Spatial heterogeneity in subglacial drainage driven by till erosion
The distribution and drainage of meltwater at the base of glaciers sensitively affects fast ice flow. Previous studies suggest that thin meltwater films between the overlying ice and a hard-rock bed channelize into efficient drainage elements by melting the overlying ice. However, these studies do n...
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crroyalsociety:10.1098/rspa.2019.0259 2024-06-02T07:55:55+00:00 Spatial heterogeneity in subglacial drainage driven by till erosion Kasmalkar, Indraneel Mantelli, Elisa Suckale, Jenny National Science Foundation 2019 http://dx.doi.org/10.1098/rspa.2019.0259 https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.2019.0259 https://royalsocietypublishing.org/doi/full-xml/10.1098/rspa.2019.0259 en eng The Royal Society https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences volume 475, issue 2228, page 20190259 ISSN 1364-5021 1471-2946 journal-article 2019 crroyalsociety https://doi.org/10.1098/rspa.2019.0259 2024-05-07T14:16:28Z The distribution and drainage of meltwater at the base of glaciers sensitively affects fast ice flow. Previous studies suggest that thin meltwater films between the overlying ice and a hard-rock bed channelize into efficient drainage elements by melting the overlying ice. However, these studies do not account for the presence of soft deformable sediment observed underneath many West Antarctic ice streams, and the inextricable coupling that sediment exhibits with meltwater drainage. Our work presents an alternate mechanism for initiating drainage elements such as canals where meltwater films grow by eroding the sediment beneath. We conduct a linearized stability analysis on a meltwater film flowing over an erodible bed. We solve the Orr–Sommerfeld equation for the film flow, and we compute bed evolution with the Exner equation. We identify a regime where the coupled dynamics of hydrology and sediment transport drives a morphological instability that generates spatial heterogeneity at the bed. We show that this film instability operates at much faster time scales than the classical thermal instability proposed by Walder. We discuss the physics of the instability using the framework of ripple formation on erodible beds. Article in Journal/Newspaper Antarc* Antarctic The Royal Society Antarctic Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 475 2228 20190259 |
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Open Polar |
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The Royal Society |
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crroyalsociety |
language |
English |
description |
The distribution and drainage of meltwater at the base of glaciers sensitively affects fast ice flow. Previous studies suggest that thin meltwater films between the overlying ice and a hard-rock bed channelize into efficient drainage elements by melting the overlying ice. However, these studies do not account for the presence of soft deformable sediment observed underneath many West Antarctic ice streams, and the inextricable coupling that sediment exhibits with meltwater drainage. Our work presents an alternate mechanism for initiating drainage elements such as canals where meltwater films grow by eroding the sediment beneath. We conduct a linearized stability analysis on a meltwater film flowing over an erodible bed. We solve the Orr–Sommerfeld equation for the film flow, and we compute bed evolution with the Exner equation. We identify a regime where the coupled dynamics of hydrology and sediment transport drives a morphological instability that generates spatial heterogeneity at the bed. We show that this film instability operates at much faster time scales than the classical thermal instability proposed by Walder. We discuss the physics of the instability using the framework of ripple formation on erodible beds. |
author2 |
National Science Foundation |
format |
Article in Journal/Newspaper |
author |
Kasmalkar, Indraneel Mantelli, Elisa Suckale, Jenny |
spellingShingle |
Kasmalkar, Indraneel Mantelli, Elisa Suckale, Jenny Spatial heterogeneity in subglacial drainage driven by till erosion |
author_facet |
Kasmalkar, Indraneel Mantelli, Elisa Suckale, Jenny |
author_sort |
Kasmalkar, Indraneel |
title |
Spatial heterogeneity in subglacial drainage driven by till erosion |
title_short |
Spatial heterogeneity in subglacial drainage driven by till erosion |
title_full |
Spatial heterogeneity in subglacial drainage driven by till erosion |
title_fullStr |
Spatial heterogeneity in subglacial drainage driven by till erosion |
title_full_unstemmed |
Spatial heterogeneity in subglacial drainage driven by till erosion |
title_sort |
spatial heterogeneity in subglacial drainage driven by till erosion |
publisher |
The Royal Society |
publishDate |
2019 |
url |
http://dx.doi.org/10.1098/rspa.2019.0259 https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.2019.0259 https://royalsocietypublishing.org/doi/full-xml/10.1098/rspa.2019.0259 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences volume 475, issue 2228, page 20190259 ISSN 1364-5021 1471-2946 |
op_rights |
https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ |
op_doi |
https://doi.org/10.1098/rspa.2019.0259 |
container_title |
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences |
container_volume |
475 |
container_issue |
2228 |
container_start_page |
20190259 |
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1800752087007494144 |