Air compression as a mechanism for the underdamped slug test response in fractured glacier ice
Artificial perturbations of borehole water levels, known as slug tests, are a useful means of characterizing the glacier hydrologic system. Slug tests were performed on Bench Glacier, Alaska, in 21 boreholes over three field seasons during the transition from a winter to a summer drainage mode. Fift...
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ScholarWorks at University of Montana
2008
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Online Access: | https://scholarworks.umt.edu/geosci_pubs/11 https://doi.org/10.1029/2007JF000908 https://scholarworks.umt.edu/context/geosci_pubs/article/1019/viewcontent/Meierbachtol_et_al_2008_Journal_of_Geophysical_Research__Earth_Surface__2003_2012_.pdf https://scholarworks.umt.edu/context/geosci_pubs/article/1019/filename/0/type/additional/viewcontent/Air_Compression_as_a_mechanism_for_the_underdamped_slug_test_response_in_fractured_glacier_ice.pdf |
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ftunivmontana:oai:scholarworks.umt.edu:geosci_pubs-1019 2023-07-16T03:58:33+02:00 Air compression as a mechanism for the underdamped slug test response in fractured glacier ice Meierbachtol, Toby W. Harper, Joel T. Humphrey, Neil Shaha, Jeremy Bradford, John 2008-11-14T08:00:00Z application/pdf https://scholarworks.umt.edu/geosci_pubs/11 https://doi.org/10.1029/2007JF000908 https://scholarworks.umt.edu/context/geosci_pubs/article/1019/viewcontent/Meierbachtol_et_al_2008_Journal_of_Geophysical_Research__Earth_Surface__2003_2012_.pdf https://scholarworks.umt.edu/context/geosci_pubs/article/1019/filename/0/type/additional/viewcontent/Air_Compression_as_a_mechanism_for_the_underdamped_slug_test_response_in_fractured_glacier_ice.pdf unknown ScholarWorks at University of Montana https://scholarworks.umt.edu/geosci_pubs/11 doi:10.1029/2007JF000908 https://scholarworks.umt.edu/context/geosci_pubs/article/1019/viewcontent/Meierbachtol_et_al_2008_Journal_of_Geophysical_Research__Earth_Surface__2003_2012_.pdf https://scholarworks.umt.edu/context/geosci_pubs/article/1019/filename/0/type/additional/viewcontent/Air_Compression_as_a_mechanism_for_the_underdamped_slug_test_response_in_fractured_glacier_ice.pdf © 2008 by the American Geophysical Union. Geosciences Faculty Publications Earth Sciences Geology text 2008 ftunivmontana https://doi.org/10.1029/2007JF000908 2023-06-27T22:19:01Z Artificial perturbations of borehole water levels, known as slug tests, are a useful means of characterizing the glacier hydrologic system. Slug tests were performed on Bench Glacier, Alaska, in 21 boreholes over three field seasons during the transition from a winter to a summer drainage mode. Fifty-four slug tests were conducted, with water level monitoring in up to five boreholes adjacent to the slugged borehole. Seven of the slug tests were performed in conjunction with dye dispersion tests to identify water pathways within the slugged borehole following perturbation. Nearly 60% of monitored adjacent boreholes showed a hydraulic connection to the slugged borehole via the glacier bed. The nature and degree of connectivity was temporally variable, suggesting that the drainage network at the bed was highly dynamic on a daily timescale and spatial scale of tens of meters. The variability of slug test responses over time and space limit the feasibility of six alternative explanations for the oscillatory water level behavior characteristic of the underdamped response. We propose a seventh, that is, that coherent air packages are a reasonable means of producing the compliance needed to generate the underdamped slug test responses on Bench Glacier, and that these air packages may exist within the glacier at the tips of subglacially propagated fractures. Text glacier Alaska University of Montana: ScholarWorks Journal of Geophysical Research 113 F4 |
institution |
Open Polar |
collection |
University of Montana: ScholarWorks |
op_collection_id |
ftunivmontana |
language |
unknown |
topic |
Earth Sciences Geology |
spellingShingle |
Earth Sciences Geology Meierbachtol, Toby W. Harper, Joel T. Humphrey, Neil Shaha, Jeremy Bradford, John Air compression as a mechanism for the underdamped slug test response in fractured glacier ice |
topic_facet |
Earth Sciences Geology |
description |
Artificial perturbations of borehole water levels, known as slug tests, are a useful means of characterizing the glacier hydrologic system. Slug tests were performed on Bench Glacier, Alaska, in 21 boreholes over three field seasons during the transition from a winter to a summer drainage mode. Fifty-four slug tests were conducted, with water level monitoring in up to five boreholes adjacent to the slugged borehole. Seven of the slug tests were performed in conjunction with dye dispersion tests to identify water pathways within the slugged borehole following perturbation. Nearly 60% of monitored adjacent boreholes showed a hydraulic connection to the slugged borehole via the glacier bed. The nature and degree of connectivity was temporally variable, suggesting that the drainage network at the bed was highly dynamic on a daily timescale and spatial scale of tens of meters. The variability of slug test responses over time and space limit the feasibility of six alternative explanations for the oscillatory water level behavior characteristic of the underdamped response. We propose a seventh, that is, that coherent air packages are a reasonable means of producing the compliance needed to generate the underdamped slug test responses on Bench Glacier, and that these air packages may exist within the glacier at the tips of subglacially propagated fractures. |
format |
Text |
author |
Meierbachtol, Toby W. Harper, Joel T. Humphrey, Neil Shaha, Jeremy Bradford, John |
author_facet |
Meierbachtol, Toby W. Harper, Joel T. Humphrey, Neil Shaha, Jeremy Bradford, John |
author_sort |
Meierbachtol, Toby W. |
title |
Air compression as a mechanism for the underdamped slug test response in fractured glacier ice |
title_short |
Air compression as a mechanism for the underdamped slug test response in fractured glacier ice |
title_full |
Air compression as a mechanism for the underdamped slug test response in fractured glacier ice |
title_fullStr |
Air compression as a mechanism for the underdamped slug test response in fractured glacier ice |
title_full_unstemmed |
Air compression as a mechanism for the underdamped slug test response in fractured glacier ice |
title_sort |
air compression as a mechanism for the underdamped slug test response in fractured glacier ice |
publisher |
ScholarWorks at University of Montana |
publishDate |
2008 |
url |
https://scholarworks.umt.edu/geosci_pubs/11 https://doi.org/10.1029/2007JF000908 https://scholarworks.umt.edu/context/geosci_pubs/article/1019/viewcontent/Meierbachtol_et_al_2008_Journal_of_Geophysical_Research__Earth_Surface__2003_2012_.pdf https://scholarworks.umt.edu/context/geosci_pubs/article/1019/filename/0/type/additional/viewcontent/Air_Compression_as_a_mechanism_for_the_underdamped_slug_test_response_in_fractured_glacier_ice.pdf |
genre |
glacier Alaska |
genre_facet |
glacier Alaska |
op_source |
Geosciences Faculty Publications |
op_relation |
https://scholarworks.umt.edu/geosci_pubs/11 doi:10.1029/2007JF000908 https://scholarworks.umt.edu/context/geosci_pubs/article/1019/viewcontent/Meierbachtol_et_al_2008_Journal_of_Geophysical_Research__Earth_Surface__2003_2012_.pdf https://scholarworks.umt.edu/context/geosci_pubs/article/1019/filename/0/type/additional/viewcontent/Air_Compression_as_a_mechanism_for_the_underdamped_slug_test_response_in_fractured_glacier_ice.pdf |
op_rights |
© 2008 by the American Geophysical Union. |
op_doi |
https://doi.org/10.1029/2007JF000908 |
container_title |
Journal of Geophysical Research |
container_volume |
113 |
container_issue |
F4 |
_version_ |
1771545700075569152 |