The effects of sedimentary basins on the dynamics of the East Antarctic Ice Sheet from enhanced groundwater and geothermal heat flow

It is well known that ice sheets heavily influence groundwater systems, however, the impact of groundwater on ice sheet dynamics is not. This poorly understood aspect of ice-sheet hydrology is relevant to the subglacial hydrology of ice sheets lacking surface or englacial meltwater such as the East...

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Main Author: Gooch, Bradley Tyler
Other Authors: Blankenship, Donald D., Dalziel, Ian W, Ghattas, Omar, Hesse, Marc A, Young, Duncan A
Format: Thesis
Language:English
Published: 2016
Subjects:
Online Access:http://hdl.handle.net/2152/45934
https://doi.org/10.15781/T2W08WN1X
id ftunivtexas:oai:repositories.lib.utexas.edu:2152/45934
record_format openpolar
spelling ftunivtexas:oai:repositories.lib.utexas.edu:2152/45934 2023-05-15T14:01:43+02:00 The effects of sedimentary basins on the dynamics of the East Antarctic Ice Sheet from enhanced groundwater and geothermal heat flow Gooch, Bradley Tyler Blankenship, Donald D. Dalziel, Ian W Ghattas, Omar Hesse, Marc A Young, Duncan A 2016-05 application/pdf http://hdl.handle.net/2152/45934 https://doi.org/10.15781/T2W08WN1X en eng doi:10.15781/T2W08WN1X http://hdl.handle.net/2152/45934 Antarctica Groundwater Hydrogeology Cryosphere COMSOL East Antarctic Ice Sheet Basin-scale groundwater flow Geothermal heat Ice sheet hydrology Mathematical models Thesis text 2016 ftunivtexas https://doi.org/10.15781/T2W08WN1X 2020-12-23T22:10:23Z It is well known that ice sheets heavily influence groundwater systems, however, the impact of groundwater on ice sheet dynamics is not. This poorly understood aspect of ice-sheet hydrology is relevant to the subglacial hydrology of ice sheets lacking surface or englacial meltwater such as the East Antarctic Ice Sheet (EAIS). How groundwater systems redistribute geothermal heat at the base of an ice sheet is also largely unknown. Geothermal heat and subglacial hydrology are important basal processes controlling ice flow. Large sedimentary basins underlie the EAIS, which likely play host to many groundwater systems. I hypothesized that groundwater systems in these sedimentary basins may be the main water transport mechanism over water sheets (or films) at large scales in the interior of the ice sheet where basal melt rates are very low. I also hypothesized that these groundwater systems are likely important to the basal processes (specifically heat flux) and dynamics of the EAIS (particularly in rheological and sliding behavior). To test these, I created various one- and two-dimensional numerical models incorporating relevant datasets and conservative assumptions about the subsurface. The models ranged from simple groundwater and thermal simulations to a complex subsurface fluid and thermal model coupled to a fully dynamic ice sheet simulator. The models suggest that groundwater most likely has measurable effects on the dynamics of ice sheets like the EAIS. I have shown that probable groundwater systems underneath the interior of the EAIS can likely transport most of the meltwater produced and that groundwater can strongly affect the heat flux (positively, as well as, negatively) at the ice base under kilometers of relatively slow-moving ice. I have also not only shown that groundwater systems under the EAIS are strongly controlled by the ice sheet’s dynamics but that groundwater systems have a feedback to the ice dynamics, mostly through enhanced basal sliding and changes to the ice rheology. These results provide the justification to include groundwater in future simulations of the EAIS as well as a call to collect more data to better delineate its subsurface sedimentary basins – a critical input for groundwater and heat transport modeling. Geological Sciences Thesis Antarc* Antarctic Antarctica Ice Sheet The University of Texas at Austin: Texas ScholarWorks Antarctic East Antarctic Ice Sheet
institution Open Polar
collection The University of Texas at Austin: Texas ScholarWorks
op_collection_id ftunivtexas
language English
topic Antarctica
Groundwater
Hydrogeology
Cryosphere
COMSOL
East Antarctic Ice Sheet
Basin-scale groundwater flow
Geothermal heat
Ice sheet hydrology
Mathematical models
spellingShingle Antarctica
Groundwater
Hydrogeology
Cryosphere
COMSOL
East Antarctic Ice Sheet
Basin-scale groundwater flow
Geothermal heat
Ice sheet hydrology
Mathematical models
Gooch, Bradley Tyler
The effects of sedimentary basins on the dynamics of the East Antarctic Ice Sheet from enhanced groundwater and geothermal heat flow
topic_facet Antarctica
Groundwater
Hydrogeology
Cryosphere
COMSOL
East Antarctic Ice Sheet
Basin-scale groundwater flow
Geothermal heat
Ice sheet hydrology
Mathematical models
description It is well known that ice sheets heavily influence groundwater systems, however, the impact of groundwater on ice sheet dynamics is not. This poorly understood aspect of ice-sheet hydrology is relevant to the subglacial hydrology of ice sheets lacking surface or englacial meltwater such as the East Antarctic Ice Sheet (EAIS). How groundwater systems redistribute geothermal heat at the base of an ice sheet is also largely unknown. Geothermal heat and subglacial hydrology are important basal processes controlling ice flow. Large sedimentary basins underlie the EAIS, which likely play host to many groundwater systems. I hypothesized that groundwater systems in these sedimentary basins may be the main water transport mechanism over water sheets (or films) at large scales in the interior of the ice sheet where basal melt rates are very low. I also hypothesized that these groundwater systems are likely important to the basal processes (specifically heat flux) and dynamics of the EAIS (particularly in rheological and sliding behavior). To test these, I created various one- and two-dimensional numerical models incorporating relevant datasets and conservative assumptions about the subsurface. The models ranged from simple groundwater and thermal simulations to a complex subsurface fluid and thermal model coupled to a fully dynamic ice sheet simulator. The models suggest that groundwater most likely has measurable effects on the dynamics of ice sheets like the EAIS. I have shown that probable groundwater systems underneath the interior of the EAIS can likely transport most of the meltwater produced and that groundwater can strongly affect the heat flux (positively, as well as, negatively) at the ice base under kilometers of relatively slow-moving ice. I have also not only shown that groundwater systems under the EAIS are strongly controlled by the ice sheet’s dynamics but that groundwater systems have a feedback to the ice dynamics, mostly through enhanced basal sliding and changes to the ice rheology. These results provide the justification to include groundwater in future simulations of the EAIS as well as a call to collect more data to better delineate its subsurface sedimentary basins – a critical input for groundwater and heat transport modeling. Geological Sciences
author2 Blankenship, Donald D.
Dalziel, Ian W
Ghattas, Omar
Hesse, Marc A
Young, Duncan A
format Thesis
author Gooch, Bradley Tyler
author_facet Gooch, Bradley Tyler
author_sort Gooch, Bradley Tyler
title The effects of sedimentary basins on the dynamics of the East Antarctic Ice Sheet from enhanced groundwater and geothermal heat flow
title_short The effects of sedimentary basins on the dynamics of the East Antarctic Ice Sheet from enhanced groundwater and geothermal heat flow
title_full The effects of sedimentary basins on the dynamics of the East Antarctic Ice Sheet from enhanced groundwater and geothermal heat flow
title_fullStr The effects of sedimentary basins on the dynamics of the East Antarctic Ice Sheet from enhanced groundwater and geothermal heat flow
title_full_unstemmed The effects of sedimentary basins on the dynamics of the East Antarctic Ice Sheet from enhanced groundwater and geothermal heat flow
title_sort effects of sedimentary basins on the dynamics of the east antarctic ice sheet from enhanced groundwater and geothermal heat flow
publishDate 2016
url http://hdl.handle.net/2152/45934
https://doi.org/10.15781/T2W08WN1X
geographic Antarctic
East Antarctic Ice Sheet
geographic_facet Antarctic
East Antarctic Ice Sheet
genre Antarc*
Antarctic
Antarctica
Ice Sheet
genre_facet Antarc*
Antarctic
Antarctica
Ice Sheet
op_relation doi:10.15781/T2W08WN1X
http://hdl.handle.net/2152/45934
op_doi https://doi.org/10.15781/T2W08WN1X
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