Detailed Spatially Distributed Geothermal Heat-flow Data for Modeling of Basal Temperatures and Meltwater Production Beneath the Fennoscandian Ice Sheet
Accurate modeling of ice sheets requires proper information on boundary conditions, including the geothermal heat flow (or heat-flow density (HFD)). Traditionally, one uniform HFD value is adopted for the entire modeled domain. We have calculated a distributed, high-resolution HFD dataset for an app...
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ScholarWorks at University of Montana
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ftunivmontana:oai:scholarworks.umt.edu:cs_pubs-1000 2023-07-16T03:52:24+02:00 Detailed Spatially Distributed Geothermal Heat-flow Data for Modeling of Basal Temperatures and Meltwater Production Beneath the Fennoscandian Ice Sheet Näslund, Jens-Ove Jansson, Peter Fastook, James L. Johnson, Jesse Andersson, Leif 2004-01-01T08:00:00Z application/pdf https://scholarworks.umt.edu/cs_pubs/5 https://doi.org/10.3189/172756405781813582 https://scholarworks.umt.edu/context/cs_pubs/article/1000/viewcontent/johnson_modelingicesheet__correct_article__.pdf unknown ScholarWorks at University of Montana https://scholarworks.umt.edu/cs_pubs/5 doi:10.3189/172756405781813582 https://scholarworks.umt.edu/context/cs_pubs/article/1000/viewcontent/johnson_modelingicesheet__correct_article__.pdf Computer Science Faculty Publications Computer Sciences text 2004 ftunivmontana https://doi.org/10.3189/172756405781813582 2023-06-27T22:07:47Z Accurate modeling of ice sheets requires proper information on boundary conditions, including the geothermal heat flow (or heat-flow density (HFD)). Traditionally, one uniform HFD value is adopted for the entire modeled domain. We have calculated a distributed, high-resolution HFD dataset for an approximate core area (Sweden and Finland) of the Scandinavian ice sheet, and imbedded this within lower-resolution data published for surrounding regions. Within the Last Glacial Maximum ice margin, HFD varies with a factor of as much as 2.8 (HFD values ranging between 30 and 83mWm–2), with an average of 49mWm–2. This average value is 17% higher than 42mWm–2, a common uniform value used in ice-sheet modeling studies of Fennoscandia. Using this new distributed dataset on HFD, instead of a traditional uniform value of 42mWm–2, yields a 1.4 times larger total basal meltwater production for the last glacial cycle. Furthermore, using the new dataset in high-resolution modeling results in increased spatial thermal gradients at the bed. This enhances and introduces new local and regional effects on basal ice temperatures and melt rates. We observed significant strengthening of local ‘ice streaming’, which in one case correlates to an ice-flow event previously interpreted from geomorphology. Regional to local variations in geothermal heat flow need to be considered for proper identification and treatment of thermal and hydraulic bed conditions, most likely also when studying Laurentide, Greenland and Antarctic ice sheets. Text Antarc* Antarctic Fennoscandia Fennoscandian Greenland Ice Sheet University of Montana: ScholarWorks Antarctic Greenland Annals of Glaciology 40 95 101 |
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Open Polar |
collection |
University of Montana: ScholarWorks |
op_collection_id |
ftunivmontana |
language |
unknown |
topic |
Computer Sciences |
spellingShingle |
Computer Sciences Näslund, Jens-Ove Jansson, Peter Fastook, James L. Johnson, Jesse Andersson, Leif Detailed Spatially Distributed Geothermal Heat-flow Data for Modeling of Basal Temperatures and Meltwater Production Beneath the Fennoscandian Ice Sheet |
topic_facet |
Computer Sciences |
description |
Accurate modeling of ice sheets requires proper information on boundary conditions, including the geothermal heat flow (or heat-flow density (HFD)). Traditionally, one uniform HFD value is adopted for the entire modeled domain. We have calculated a distributed, high-resolution HFD dataset for an approximate core area (Sweden and Finland) of the Scandinavian ice sheet, and imbedded this within lower-resolution data published for surrounding regions. Within the Last Glacial Maximum ice margin, HFD varies with a factor of as much as 2.8 (HFD values ranging between 30 and 83mWm–2), with an average of 49mWm–2. This average value is 17% higher than 42mWm–2, a common uniform value used in ice-sheet modeling studies of Fennoscandia. Using this new distributed dataset on HFD, instead of a traditional uniform value of 42mWm–2, yields a 1.4 times larger total basal meltwater production for the last glacial cycle. Furthermore, using the new dataset in high-resolution modeling results in increased spatial thermal gradients at the bed. This enhances and introduces new local and regional effects on basal ice temperatures and melt rates. We observed significant strengthening of local ‘ice streaming’, which in one case correlates to an ice-flow event previously interpreted from geomorphology. Regional to local variations in geothermal heat flow need to be considered for proper identification and treatment of thermal and hydraulic bed conditions, most likely also when studying Laurentide, Greenland and Antarctic ice sheets. |
format |
Text |
author |
Näslund, Jens-Ove Jansson, Peter Fastook, James L. Johnson, Jesse Andersson, Leif |
author_facet |
Näslund, Jens-Ove Jansson, Peter Fastook, James L. Johnson, Jesse Andersson, Leif |
author_sort |
Näslund, Jens-Ove |
title |
Detailed Spatially Distributed Geothermal Heat-flow Data for Modeling of Basal Temperatures and Meltwater Production Beneath the Fennoscandian Ice Sheet |
title_short |
Detailed Spatially Distributed Geothermal Heat-flow Data for Modeling of Basal Temperatures and Meltwater Production Beneath the Fennoscandian Ice Sheet |
title_full |
Detailed Spatially Distributed Geothermal Heat-flow Data for Modeling of Basal Temperatures and Meltwater Production Beneath the Fennoscandian Ice Sheet |
title_fullStr |
Detailed Spatially Distributed Geothermal Heat-flow Data for Modeling of Basal Temperatures and Meltwater Production Beneath the Fennoscandian Ice Sheet |
title_full_unstemmed |
Detailed Spatially Distributed Geothermal Heat-flow Data for Modeling of Basal Temperatures and Meltwater Production Beneath the Fennoscandian Ice Sheet |
title_sort |
detailed spatially distributed geothermal heat-flow data for modeling of basal temperatures and meltwater production beneath the fennoscandian ice sheet |
publisher |
ScholarWorks at University of Montana |
publishDate |
2004 |
url |
https://scholarworks.umt.edu/cs_pubs/5 https://doi.org/10.3189/172756405781813582 https://scholarworks.umt.edu/context/cs_pubs/article/1000/viewcontent/johnson_modelingicesheet__correct_article__.pdf |
geographic |
Antarctic Greenland |
geographic_facet |
Antarctic Greenland |
genre |
Antarc* Antarctic Fennoscandia Fennoscandian Greenland Ice Sheet |
genre_facet |
Antarc* Antarctic Fennoscandia Fennoscandian Greenland Ice Sheet |
op_source |
Computer Science Faculty Publications |
op_relation |
https://scholarworks.umt.edu/cs_pubs/5 doi:10.3189/172756405781813582 https://scholarworks.umt.edu/context/cs_pubs/article/1000/viewcontent/johnson_modelingicesheet__correct_article__.pdf |
op_doi |
https://doi.org/10.3189/172756405781813582 |
container_title |
Annals of Glaciology |
container_volume |
40 |
container_start_page |
95 |
op_container_end_page |
101 |
_version_ |
1771545510120783872 |