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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ftboisestateu:oai:scholarworks.boisestate.edu:cgiss_facpubs-1042 2023-10-29T02:36:28+01:00 Air Compression as a Mechanism for the Underdamped Slug Test Response in Fractured Glacier Ice Meierbachtol, Toby W. Harper, Joel T. Humphrey, Neil F. Shaha, Jeremy Bradford, John H. 2008-11-14T08:00:00Z application/pdf https://scholarworks.boisestate.edu/cgiss_facpubs/43 https://scholarworks.boisestate.edu/context/cgiss_facpubs/article/1042/viewcontent/Bradford___Air_compression.pdf unknown ScholarWorks https://scholarworks.boisestate.edu/cgiss_facpubs/43 https://scholarworks.boisestate.edu/context/cgiss_facpubs/article/1042/viewcontent/Bradford___Air_compression.pdf Copyright 2008 by the American Geophysical Union. DOI: 10.1029/2007JF000908 CGISS Publications and Presentations glaciology subglacial hydrology slug test Geosciences Earth Sciences Geophysics and Seismology text 2008 ftboisestateu 2023-09-29T15:03:39Z 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 Boise State University: Scholar Works |
institution |
Open Polar |
collection |
Boise State University: Scholar Works |
op_collection_id |
ftboisestateu |
language |
unknown |
topic |
glaciology subglacial hydrology slug test Geosciences Earth Sciences Geophysics and Seismology |
spellingShingle |
glaciology subglacial hydrology slug test Geosciences Earth Sciences Geophysics and Seismology Meierbachtol, Toby W. Harper, Joel T. Humphrey, Neil F. Shaha, Jeremy Bradford, John H. Air Compression as a Mechanism for the Underdamped Slug Test Response in Fractured Glacier Ice |
topic_facet |
glaciology subglacial hydrology slug test Geosciences Earth Sciences Geophysics and Seismology |
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 F. Shaha, Jeremy Bradford, John H. |
author_facet |
Meierbachtol, Toby W. Harper, Joel T. Humphrey, Neil F. Shaha, Jeremy Bradford, John H. |
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 |
publishDate |
2008 |
url |
https://scholarworks.boisestate.edu/cgiss_facpubs/43 https://scholarworks.boisestate.edu/context/cgiss_facpubs/article/1042/viewcontent/Bradford___Air_compression.pdf |
genre |
glacier Alaska |
genre_facet |
glacier Alaska |
op_source |
CGISS Publications and Presentations |
op_relation |
https://scholarworks.boisestate.edu/cgiss_facpubs/43 https://scholarworks.boisestate.edu/context/cgiss_facpubs/article/1042/viewcontent/Bradford___Air_compression.pdf |
op_rights |
Copyright 2008 by the American Geophysical Union. DOI: 10.1029/2007JF000908 |
_version_ |
1781060416737116160 |