Glacier-bed geomorphic processes and hydrologic conditions relevant to nuclear waste disposal
Characterizing glaciotectonic deformation, glacial erosion and sedimentation, and basal hydrologic conditions of ice sheets is vital for selecting sites for nuclear waste repositories at high latitudes. Glaciotectonic deformation is enhanced by excess pore pressures that commonly persist near ice sh...
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ftiowastateuniv:oai:lib.dr.iastate.edu:ge_at_pubs-1138 2023-05-15T13:36:09+02:00 Glacier-bed geomorphic processes and hydrologic conditions relevant to nuclear waste disposal Iverson, Neal R. Person, Mark 2012-01-01T08:00:00Z application/pdf https://lib.dr.iastate.edu/ge_at_pubs/149 https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1138&context=ge_at_pubs en eng Iowa State University Digital Repository https://lib.dr.iastate.edu/ge_at_pubs/149 https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1138&context=ge_at_pubs Creative Commons Attribution license CC-BY Geological and Atmospheric Sciences Publications erosion geomorphic glacial hydrogeology hydrology ice tectonics Geomorphology Glaciology Sedimentology Tectonics and Structure text 2012 ftiowastateuniv 2021-08-28T22:47:13Z Characterizing glaciotectonic deformation, glacial erosion and sedimentation, and basal hydrologic conditions of ice sheets is vital for selecting sites for nuclear waste repositories at high latitudes. Glaciotectonic deformation is enhanced by excess pore pressures that commonly persist near ice sheet margins. Depths of such deformation can extend locally to a few tens of meters, with depths up to approximately 300 m in exceptional cases. Rates of glacial erosion are highly variable (0.05–15 mm a−1), but ratesa−1 are expected in tectonically quiescent regions. Total erosion probably not exceeding several tens of meters is expected during a glacial cycle, although locally erosion could be greater. Consolidation of glacial sediments that is less than expected from independent estimates of glacier thickness indicates that heads at the bases of past ice sheets were usually within 30% of the floatation value. This conclusion is reinforced by direct measurements of water pressure beneath portions of the West Antarctic ice sheet, which indicate average headsbed, despite thick ice at subfreezing temperatures. Therefore, in models of subglacial groundwater flow used to assess sites for nuclear waste repositories, a flux upper boundary condition based on water input from only basal melting will be far more uncertain than applying a hydraulic head at the upper boundary set equal to a large fraction of the floatation value. Text Antarc* Antarctic Ice Sheet Digital Repository @ Iowa State University Antarctic West Antarctic Ice Sheet |
institution |
Open Polar |
collection |
Digital Repository @ Iowa State University |
op_collection_id |
ftiowastateuniv |
language |
English |
topic |
erosion geomorphic glacial hydrogeology hydrology ice tectonics Geomorphology Glaciology Sedimentology Tectonics and Structure |
spellingShingle |
erosion geomorphic glacial hydrogeology hydrology ice tectonics Geomorphology Glaciology Sedimentology Tectonics and Structure Iverson, Neal R. Person, Mark Glacier-bed geomorphic processes and hydrologic conditions relevant to nuclear waste disposal |
topic_facet |
erosion geomorphic glacial hydrogeology hydrology ice tectonics Geomorphology Glaciology Sedimentology Tectonics and Structure |
description |
Characterizing glaciotectonic deformation, glacial erosion and sedimentation, and basal hydrologic conditions of ice sheets is vital for selecting sites for nuclear waste repositories at high latitudes. Glaciotectonic deformation is enhanced by excess pore pressures that commonly persist near ice sheet margins. Depths of such deformation can extend locally to a few tens of meters, with depths up to approximately 300 m in exceptional cases. Rates of glacial erosion are highly variable (0.05–15 mm a−1), but ratesa−1 are expected in tectonically quiescent regions. Total erosion probably not exceeding several tens of meters is expected during a glacial cycle, although locally erosion could be greater. Consolidation of glacial sediments that is less than expected from independent estimates of glacier thickness indicates that heads at the bases of past ice sheets were usually within 30% of the floatation value. This conclusion is reinforced by direct measurements of water pressure beneath portions of the West Antarctic ice sheet, which indicate average headsbed, despite thick ice at subfreezing temperatures. Therefore, in models of subglacial groundwater flow used to assess sites for nuclear waste repositories, a flux upper boundary condition based on water input from only basal melting will be far more uncertain than applying a hydraulic head at the upper boundary set equal to a large fraction of the floatation value. |
format |
Text |
author |
Iverson, Neal R. Person, Mark |
author_facet |
Iverson, Neal R. Person, Mark |
author_sort |
Iverson, Neal R. |
title |
Glacier-bed geomorphic processes and hydrologic conditions relevant to nuclear waste disposal |
title_short |
Glacier-bed geomorphic processes and hydrologic conditions relevant to nuclear waste disposal |
title_full |
Glacier-bed geomorphic processes and hydrologic conditions relevant to nuclear waste disposal |
title_fullStr |
Glacier-bed geomorphic processes and hydrologic conditions relevant to nuclear waste disposal |
title_full_unstemmed |
Glacier-bed geomorphic processes and hydrologic conditions relevant to nuclear waste disposal |
title_sort |
glacier-bed geomorphic processes and hydrologic conditions relevant to nuclear waste disposal |
publisher |
Iowa State University Digital Repository |
publishDate |
2012 |
url |
https://lib.dr.iastate.edu/ge_at_pubs/149 https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1138&context=ge_at_pubs |
geographic |
Antarctic West Antarctic Ice Sheet |
geographic_facet |
Antarctic West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Ice Sheet |
genre_facet |
Antarc* Antarctic Ice Sheet |
op_source |
Geological and Atmospheric Sciences Publications |
op_relation |
https://lib.dr.iastate.edu/ge_at_pubs/149 https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1138&context=ge_at_pubs |
op_rights |
Creative Commons Attribution license |
op_rightsnorm |
CC-BY |
_version_ |
1766074940863283200 |