Stability and Uncertainty of Ice-Sheet Crystal Fabrics
Thesis (Ph.D.)--University of Washington, 2017-06 Ice crystal orientation fabric has a large effect on polycrystalline ice flow. In this thesis, I explore uncertainty of ice fabric measurements, and the related question of stability of ice crystal fabrics and anisotropic ice flow in ice sheets. I de...
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ftunivwashington:oai:digital.lib.washington.edu:1773/39750 2023-05-15T16:40:28+02:00 Stability and Uncertainty of Ice-Sheet Crystal Fabrics Hay, Michael John Waddington, Edwin D 2017-06 application/pdf http://hdl.handle.net/1773/39750 en_US eng Hay_washington_0250E_17421.pdf http://hdl.handle.net/1773/39750 CC BY anisotropy continuum mechanics glaciology ice physics machine learning statistics Geophysics Earth and space sciences Thesis 2017 ftunivwashington 2023-03-12T18:57:33Z Thesis (Ph.D.)--University of Washington, 2017-06 Ice crystal orientation fabric has a large effect on polycrystalline ice flow. In this thesis, I explore uncertainty of ice fabric measurements, and the related question of stability of ice crystal fabrics and anisotropic ice flow in ice sheets. I develop new estimates of uncertainty of fabric parameter estimates from thin-section data, and connect this to uncertainty in ice flow characteristics. To reduce this sampling error, I develop a new inverse method to infer fabric parameters from sonic velocity measurements and thin-section samples. I show a number of results concerning the stability of ice crystal fabrics in ice sheets. First, I show that small velocity gradient perturbations can induce large changes in ice fabric, which in turn affects anisotropic ice viscosity significantly. Next, I analyze the development of incipient fabric perturbations in coupled flow. I develop an analytical coupled model of anisotropic ice flow and fabric evolution, and show that the coupled system is unstable in many circumstances under ice-sheet flank flow and divide flow. Thesis Ice Sheet University of Washington, Seattle: ResearchWorks |
institution |
Open Polar |
collection |
University of Washington, Seattle: ResearchWorks |
op_collection_id |
ftunivwashington |
language |
English |
topic |
anisotropy continuum mechanics glaciology ice physics machine learning statistics Geophysics Earth and space sciences |
spellingShingle |
anisotropy continuum mechanics glaciology ice physics machine learning statistics Geophysics Earth and space sciences Hay, Michael John Stability and Uncertainty of Ice-Sheet Crystal Fabrics |
topic_facet |
anisotropy continuum mechanics glaciology ice physics machine learning statistics Geophysics Earth and space sciences |
description |
Thesis (Ph.D.)--University of Washington, 2017-06 Ice crystal orientation fabric has a large effect on polycrystalline ice flow. In this thesis, I explore uncertainty of ice fabric measurements, and the related question of stability of ice crystal fabrics and anisotropic ice flow in ice sheets. I develop new estimates of uncertainty of fabric parameter estimates from thin-section data, and connect this to uncertainty in ice flow characteristics. To reduce this sampling error, I develop a new inverse method to infer fabric parameters from sonic velocity measurements and thin-section samples. I show a number of results concerning the stability of ice crystal fabrics in ice sheets. First, I show that small velocity gradient perturbations can induce large changes in ice fabric, which in turn affects anisotropic ice viscosity significantly. Next, I analyze the development of incipient fabric perturbations in coupled flow. I develop an analytical coupled model of anisotropic ice flow and fabric evolution, and show that the coupled system is unstable in many circumstances under ice-sheet flank flow and divide flow. |
author2 |
Waddington, Edwin D |
format |
Thesis |
author |
Hay, Michael John |
author_facet |
Hay, Michael John |
author_sort |
Hay, Michael John |
title |
Stability and Uncertainty of Ice-Sheet Crystal Fabrics |
title_short |
Stability and Uncertainty of Ice-Sheet Crystal Fabrics |
title_full |
Stability and Uncertainty of Ice-Sheet Crystal Fabrics |
title_fullStr |
Stability and Uncertainty of Ice-Sheet Crystal Fabrics |
title_full_unstemmed |
Stability and Uncertainty of Ice-Sheet Crystal Fabrics |
title_sort |
stability and uncertainty of ice-sheet crystal fabrics |
publishDate |
2017 |
url |
http://hdl.handle.net/1773/39750 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
Hay_washington_0250E_17421.pdf http://hdl.handle.net/1773/39750 |
op_rights |
CC BY |
_version_ |
1766030872433131520 |