Electronic Theses and Dissertations

Date

2025

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Earth Sciences

Committee Chair

Christodoulos Kyriakopoulos

Committee Member

Eunseo Choi

Committee Member

Robert Smalley

Committee Member

Shahram Pezeshk

Committee Member

Thomas Goebel

Abstract

Earthquakes generate stress perturbations capable of influencing adjacent faults and magmatic systems across a range of spatial and temporal scales. This work investigates how dynamic and static earthquake-induced stress changes affect geological structures in two different tectonic settings: major continental fault systems and subduction zones. The first part of this study examines dynamic rupture interactions between the southern San Andreas Fault and an adjacent normal fault beneath the Salton Sea. Our results indicate that dynamic rupture simulations informed by high-resolution seismic reflection profiles of the normal fault help us uncover the direction of rupture propagation of past events on the southern San Andreas Fault. Specifically, north-to-south ruptures are more efficient in triggering slip on the normal fault, whereas south-to-north ruptures are less likely. Furthermore, they highlight the crucial role of a variable locking depth on fault-to-fault dynamic interactions. The second part of this work investigates static stress changes induced by megathrust earthquakes and their impact on vertical and horizontal magmatic pathways. By incorporating a broad range of rigidity values, our models capture end-member stress behaviors that are not represented under the commonly assumed homogeneous conditions. Results show that material heterogeneity significantly affects stress transfer, with rigid upper mantle rocks amplifying stress changes and more compliant crustal materials dampening them. Our models provide a comprehensive framework for evaluating normal stress changes along magmatic systems, and the spatial extent of stress transfer, and the impact of geological heterogeneities. Results from this dissertation enhance our understanding of crustal responses to large earthquakes and provide new insights into seismic hazard assessments along continental multi-fault systems and volcanic activity near subduction environments worldwide.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to ProQuest.

Notes

Open Access

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