The evolution of isolated cavities and hydraulic connection at the glacier bed – Part 1: Steady states and friction laws
Models of subglacial drainage and of cavity formation generally assume that the glacier bed is pervasively hydraulically connected. A growing body of field observations indicates that this assumption is frequently violated in practice. In this paper, I use an extension of existing models of steady-s...
Published in: | The Cryosphere |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2023
|
Subjects: | |
Online Access: | https://doi.org/10.5194/tc-17-4797-2023 https://doaj.org/article/9475592bab55476397c51159322ce5de |
id |
ftdoajarticles:oai:doaj.org/article:9475592bab55476397c51159322ce5de |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:9475592bab55476397c51159322ce5de 2023-12-31T10:23:39+01:00 The evolution of isolated cavities and hydraulic connection at the glacier bed – Part 1: Steady states and friction laws C. Schoof 2023-11-01T00:00:00Z https://doi.org/10.5194/tc-17-4797-2023 https://doaj.org/article/9475592bab55476397c51159322ce5de EN eng Copernicus Publications https://tc.copernicus.org/articles/17/4797/2023/tc-17-4797-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-4797-2023 1994-0416 1994-0424 https://doaj.org/article/9475592bab55476397c51159322ce5de The Cryosphere, Vol 17, Pp 4797-4815 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-4797-2023 2023-12-03T01:39:04Z Models of subglacial drainage and of cavity formation generally assume that the glacier bed is pervasively hydraulically connected. A growing body of field observations indicates that this assumption is frequently violated in practice. In this paper, I use an extension of existing models of steady-state cavitation to study the formation of hydraulically isolated, uncavitated, low-pressure regions of the bed, which would become flooded if they had access to the subglacial drainage system. I also study their natural counterpart, hydraulically isolated cavities that would drain if they had access to the subglacial drainage system. I show that connections to the drainage system are made at two different sets of critical effective pressure, a lower one at which uncavitated low-pressure regions connect to the drainage system and a higher one at which isolated cavities do the same. I also show that the extent of cavitation, determined by the history of connections made at the bed, has a dominant effect on basal drag while remaining outside the realm of previously employed basal friction laws: changes in basal effective pressure alone may have a minor effect on basal drag until a connection between a cavity and an uncavitated low-pressure region of the bed is made, at which point a drastic and irreversible drop in drag occurs. These results point to the need to expand basal friction and drainage models to include a description of basal connectivity. Article in Journal/Newspaper The Cryosphere Directory of Open Access Journals: DOAJ Articles The Cryosphere 17 11 4797 4815 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 C. Schoof The evolution of isolated cavities and hydraulic connection at the glacier bed – Part 1: Steady states and friction laws |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Models of subglacial drainage and of cavity formation generally assume that the glacier bed is pervasively hydraulically connected. A growing body of field observations indicates that this assumption is frequently violated in practice. In this paper, I use an extension of existing models of steady-state cavitation to study the formation of hydraulically isolated, uncavitated, low-pressure regions of the bed, which would become flooded if they had access to the subglacial drainage system. I also study their natural counterpart, hydraulically isolated cavities that would drain if they had access to the subglacial drainage system. I show that connections to the drainage system are made at two different sets of critical effective pressure, a lower one at which uncavitated low-pressure regions connect to the drainage system and a higher one at which isolated cavities do the same. I also show that the extent of cavitation, determined by the history of connections made at the bed, has a dominant effect on basal drag while remaining outside the realm of previously employed basal friction laws: changes in basal effective pressure alone may have a minor effect on basal drag until a connection between a cavity and an uncavitated low-pressure region of the bed is made, at which point a drastic and irreversible drop in drag occurs. These results point to the need to expand basal friction and drainage models to include a description of basal connectivity. |
format |
Article in Journal/Newspaper |
author |
C. Schoof |
author_facet |
C. Schoof |
author_sort |
C. Schoof |
title |
The evolution of isolated cavities and hydraulic connection at the glacier bed – Part 1: Steady states and friction laws |
title_short |
The evolution of isolated cavities and hydraulic connection at the glacier bed – Part 1: Steady states and friction laws |
title_full |
The evolution of isolated cavities and hydraulic connection at the glacier bed – Part 1: Steady states and friction laws |
title_fullStr |
The evolution of isolated cavities and hydraulic connection at the glacier bed – Part 1: Steady states and friction laws |
title_full_unstemmed |
The evolution of isolated cavities and hydraulic connection at the glacier bed – Part 1: Steady states and friction laws |
title_sort |
evolution of isolated cavities and hydraulic connection at the glacier bed – part 1: steady states and friction laws |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-4797-2023 https://doaj.org/article/9475592bab55476397c51159322ce5de |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 17, Pp 4797-4815 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/4797/2023/tc-17-4797-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-4797-2023 1994-0416 1994-0424 https://doaj.org/article/9475592bab55476397c51159322ce5de |
op_doi |
https://doi.org/10.5194/tc-17-4797-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
11 |
container_start_page |
4797 |
op_container_end_page |
4815 |
_version_ |
1786835393788772352 |