Diurnal fluctuations in borehole water levels: configuration of the drainage system beneath Bench Glacier, Alaska, USA
ABSTRACT. Water levels were measured in boreholes spaced along the entire length of Bench Glacier, Alaska, USA, for a period in excess of 2 years. Instrumented boreholes were arranged as nine pairs along the center line of the glacier and an orthogonal grid of 16 boreholes in a 3600 m 2 region at th...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.429.9265 2023-05-15T16:20:25+02:00 Diurnal fluctuations in borehole water levels: configuration of the drainage system beneath Bench Glacier, Alaska, USA T. J. Fudge Neil F. Humphrey Joel T. Harper W. Tad Pfeffer The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.429.9265 http://www.igsoc.org/journal/54/185/j07j022.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.429.9265 http://www.igsoc.org/journal/54/185/j07j022.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.igsoc.org/journal/54/185/j07j022.pdf text ftciteseerx 2016-01-08T04:33:17Z ABSTRACT. Water levels were measured in boreholes spaced along the entire length of Bench Glacier, Alaska, USA, for a period in excess of 2 years. Instrumented boreholes were arranged as nine pairs along the center line of the glacier and an orthogonal grid of 16 boreholes in a 3600 m 2 region at the center of the ablation area. Diurnal fluctuations of the water levels were found to be restricted to the late melt season. Pairs of boreholes spaced along the length of the ablation area often exhibited similar fluctuations and diurnal changes in water levels. Three distinct and independent types of diurnal fluctuations in water level were observed in clusters of boreholes within the grid of boreholes. Head gradients suggest water did not flow between clusters, and a single tunnel connecting the boreholes could not explain the observed pattern of diurnal water-level fluctuations. Inter-borehole and boreholecluster connectivity suggests the cross-glacier width of influence of a segment of the drainage system connected to a borehole was limited to tens of meters. A drainage configuration whereby boreholes are connected to a somewhat distant tunnel by drainage pipes of differing lengths, often hundreds of meters, is shown with a numerical test to be a plausible explanation for the observed borehole behavior. Text glacier Alaska Unknown |
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Open Polar |
collection |
Unknown |
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ftciteseerx |
language |
English |
description |
ABSTRACT. Water levels were measured in boreholes spaced along the entire length of Bench Glacier, Alaska, USA, for a period in excess of 2 years. Instrumented boreholes were arranged as nine pairs along the center line of the glacier and an orthogonal grid of 16 boreholes in a 3600 m 2 region at the center of the ablation area. Diurnal fluctuations of the water levels were found to be restricted to the late melt season. Pairs of boreholes spaced along the length of the ablation area often exhibited similar fluctuations and diurnal changes in water levels. Three distinct and independent types of diurnal fluctuations in water level were observed in clusters of boreholes within the grid of boreholes. Head gradients suggest water did not flow between clusters, and a single tunnel connecting the boreholes could not explain the observed pattern of diurnal water-level fluctuations. Inter-borehole and boreholecluster connectivity suggests the cross-glacier width of influence of a segment of the drainage system connected to a borehole was limited to tens of meters. A drainage configuration whereby boreholes are connected to a somewhat distant tunnel by drainage pipes of differing lengths, often hundreds of meters, is shown with a numerical test to be a plausible explanation for the observed borehole behavior. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
T. J. Fudge Neil F. Humphrey Joel T. Harper W. Tad Pfeffer |
spellingShingle |
T. J. Fudge Neil F. Humphrey Joel T. Harper W. Tad Pfeffer Diurnal fluctuations in borehole water levels: configuration of the drainage system beneath Bench Glacier, Alaska, USA |
author_facet |
T. J. Fudge Neil F. Humphrey Joel T. Harper W. Tad Pfeffer |
author_sort |
T. J. Fudge |
title |
Diurnal fluctuations in borehole water levels: configuration of the drainage system beneath Bench Glacier, Alaska, USA |
title_short |
Diurnal fluctuations in borehole water levels: configuration of the drainage system beneath Bench Glacier, Alaska, USA |
title_full |
Diurnal fluctuations in borehole water levels: configuration of the drainage system beneath Bench Glacier, Alaska, USA |
title_fullStr |
Diurnal fluctuations in borehole water levels: configuration of the drainage system beneath Bench Glacier, Alaska, USA |
title_full_unstemmed |
Diurnal fluctuations in borehole water levels: configuration of the drainage system beneath Bench Glacier, Alaska, USA |
title_sort |
diurnal fluctuations in borehole water levels: configuration of the drainage system beneath bench glacier, alaska, usa |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.429.9265 http://www.igsoc.org/journal/54/185/j07j022.pdf |
genre |
glacier Alaska |
genre_facet |
glacier Alaska |
op_source |
http://www.igsoc.org/journal/54/185/j07j022.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.429.9265 http://www.igsoc.org/journal/54/185/j07j022.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766008332817006592 |