Subglacial hydrology indicates a major shift in dynamics of the West Antarctic Ross Ice Streams within the next two centuries
The mass export of the West Antarctic Ice Sheet (WAIS) is dominated by fast flowing ice streams. Understanding their dynamics is a key to estimate the future integrity of the WAIS and its contributions to global sea level rise. This study focuses on the Ross Ice Streams (RIS) at the Siple Coast. In...
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ftcopernicus:oai:publications.copernicus.org:tcd30933 2023-05-15T13:54:27+02:00 Subglacial hydrology indicates a major shift in dynamics of the West Antarctic Ross Ice Streams within the next two centuries Goeller, S. Helm, V. Thoma, M. Grosfeld, K. 2018-09-26 application/pdf https://doi.org/10.5194/tcd-9-3995-2015 https://tc.copernicus.org/preprints/tc-2015-106/ eng eng doi:10.5194/tcd-9-3995-2015 https://tc.copernicus.org/preprints/tc-2015-106/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tcd-9-3995-2015 2020-07-20T16:24:30Z The mass export of the West Antarctic Ice Sheet (WAIS) is dominated by fast flowing ice streams. Understanding their dynamics is a key to estimate the future integrity of the WAIS and its contributions to global sea level rise. This study focuses on the Ross Ice Streams (RIS) at the Siple Coast. In this sector, observations reveal a high variability of ice stream pathways and velocities which is assumed to be driven by subglacial hydrology. We compute subglacial water pathways for the present-day ice sheet and verify this assumption by finding high correlations between areas of enhanced basal water flow and the locations of the RIS. Moreover, we reveal that the ice flow velocities of the individual ice streams are correlated with the sizes of the water catchment areas draining underneath. The future development of the subglacial hydraulic environment is estimated by applying ice surface elevation change rates observed by ICESat and CryoSat-2 to the present-day ice sheet geometry and thus assessing prognostic basal pressure conditions. Our simulations consistently indicate that a major hydraulic tributary of the Kamb and Whillans Ice Stream (KIS and WIS) will be redirected underneath the Bindschadler Ice Stream (BIS) within the next two centuries. The water catchment area feeding underneath the BIS is estimated to grow by about 50 % while the lower part of the stagnated KIS becomes increasingly separated from its upper hydraulic tributaries. We conclude, that this might be a continuation of the subglacial hydraulic processes which caused the past stagnation of the KIS. The simulated hydraulic rerouting is also capable to explain the observed deceleration of the WIS and indicates a possible future acceleration of the BIS accompanied by an increased ice drainage of the corresponding ice sheet interior. Text Antarc* Antarctic Bindschadler Ice Stream Ice Sheet Whillans Ice Stream Copernicus Publications: E-Journals Antarctic Bindschadler Ice Stream ENVELOPE(-142.000,-142.000,-81.000,-81.000) Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Siple Coast ENVELOPE(-155.000,-155.000,-82.000,-82.000) West Antarctic Ice Sheet Whillans ENVELOPE(-64.250,-64.250,-84.450,-84.450) Whillans Ice Stream ENVELOPE(-145.000,-145.000,-83.667,-83.667) |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
The mass export of the West Antarctic Ice Sheet (WAIS) is dominated by fast flowing ice streams. Understanding their dynamics is a key to estimate the future integrity of the WAIS and its contributions to global sea level rise. This study focuses on the Ross Ice Streams (RIS) at the Siple Coast. In this sector, observations reveal a high variability of ice stream pathways and velocities which is assumed to be driven by subglacial hydrology. We compute subglacial water pathways for the present-day ice sheet and verify this assumption by finding high correlations between areas of enhanced basal water flow and the locations of the RIS. Moreover, we reveal that the ice flow velocities of the individual ice streams are correlated with the sizes of the water catchment areas draining underneath. The future development of the subglacial hydraulic environment is estimated by applying ice surface elevation change rates observed by ICESat and CryoSat-2 to the present-day ice sheet geometry and thus assessing prognostic basal pressure conditions. Our simulations consistently indicate that a major hydraulic tributary of the Kamb and Whillans Ice Stream (KIS and WIS) will be redirected underneath the Bindschadler Ice Stream (BIS) within the next two centuries. The water catchment area feeding underneath the BIS is estimated to grow by about 50 % while the lower part of the stagnated KIS becomes increasingly separated from its upper hydraulic tributaries. We conclude, that this might be a continuation of the subglacial hydraulic processes which caused the past stagnation of the KIS. The simulated hydraulic rerouting is also capable to explain the observed deceleration of the WIS and indicates a possible future acceleration of the BIS accompanied by an increased ice drainage of the corresponding ice sheet interior. |
format |
Text |
author |
Goeller, S. Helm, V. Thoma, M. Grosfeld, K. |
spellingShingle |
Goeller, S. Helm, V. Thoma, M. Grosfeld, K. Subglacial hydrology indicates a major shift in dynamics of the West Antarctic Ross Ice Streams within the next two centuries |
author_facet |
Goeller, S. Helm, V. Thoma, M. Grosfeld, K. |
author_sort |
Goeller, S. |
title |
Subglacial hydrology indicates a major shift in dynamics of the West Antarctic Ross Ice Streams within the next two centuries |
title_short |
Subglacial hydrology indicates a major shift in dynamics of the West Antarctic Ross Ice Streams within the next two centuries |
title_full |
Subglacial hydrology indicates a major shift in dynamics of the West Antarctic Ross Ice Streams within the next two centuries |
title_fullStr |
Subglacial hydrology indicates a major shift in dynamics of the West Antarctic Ross Ice Streams within the next two centuries |
title_full_unstemmed |
Subglacial hydrology indicates a major shift in dynamics of the West Antarctic Ross Ice Streams within the next two centuries |
title_sort |
subglacial hydrology indicates a major shift in dynamics of the west antarctic ross ice streams within the next two centuries |
publishDate |
2018 |
url |
https://doi.org/10.5194/tcd-9-3995-2015 https://tc.copernicus.org/preprints/tc-2015-106/ |
long_lat |
ENVELOPE(-142.000,-142.000,-81.000,-81.000) ENVELOPE(-83.917,-83.917,-75.917,-75.917) ENVELOPE(-155.000,-155.000,-82.000,-82.000) ENVELOPE(-64.250,-64.250,-84.450,-84.450) ENVELOPE(-145.000,-145.000,-83.667,-83.667) |
geographic |
Antarctic Bindschadler Ice Stream Siple Siple Coast West Antarctic Ice Sheet Whillans Whillans Ice Stream |
geographic_facet |
Antarctic Bindschadler Ice Stream Siple Siple Coast West Antarctic Ice Sheet Whillans Whillans Ice Stream |
genre |
Antarc* Antarctic Bindschadler Ice Stream Ice Sheet Whillans Ice Stream |
genre_facet |
Antarc* Antarctic Bindschadler Ice Stream Ice Sheet Whillans Ice Stream |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tcd-9-3995-2015 https://tc.copernicus.org/preprints/tc-2015-106/ |
op_doi |
https://doi.org/10.5194/tcd-9-3995-2015 |
_version_ |
1766260350650417152 |