Date of Award:
8-2026
Document Type:
Thesis
Degree Name:
Master of Science (MS)
Department:
Geosciences
Committee Chair(s)
Srisharan Shreedharan
Committee
Srisharan Shreedharan
Committee
David C. Bolton
Committee
Anthony R. Lowry
Abstract
Tectonic faults are made of many kinds of rocks and minerals, creating natural weak and strong zones along faults where earthquakes occur. These differences can affect how faults move, including whether slip occurs slowly and quietly or suddenly and destructively during an earthquake. However, it is not fully understood how these variations influence when earthquakes start, how fast they spread, and whether they stop or grow into large ruptures. This research studies how different fault materials interact during earthquake slip. Using a large laboratory machine that simulates fault movement under realistic conditions, we recreate earthquake processes and closely measure how faults begin to slip, how ruptures travel, and how they stop. The experiments focus on mixtures of quartz, a strong mineral commonly found in Earth’s crust, and smectite clay, a weaker material often associated with slow fault movement.
Results from this work show that dry, clay-rich regions can relieve local shear-stress accumulation and focus overall stress and strain in nearby, stronger regions of a fault, helping to trigger sudden earthquake rupture. This finding suggests that slow-slipping portions of faults may play a more active role in earthquake initiation than previously recognized. Future work will examine how these materials deform at the microscopic scale to better understand how stress builds up before earthquakes occur. This research improves our understanding of the physical processes that control earthquakes and may help scientists better assess earthquake hazard in regions prone to destructive earthquakes and tsunamis.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Recommended Citation
Aguilar, Alejandro, "The Role of Heterogeneity in Earthquake Rupture Dynamics: Insights From Friction Experiments on a 1-Meter Laboratory Fault" (2026). All Graduate Theses and Dissertations, Fall 2023 to Present. 895.
https://digitalcommons.usu.edu/etd2023/895
Included in
Copyright for this work is retained by the student. If you have any questions regarding the inclusion of this work in the Digital Commons, please email us at .