Water Flow at the Base of a Surging Glacier
Water tracing experiments were successfully conducted over a distance of ten kilometers along the base of Variegated Glacier for the purpose of characterizing the water drainage system of the glacier in the surging as compared to the non-surging state. Three tracing experiments were conducted, and f...
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ftdatacite:10.7907/vshg-g674 2023-05-15T16:20:29+02:00 Water Flow at the Base of a Surging Glacier Brugman, Melinda Mary 1987 PDF https://dx.doi.org/10.7907/vshg-g674 https://resolver.caltech.edu/CaltechETD:etd-07192006-093757 en eng California Institute of Technology No commercial reproduction, distribution, display or performance rights in this work are provided. water methanol floating Alaska basal mannings sediment storage Rhodamine outburst extraction survey roughness Yakutat glacier tracking base model galloping turbidity calibration hydrology dye Tinopal fluorescent linked pressure PPB instability cavity rapid channels WT flow exponential Surge Geology FOS Earth and related environmental sciences cavity-conduit floculation Thesis Text Dissertation thesis 1987 ftdatacite https://doi.org/10.7907/vshg-g674 2021-11-05T12:55:41Z Water tracing experiments were successfully conducted over a distance of ten kilometers along the base of Variegated Glacier for the purpose of characterizing the water drainage system of the glacier in the surging as compared to the non-surging state. Three tracing experiments were conducted, and fluorescent dyes, Rhodamine WT and Tinopal AMS, were injected into boreholes at separate locations. The two Rhodamine WT experiments were conducted over a 10 km distance, both during the most rapid surging motion of the glacier, and after its cessation. In each experiment, the terminus streams were monitored for stream discharge, sediment content and tracer concentration. Rhodamine WT tracer was significantly adsorbed on the suspended sediment, particularly during the surge. The adsorption behavior followed the Langmuir model, and calculated distribution coefficients of Kd = 100 to 1000 ml/g were measured for during the glacier surge. The Kd values measured after the surge were lower than during the surge by a factor of 10 to 1000. The much higher Kd values in the surging as compared to non-surging glacier states can be best explained by a factor of 10 to 1000 decrease in the modal and/or mean grain-size of the suspended sediment. The abundance of fine-grained sediment during the surge is probably due to increased grinding of rock material at the glacier bed. Theoretical models of tracer dispersion in a single tunnel, were compared to models of dispersion in linked-cavity systems to infer the details of water flow at the glacier bed. The broad, roughly symmetrical, dye-return curve measured during the glacier surge conforms to diffusive dispersion theory, and differs sharply from the highly asymmetrical dispersion curve measured after the surge. Results indicate the dispersion behavior, and calculated Manning roughness, of the post-surge Variegated Glacier is similar to those of glaciers that do not surge. The drainage system of the Variegated Glacier in the surging state is consistent with a model of tracer dispersion in an interconnecting network of conduits and cavities, and is strikingly different from the tunnel system indicated for the non-surging state. Thesis glacier glaciers Yakutat Alaska DataCite Metadata Store (German National Library of Science and Technology) Langmuir ENVELOPE(-67.150,-67.150,-66.967,-66.967) |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
water methanol floating Alaska basal mannings sediment storage Rhodamine outburst extraction survey roughness Yakutat glacier tracking base model galloping turbidity calibration hydrology dye Tinopal fluorescent linked pressure PPB instability cavity rapid channels WT flow exponential Surge Geology FOS Earth and related environmental sciences cavity-conduit floculation |
spellingShingle |
water methanol floating Alaska basal mannings sediment storage Rhodamine outburst extraction survey roughness Yakutat glacier tracking base model galloping turbidity calibration hydrology dye Tinopal fluorescent linked pressure PPB instability cavity rapid channels WT flow exponential Surge Geology FOS Earth and related environmental sciences cavity-conduit floculation Brugman, Melinda Mary Water Flow at the Base of a Surging Glacier |
topic_facet |
water methanol floating Alaska basal mannings sediment storage Rhodamine outburst extraction survey roughness Yakutat glacier tracking base model galloping turbidity calibration hydrology dye Tinopal fluorescent linked pressure PPB instability cavity rapid channels WT flow exponential Surge Geology FOS Earth and related environmental sciences cavity-conduit floculation |
description |
Water tracing experiments were successfully conducted over a distance of ten kilometers along the base of Variegated Glacier for the purpose of characterizing the water drainage system of the glacier in the surging as compared to the non-surging state. Three tracing experiments were conducted, and fluorescent dyes, Rhodamine WT and Tinopal AMS, were injected into boreholes at separate locations. The two Rhodamine WT experiments were conducted over a 10 km distance, both during the most rapid surging motion of the glacier, and after its cessation. In each experiment, the terminus streams were monitored for stream discharge, sediment content and tracer concentration. Rhodamine WT tracer was significantly adsorbed on the suspended sediment, particularly during the surge. The adsorption behavior followed the Langmuir model, and calculated distribution coefficients of Kd = 100 to 1000 ml/g were measured for during the glacier surge. The Kd values measured after the surge were lower than during the surge by a factor of 10 to 1000. The much higher Kd values in the surging as compared to non-surging glacier states can be best explained by a factor of 10 to 1000 decrease in the modal and/or mean grain-size of the suspended sediment. The abundance of fine-grained sediment during the surge is probably due to increased grinding of rock material at the glacier bed. Theoretical models of tracer dispersion in a single tunnel, were compared to models of dispersion in linked-cavity systems to infer the details of water flow at the glacier bed. The broad, roughly symmetrical, dye-return curve measured during the glacier surge conforms to diffusive dispersion theory, and differs sharply from the highly asymmetrical dispersion curve measured after the surge. Results indicate the dispersion behavior, and calculated Manning roughness, of the post-surge Variegated Glacier is similar to those of glaciers that do not surge. The drainage system of the Variegated Glacier in the surging state is consistent with a model of tracer dispersion in an interconnecting network of conduits and cavities, and is strikingly different from the tunnel system indicated for the non-surging state. |
format |
Thesis |
author |
Brugman, Melinda Mary |
author_facet |
Brugman, Melinda Mary |
author_sort |
Brugman, Melinda Mary |
title |
Water Flow at the Base of a Surging Glacier |
title_short |
Water Flow at the Base of a Surging Glacier |
title_full |
Water Flow at the Base of a Surging Glacier |
title_fullStr |
Water Flow at the Base of a Surging Glacier |
title_full_unstemmed |
Water Flow at the Base of a Surging Glacier |
title_sort |
water flow at the base of a surging glacier |
publisher |
California Institute of Technology |
publishDate |
1987 |
url |
https://dx.doi.org/10.7907/vshg-g674 https://resolver.caltech.edu/CaltechETD:etd-07192006-093757 |
long_lat |
ENVELOPE(-67.150,-67.150,-66.967,-66.967) |
geographic |
Langmuir |
geographic_facet |
Langmuir |
genre |
glacier glaciers Yakutat Alaska |
genre_facet |
glacier glaciers Yakutat Alaska |
op_rights |
No commercial reproduction, distribution, display or performance rights in this work are provided. |
op_doi |
https://doi.org/10.7907/vshg-g674 |
_version_ |
1766008410130612224 |