The physics of friction and fracture : applications to dike propagation, earthquake triggering, and slow slip mechanics
Abstract/Contents
- Abstract
- Friction and fracture processes are ubiquitous in the brittle crust. Thus understanding the physics of these processes is of paramount importance to successfully model and interpret a wide variety of geological phenomena such as seismic and volcanic activity. In this dissertation, I develop theory and models based on the current understanding of the physics of friction and fracture. These physics-based models are then applied to a broad class of problems related to dike propagation, induced and triggered seismicity, and slow slip mechanics. In order to couple together the underlying physics of friction and fracture to data and observable characteristic of transient behavior in the crust we need models and constitutive relationships. This dissertation is mainly on making this connection, the challenges involved, and comparison with observations. The first challenge addressed in this dissertation is to connect fault friction and microseismicity (Chapter 2). I use the experimentally derived theory of rate-and-state friction to compute the time to instability for a spring slider under arbitrary stressing history. This analytical result is used to describe a population of spring-sliders, which represents a population of seismic sources with varying initial conditions. This theory results in a constitutive relationship that relates to seismicity production and stressing history. The theory is extended well beyond what has been previously explored, in particular, where I account for interactions between seismic sources (Chapter 3). This new interaction theory is applied to several practical problems such as fault slip models and earthquake migration through cascading. Further applications of the theory from Chapter 2 are explored in Chapter 4. Where a physics-based model of a dike intrusion is developed and deformation and seismicity are modeled in a fully consistent manner. The results suggest that dike induced earthquakes are triggered on preexisting faults. Furthermore, the results give insight into the frictional structure of the crust, which needs to be heterogeneous to satisfy the temporal and spatial distribution of the seismicity. The last two Chapters (5 and 6) explore in more details the mechanics of faults and dike intrusions respectively and are mostly independent of other chapters. In chapter 5, I account for poroelastic coupling the nucleation of frictional instabilities. This work leads to a new novel theory of slow slip, which demonstrates that slow slip nucleates spontaneously on mildly rate-strengthening faults under certain circumstances when slip couples to normal stress perturbation. In the final chapter, I show how the growth of dikes and depressurization of magma chambers are coupled through fully coupled simulations. The simulations provide new insight into how a dike lengthens with time before finally arresting.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2019; ©2019 |
| Publication date | 2019; 2019 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Heimisson, Elias Rafn |
|---|---|
| Degree supervisor | Segall, Paul, 1954- |
| Thesis advisor | Segall, Paul, 1954- |
| Thesis advisor | Dunham, Eric |
| Thesis advisor | Ellsworth, William L |
| Degree committee member | Dunham, Eric |
| Degree committee member | Ellsworth, William L |
| Associated with | Stanford University, Department of Geophysics. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Elias Rafn Heimisson. |
|---|---|
| Note | Submitted to the Department of Geophysics. |
| Thesis | Thesis Ph.D. Stanford University 2019. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2019 by Elias Rafn Heimisson
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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