Plate Boundary Geomechanical Model of Northern California Bay Area
Description:
This project aims to improve understanding of fault slip rates at the complex and hazardous tectonic plate boundary in the Bay Area of northern California. Fault slip rates are the average movement along a fault per year. In order to better understand observed fault slip rate data and generate representative fault slip rates to improve seismic hazard mitigation, we are building a mechanical model that produces fault slip rates across this complex, plate-bounding fault system. This quasistatic model accounts for the constitutive behavior of the rocks surrounding the faults, as well as the conservation of mass and momentum. The complex, segmented, non-planar, 3D faults are free to slip together in response to applied plate motions. In this way, the model accounts for the communication of segmented faults with one another through stress transfer, as slip is partitioned across the complex system.
To generate this model, we used fault traces from the Geologic Deformation Model used in the 2023 National Seismic Hazard Model. Selecting the fault traces within a 200 km by 200 km region across the Bay Area, we translate our filtered fault traces to the Universal Transverse Coordinator system and use a Python script to convert the traces into a readable format for our meshing program. Subsequently, we verified our structural model by visually comparing our new faults to the original model. To run the mechanical models we will use Tandem, an elastostatic solver that utilizes a discontinuous Galerkin method and is optimized for High Performance Computing platforms. We will then compare our simulated slip rates with those gathered in the field that are included in the Geologic Deformation Model. Adjustments will be made to fault connectivity in order to achieve the most accurate seismic deformation model. With these efforts, we aim to better understand the 3D fault geometry of this region and improve seismic hazard mitigation in the Bay Area.
Session: Exploring the Complexity of Fault Discontinuities [Poster]
Type: Poster
Date: 4/17/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Nathan
Student Presenter: Yes
Invited Presentation:
Poster Number: 81
Authors
Nathan Johnson Presenting Author Corresponding Author nathan0johnson2021@gmail.com San Jose State University |
Anh Tran anh.t.tran06@sjsu.edu San Jose State University |
Simon Truong simon.truong@sjsu.edu San Jose State University |
Elizabeth Madden Elizabeth.madden@sjsu.edu San Jose State University |
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Plate Boundary Geomechanical Model of Northern California Bay Area
Session
Exploring the Complexity of Fault Discontinuities