An instability theory for the formation of ribbed moraine, drumlins and mega-scale glacial lineations
We present a theory for the coupled flow of ice, subglacial water and subglacial sediment, which is designed to represent the processes which occur at the bed of an ice sheet. The ice is assumed to flow as a Newtonian viscous fluid, the water can flow between the till and the ice as a thin film, whi...
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ftpubmed:oai:pubmedcentral.nih.gov:4197478 2023-05-15T16:41:00+02:00 An instability theory for the formation of ribbed moraine, drumlins and mega-scale glacial lineations Fowler, A. C. Chapwanya, M. 2014-11-08 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4197478/ http://www.ncbi.nlm.nih.gov/pubmed/25383019 https://doi.org/10.1098/rspa.2014.0185 en eng The Royal Society Publishing http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4197478/ http://www.ncbi.nlm.nih.gov/pubmed/25383019 http://dx.doi.org/10.1098/rspa.2014.0185 © 2014 The Author(s) Published by the Royal Society. All rights reserved. Research Articles Text 2014 ftpubmed https://doi.org/10.1098/rspa.2014.0185 2015-11-15T01:10:50Z We present a theory for the coupled flow of ice, subglacial water and subglacial sediment, which is designed to represent the processes which occur at the bed of an ice sheet. The ice is assumed to flow as a Newtonian viscous fluid, the water can flow between the till and the ice as a thin film, which may thicken to form streams or cavities, and the till is assumed to be transported, either through shearing by the ice, squeezing by pressure gradients in the till, or by fluvial sediment transport processes in streams or cavities. In previous studies, it was shown that the dependence of ice sliding velocity on effective pressure provided a mechanism for the generation of bedforms resembling ribbed moraine, while the dependence of fluvial sediment transport on water film depth provides a mechanism for the generation of bedforms resembling mega-scale glacial lineations. Here, we combine these two processes in a single model, and show that, depending largely on the granulometry of the till, instability can occur in a range of types which range from ribbed moraine through three-dimensional drumlins to mega-scale glacial lineations. Text Ice Sheet PubMed Central (PMC) Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 470 2171 20140185 |
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Research Articles Fowler, A. C. Chapwanya, M. An instability theory for the formation of ribbed moraine, drumlins and mega-scale glacial lineations |
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Research Articles |
description |
We present a theory for the coupled flow of ice, subglacial water and subglacial sediment, which is designed to represent the processes which occur at the bed of an ice sheet. The ice is assumed to flow as a Newtonian viscous fluid, the water can flow between the till and the ice as a thin film, which may thicken to form streams or cavities, and the till is assumed to be transported, either through shearing by the ice, squeezing by pressure gradients in the till, or by fluvial sediment transport processes in streams or cavities. In previous studies, it was shown that the dependence of ice sliding velocity on effective pressure provided a mechanism for the generation of bedforms resembling ribbed moraine, while the dependence of fluvial sediment transport on water film depth provides a mechanism for the generation of bedforms resembling mega-scale glacial lineations. Here, we combine these two processes in a single model, and show that, depending largely on the granulometry of the till, instability can occur in a range of types which range from ribbed moraine through three-dimensional drumlins to mega-scale glacial lineations. |
format |
Text |
author |
Fowler, A. C. Chapwanya, M. |
author_facet |
Fowler, A. C. Chapwanya, M. |
author_sort |
Fowler, A. C. |
title |
An instability theory for the formation of ribbed moraine, drumlins and mega-scale glacial lineations |
title_short |
An instability theory for the formation of ribbed moraine, drumlins and mega-scale glacial lineations |
title_full |
An instability theory for the formation of ribbed moraine, drumlins and mega-scale glacial lineations |
title_fullStr |
An instability theory for the formation of ribbed moraine, drumlins and mega-scale glacial lineations |
title_full_unstemmed |
An instability theory for the formation of ribbed moraine, drumlins and mega-scale glacial lineations |
title_sort |
instability theory for the formation of ribbed moraine, drumlins and mega-scale glacial lineations |
publisher |
The Royal Society Publishing |
publishDate |
2014 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4197478/ http://www.ncbi.nlm.nih.gov/pubmed/25383019 https://doi.org/10.1098/rspa.2014.0185 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4197478/ http://www.ncbi.nlm.nih.gov/pubmed/25383019 http://dx.doi.org/10.1098/rspa.2014.0185 |
op_rights |
© 2014 The Author(s) Published by the Royal Society. All rights reserved. |
op_doi |
https://doi.org/10.1098/rspa.2014.0185 |
container_title |
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences |
container_volume |
470 |
container_issue |
2171 |
container_start_page |
20140185 |
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1766031442794512384 |