proposal Title Advancing Simulations of Sequences of Earthquakes and Aseismic Slip (SEAS)
Investigator(s)
Name Organization
Brittany Erickson University of Oregon Junle Jiang Cornell University Michael Barall Invisible Software, Inc. Rowena Lohman Cornell University
Other Participants Approximately 20 individuals.
SCEC Priorities 1d, 1e, 3f SCEC Groups FARM, SDOT, CS
Report Due Date 03/15/2021 Date Report Submitted 03/15/2021
Project Abstract
 Developing robust predictive models of earthquake source processes is one of the main SCEC goals. We are contributing to this goal through the development of computational methods for simulating Sequences of Earthquakes and Aseismic Slip (SEAS). With SCEC support this past year, we have:
- Engaged a growing number of researchers who are committed to recent benchmark exercises, or are
interested in our current activity and potential future participation (~36 PIs, ~34 students/postdocs).
- Designed two new benchmarks, BP3 (dipping fault 2D case) and BP5 (a second 3D case).
- Organized our fourth SEAS-themed workshop in October 2020 for sharing advancements in the field
and discussing results of benchmarks BP3-QD and BP5-QD (the quasi-dynamic versions of BP3 and
BP5). A total of 54 people participated.
- In the BP3-QD exercises, we found excellent agreements between 3 modeling groups (with 3
additional groups performing the exercise after the workshop), when similar domain sizes and
boundary conditions were adopted.
- In the BP5-QD exercises, we explored long-term time series at various fault locations, showing good
agreements across modeling groups. Comparisons of the rupture contours showed minor
discrepancies attributable to different treatments of the surface nodes and/or domain sizes.
- Presented our results at the 2020 SCEC Annual Meeting.
- Have two new papers (one on our recent 2D benchmark problems, and one on 3D) in preparation,
with aimed submission in late Spring 2021.
- Welcomed new co-leader Valère Lambert, who will be taking over Junle Jiang’s position .
Intellectual Merit This funding has supported the development of computational codes for SEAS models in order to advance robust predictive models of earthquake source processes, which is one of the main SCEC goals. One of the significant challenges in SEAS modeling efforts arises from the varying temporal and spatial scales that characterize earthquake source behavior. Computations are further complicated when material heterogeneities, bulk inelastic responses, fault nonplanarity, and their evolution with time and slip, are included. However, accounting for such complexity is widely recognized as crucial for understanding the real Earth and predicting seismic hazards.
Broader Impacts This project has supported a SCEC working group (our last workshop in October 2020 had 54 participants), with 34 students/postdocs are involved. Many of the SEAS codes are published as open-source repositories to be used by other scientists.
Exemplary Figure Figure 1: Left: BP3-QD considers a planar, dipping fault embedded in a homogeneous, linear
elastic half-space with a free surface where motion is plane-strain. The fault is governed by
rate-and-state friction down dip to a distance Wf and creeps at an imposed constant rate Vp down
to the infinite dip distance. The left and right sides of the fault are labeled with “(-)” and “(+)”,
respectively. For the detailed benchmark description, please see
https://strike.scec.org/cvws/seas/index.html . Right: time series from two different codes
(boundary element and finite difference) showing discrepancies attributable to thrust versus
normal faulting assumption.