Estimation of subglacial hydraulic properties from induced changes in basal water pressure: a theoretical framework for borehole-response tests
Abstract In this paper we develop a theoretical model describing water motion in a coupled borehole-subglacial flow system. The theory applies to basal drainage systems having multiple and extensive interconnected flow paths. Within this domain it encompasses a broad range of flow regimes, from lami...
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Language: | English |
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Cambridge University Press (CUP)
1993
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Online Access: | http://dx.doi.org/10.1017/s0022143000015999 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015999 |
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crcambridgeupr:10.1017/s0022143000015999 2024-03-03T08:44:41+00:00 Estimation of subglacial hydraulic properties from induced changes in basal water pressure: a theoretical framework for borehole-response tests Stone, Dan B. Clarke, Garry K.C. 1993 http://dx.doi.org/10.1017/s0022143000015999 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015999 en eng Cambridge University Press (CUP) Journal of Glaciology volume 39, issue 132, page 327-340 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1993 crcambridgeupr https://doi.org/10.1017/s0022143000015999 2024-02-08T08:41:37Z Abstract In this paper we develop a theoretical model describing water motion in a coupled borehole-subglacial flow system. The theory applies to basal drainage systems having multiple and extensive interconnected flow paths. Within this domain it encompasses a broad range of flow regimes, from laminar Darcian flow in a thick permeable unit to turbulent sheet flow in a very thin layer. Important terms in the model are highlighted by recasting the problem in dimensionless form. The non-dimensional formulation indicates that there are four free parameters in the coupled system. These parameters characterize skin friction in the borehole, and diffusion, transmissivity and turbulent transport in the subglacial flow layer. Dimensionless results show that, under most circumstances, the effects of skin friction in the borehole are negligible. Diffusion, transmissivity and especially turbulent transport in the basal layer are found to influence subglacial water flow strongly. We use our model to predict fluctuations of borehole-water levels that result from different types of disturbances. We show how this framework can be used to estimate subglacial hydraulic properties by comparing model results with data collected during field experiments on Trapridge Glacier, Yukon Territory, Canada in 1989 and 1990. Article in Journal/Newspaper glacier* Journal of Glaciology Yukon Cambridge University Press Yukon Canada Trapridge Glacier ENVELOPE(-140.337,-140.337,61.233,61.233) Journal of Glaciology 39 132 327 340 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Stone, Dan B. Clarke, Garry K.C. Estimation of subglacial hydraulic properties from induced changes in basal water pressure: a theoretical framework for borehole-response tests |
topic_facet |
Earth-Surface Processes |
description |
Abstract In this paper we develop a theoretical model describing water motion in a coupled borehole-subglacial flow system. The theory applies to basal drainage systems having multiple and extensive interconnected flow paths. Within this domain it encompasses a broad range of flow regimes, from laminar Darcian flow in a thick permeable unit to turbulent sheet flow in a very thin layer. Important terms in the model are highlighted by recasting the problem in dimensionless form. The non-dimensional formulation indicates that there are four free parameters in the coupled system. These parameters characterize skin friction in the borehole, and diffusion, transmissivity and turbulent transport in the subglacial flow layer. Dimensionless results show that, under most circumstances, the effects of skin friction in the borehole are negligible. Diffusion, transmissivity and especially turbulent transport in the basal layer are found to influence subglacial water flow strongly. We use our model to predict fluctuations of borehole-water levels that result from different types of disturbances. We show how this framework can be used to estimate subglacial hydraulic properties by comparing model results with data collected during field experiments on Trapridge Glacier, Yukon Territory, Canada in 1989 and 1990. |
format |
Article in Journal/Newspaper |
author |
Stone, Dan B. Clarke, Garry K.C. |
author_facet |
Stone, Dan B. Clarke, Garry K.C. |
author_sort |
Stone, Dan B. |
title |
Estimation of subglacial hydraulic properties from induced changes in basal water pressure: a theoretical framework for borehole-response tests |
title_short |
Estimation of subglacial hydraulic properties from induced changes in basal water pressure: a theoretical framework for borehole-response tests |
title_full |
Estimation of subglacial hydraulic properties from induced changes in basal water pressure: a theoretical framework for borehole-response tests |
title_fullStr |
Estimation of subglacial hydraulic properties from induced changes in basal water pressure: a theoretical framework for borehole-response tests |
title_full_unstemmed |
Estimation of subglacial hydraulic properties from induced changes in basal water pressure: a theoretical framework for borehole-response tests |
title_sort |
estimation of subglacial hydraulic properties from induced changes in basal water pressure: a theoretical framework for borehole-response tests |
publisher |
Cambridge University Press (CUP) |
publishDate |
1993 |
url |
http://dx.doi.org/10.1017/s0022143000015999 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015999 |
long_lat |
ENVELOPE(-140.337,-140.337,61.233,61.233) |
geographic |
Yukon Canada Trapridge Glacier |
geographic_facet |
Yukon Canada Trapridge Glacier |
genre |
glacier* Journal of Glaciology Yukon |
genre_facet |
glacier* Journal of Glaciology Yukon |
op_source |
Journal of Glaciology volume 39, issue 132, page 327-340 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000015999 |
container_title |
Journal of Glaciology |
container_volume |
39 |
container_issue |
132 |
container_start_page |
327 |
op_container_end_page |
340 |
_version_ |
1792500166340640768 |