Process-based modeling of ice stream shear margins and their effect on ice stream stability

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Abstract/Contents

Abstract
The largest uncertainty in projections of sea-level rise is ascribed to mass loss associated with fast ice flow on Earth's ice sheets. This uncertainty is a result of an incomplete understanding of the subglacial environment, and the physics governing this interface. Regions of fast ice flow without topographic bounds, called ice streams, are particularly sensitive to the underlying subglacial properties. Here, we explore the underlying physics governing ice stream stability in several regions across the West Antarctic ice sheet. Specifically, we develop models that interrogate the role of subglacial conditions on the lateral bounds of ice streams, known as shear margins. Shear margins are liable to migrate, and their location is often controlled by dynamic processes. First, we demonstrate that rapidly evolving subglacial processes, such as meltwater drainage, have the potential to induce changes in large-scale ice dynamics on decadal timescales. Next, we develop a model to investigate the relative role of sediment and hardrock on ice stream stability. We then develop a technique to generate synthetic radargrams in regions of complex ice deformation. Finally, we develop a method that includes both dynamic shear margins, and grounding lines to enable research into potential coupling of these two sensitive boundaries. In each of these cases, we connect the model to targeted areas of interest across Antarctica, and connect the underlying physics to observations at the surface. Through these investigations, this thesis develops a more detailed understanding of the role of the subglacial environment on ice stream stability.

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 Elsworth, Cooper Wheeler
Degree supervisor Suckale, Jenny
Thesis advisor Suckale, Jenny
Thesis advisor Dunham, Eric
Thesis advisor Schroeder, Dustin
Degree committee member Dunham, Eric
Degree committee member Schroeder, Dustin
Associated with Stanford University, Department of Geophysics.

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Cooper Wheeler Elsworth.
Note Submitted to the Department of Geophysics.
Thesis Thesis Ph.D. Stanford University 2019.
Location electronic resource

Access conditions

Copyright
© 2019 by Cooper Wheeler Elsworth
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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