Near-Surface Internal Melting: a Substantial Mass Loss on Antarctic Dry Valley Glaciers
The McMurdo Dry Valleys, southern Victoria Land, East Antarctica, are a polar desert, and melt from glacial ice is the primary source of water to streams, lakes and associated ecosystems. Previous work found that to adequately model glacier ablation and subsurface ice temperatures with a surface ene...
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ftportlandstate:oai:pdxscholar.library.pdx.edu:geology_fac-1048 2023-05-15T13:58:46+02:00 Near-Surface Internal Melting: a Substantial Mass Loss on Antarctic Dry Valley Glaciers Hoffman, Matthew J. Fountain, Andrew G. Liston, Glen E. 2014-04-01T07:00:00Z application/pdf https://pdxscholar.library.pdx.edu/geology_fac/49 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1048&context=geology_fac unknown PDXScholar https://pdxscholar.library.pdx.edu/geology_fac/49 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1048&context=geology_fac Geology Faculty Publications and Presentations Meltwater -- Antarctica -- McMurdo Dry Valleys Glaciers -- Antarctica -- McMurdo Dry Valleys Ablation (Aerothermodynamics) Geology Glaciology Physical and Environmental Geography text 2014 ftportlandstate 2022-01-09T19:31:23Z The McMurdo Dry Valleys, southern Victoria Land, East Antarctica, are a polar desert, and melt from glacial ice is the primary source of water to streams, lakes and associated ecosystems. Previous work found that to adequately model glacier ablation and subsurface ice temperatures with a surface energy-balance model required including the transmission of solar radiation into the ice. Here we investigate the contribution of subsurface melt to the mass balance of (and runoff from) Dry Valley glaciers by including a drainage process in the model and applying the model to three glacier sites using 13years of hourly meteorological data. Model results for the smooth glacier surfaces common to many glaciers in the Dry Valleys showed that sublimation was typically the largest component of surface lowering, with rare episodes of surface melting, consistent with anecdotal field observations. Results also showed extensive internal melting 5-15 cm below the ice surface, the drainage of which accounted for 50% of summer ablation. This is consistent with field observations of subsurface streams and formation of a weathering crust. We identify an annual cycle of weathering crust formation in summer and its removal during the 10 months of winter sublimation. Text Antarc* Antarctic Antarctica East Antarctica McMurdo Dry Valleys polar desert Victoria Land Portland State University: PDXScholar Antarctic East Antarctica McMurdo Dry Valleys Victoria Land |
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Portland State University: PDXScholar |
op_collection_id |
ftportlandstate |
language |
unknown |
topic |
Meltwater -- Antarctica -- McMurdo Dry Valleys Glaciers -- Antarctica -- McMurdo Dry Valleys Ablation (Aerothermodynamics) Geology Glaciology Physical and Environmental Geography |
spellingShingle |
Meltwater -- Antarctica -- McMurdo Dry Valleys Glaciers -- Antarctica -- McMurdo Dry Valleys Ablation (Aerothermodynamics) Geology Glaciology Physical and Environmental Geography Hoffman, Matthew J. Fountain, Andrew G. Liston, Glen E. Near-Surface Internal Melting: a Substantial Mass Loss on Antarctic Dry Valley Glaciers |
topic_facet |
Meltwater -- Antarctica -- McMurdo Dry Valleys Glaciers -- Antarctica -- McMurdo Dry Valleys Ablation (Aerothermodynamics) Geology Glaciology Physical and Environmental Geography |
description |
The McMurdo Dry Valleys, southern Victoria Land, East Antarctica, are a polar desert, and melt from glacial ice is the primary source of water to streams, lakes and associated ecosystems. Previous work found that to adequately model glacier ablation and subsurface ice temperatures with a surface energy-balance model required including the transmission of solar radiation into the ice. Here we investigate the contribution of subsurface melt to the mass balance of (and runoff from) Dry Valley glaciers by including a drainage process in the model and applying the model to three glacier sites using 13years of hourly meteorological data. Model results for the smooth glacier surfaces common to many glaciers in the Dry Valleys showed that sublimation was typically the largest component of surface lowering, with rare episodes of surface melting, consistent with anecdotal field observations. Results also showed extensive internal melting 5-15 cm below the ice surface, the drainage of which accounted for 50% of summer ablation. This is consistent with field observations of subsurface streams and formation of a weathering crust. We identify an annual cycle of weathering crust formation in summer and its removal during the 10 months of winter sublimation. |
format |
Text |
author |
Hoffman, Matthew J. Fountain, Andrew G. Liston, Glen E. |
author_facet |
Hoffman, Matthew J. Fountain, Andrew G. Liston, Glen E. |
author_sort |
Hoffman, Matthew J. |
title |
Near-Surface Internal Melting: a Substantial Mass Loss on Antarctic Dry Valley Glaciers |
title_short |
Near-Surface Internal Melting: a Substantial Mass Loss on Antarctic Dry Valley Glaciers |
title_full |
Near-Surface Internal Melting: a Substantial Mass Loss on Antarctic Dry Valley Glaciers |
title_fullStr |
Near-Surface Internal Melting: a Substantial Mass Loss on Antarctic Dry Valley Glaciers |
title_full_unstemmed |
Near-Surface Internal Melting: a Substantial Mass Loss on Antarctic Dry Valley Glaciers |
title_sort |
near-surface internal melting: a substantial mass loss on antarctic dry valley glaciers |
publisher |
PDXScholar |
publishDate |
2014 |
url |
https://pdxscholar.library.pdx.edu/geology_fac/49 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1048&context=geology_fac |
geographic |
Antarctic East Antarctica McMurdo Dry Valleys Victoria Land |
geographic_facet |
Antarctic East Antarctica McMurdo Dry Valleys Victoria Land |
genre |
Antarc* Antarctic Antarctica East Antarctica McMurdo Dry Valleys polar desert Victoria Land |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica McMurdo Dry Valleys polar desert Victoria Land |
op_source |
Geology Faculty Publications and Presentations |
op_relation |
https://pdxscholar.library.pdx.edu/geology_fac/49 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1048&context=geology_fac |
_version_ |
1766267107110027264 |