Seismic evidence for complex sedimentary control of Greenland Ice Sheet flow
Source at: http://doi.org/10.1126/sciadv.1603071 The land-terminating margin of the Greenland Ice Sheet has slowed down in recent decades, although the causes and implications for future ice flow are unclear. Explained originally by a self-regulating mechanism where basal slip reduces as drainage ev...
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Online Access: | https://hdl.handle.net/10037/12459 https://doi.org/10.1126/sciadv.1603071 |
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ftunivtroemsoe:oai:munin.uit.no:10037/12459 2023-05-15T14:27:18+02:00 Seismic evidence for complex sedimentary control of Greenland Ice Sheet flow Kulessa, Bernd Hubbard, Alun Lloyd Booth, Adam D. Bougamont, Marion Dow, Christine F. Doyle, Samuel H. Christoffersen, Poul Lindbäck, Katrin Pettersson, Rickard Fitzpatrick, Andrew A.W. Jones, Glenn A. 2017-08-16 https://hdl.handle.net/10037/12459 https://doi.org/10.1126/sciadv.1603071 eng eng American Association for the Advancement of Science: Science Advances Science Advances info:eu-repo/grantAgreement/RCN/SFF/223259/Norway/Centre for Arctic Gas Hydrate, Environment and Climate/CAGE/ Kulessa, B., Hubbard, A. L., Booth, A. D., Bougamont, M., Dow, C. F., Doyle, S. H., Christoffersen, P., . Jones, G. A. (2017). Seismic evidence for complex sedimentary control of Greenland Ice Sheet flow. Science Advances, 3(8), 1-9. http://doi.org/10.1126/sciadv.1603071 FRIDAID 1487549 doi:10.1126/sciadv.1603071 2375-2548 https://hdl.handle.net/10037/12459 openAccess VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Kvartærgeologi glasiologi: 465 VDP::Mathematics and natural science: 400::Geosciences: 450::Quaternary geology glaciology: 465 Journal article Tidsskriftartikkel Peer reviewed 2017 ftunivtroemsoe https://doi.org/10.1126/sciadv.1603071 2021-06-25T17:55:39Z Source at: http://doi.org/10.1126/sciadv.1603071 The land-terminating margin of the Greenland Ice Sheet has slowed down in recent decades, although the causes and implications for future ice flow are unclear. Explained originally by a self-regulating mechanism where basal slip reduces as drainage evolves from low to high efficiency, recent numerical modeling invokes a sedimentary control of ice sheet flow as an alternative hypothesis. Although both hypotheses can explain the recent slowdown, their respective forecasts of a long-term deceleration versus an acceleration of ice flow are contradictory. We present amplitude-versus-angle seismic data as the first observational test of the alternative hypothesis. We document transient modifications of basal sediment strengths by rapid subglacial drainages of supraglacial lakes, the primary current control on summer ice sheet flow according to our numerical model. Our observations agree with simulations of initial postdrainage sediment weakening and ice flow accelerations, and subsequent sediment restrengthening and ice flow decelerations, and thus confirm the alternative hypothesis. Although simulated melt season acceleration of ice flow due to weakening of subglacial sediments does not currently outweigh winter slowdown forced by selfregulation, they could dominate over the longer term. Subglacial sediments beneath the Greenland Ice Sheet must therefore be mapped and characterized, and a sedimentary control of ice flow must be evaluated against competing self-regulation mechanisms. Article in Journal/Newspaper Arctic Greenland Ice Sheet University of Tromsø: Munin Open Research Archive Greenland Science Advances 3 8 e1603071 |
institution |
Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Kvartærgeologi glasiologi: 465 VDP::Mathematics and natural science: 400::Geosciences: 450::Quaternary geology glaciology: 465 |
spellingShingle |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Kvartærgeologi glasiologi: 465 VDP::Mathematics and natural science: 400::Geosciences: 450::Quaternary geology glaciology: 465 Kulessa, Bernd Hubbard, Alun Lloyd Booth, Adam D. Bougamont, Marion Dow, Christine F. Doyle, Samuel H. Christoffersen, Poul Lindbäck, Katrin Pettersson, Rickard Fitzpatrick, Andrew A.W. Jones, Glenn A. Seismic evidence for complex sedimentary control of Greenland Ice Sheet flow |
topic_facet |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Kvartærgeologi glasiologi: 465 VDP::Mathematics and natural science: 400::Geosciences: 450::Quaternary geology glaciology: 465 |
description |
Source at: http://doi.org/10.1126/sciadv.1603071 The land-terminating margin of the Greenland Ice Sheet has slowed down in recent decades, although the causes and implications for future ice flow are unclear. Explained originally by a self-regulating mechanism where basal slip reduces as drainage evolves from low to high efficiency, recent numerical modeling invokes a sedimentary control of ice sheet flow as an alternative hypothesis. Although both hypotheses can explain the recent slowdown, their respective forecasts of a long-term deceleration versus an acceleration of ice flow are contradictory. We present amplitude-versus-angle seismic data as the first observational test of the alternative hypothesis. We document transient modifications of basal sediment strengths by rapid subglacial drainages of supraglacial lakes, the primary current control on summer ice sheet flow according to our numerical model. Our observations agree with simulations of initial postdrainage sediment weakening and ice flow accelerations, and subsequent sediment restrengthening and ice flow decelerations, and thus confirm the alternative hypothesis. Although simulated melt season acceleration of ice flow due to weakening of subglacial sediments does not currently outweigh winter slowdown forced by selfregulation, they could dominate over the longer term. Subglacial sediments beneath the Greenland Ice Sheet must therefore be mapped and characterized, and a sedimentary control of ice flow must be evaluated against competing self-regulation mechanisms. |
format |
Article in Journal/Newspaper |
author |
Kulessa, Bernd Hubbard, Alun Lloyd Booth, Adam D. Bougamont, Marion Dow, Christine F. Doyle, Samuel H. Christoffersen, Poul Lindbäck, Katrin Pettersson, Rickard Fitzpatrick, Andrew A.W. Jones, Glenn A. |
author_facet |
Kulessa, Bernd Hubbard, Alun Lloyd Booth, Adam D. Bougamont, Marion Dow, Christine F. Doyle, Samuel H. Christoffersen, Poul Lindbäck, Katrin Pettersson, Rickard Fitzpatrick, Andrew A.W. Jones, Glenn A. |
author_sort |
Kulessa, Bernd |
title |
Seismic evidence for complex sedimentary control of Greenland Ice Sheet flow |
title_short |
Seismic evidence for complex sedimentary control of Greenland Ice Sheet flow |
title_full |
Seismic evidence for complex sedimentary control of Greenland Ice Sheet flow |
title_fullStr |
Seismic evidence for complex sedimentary control of Greenland Ice Sheet flow |
title_full_unstemmed |
Seismic evidence for complex sedimentary control of Greenland Ice Sheet flow |
title_sort |
seismic evidence for complex sedimentary control of greenland ice sheet flow |
publisher |
American Association for the Advancement of Science: Science Advances |
publishDate |
2017 |
url |
https://hdl.handle.net/10037/12459 https://doi.org/10.1126/sciadv.1603071 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Arctic Greenland Ice Sheet |
genre_facet |
Arctic Greenland Ice Sheet |
op_relation |
Science Advances info:eu-repo/grantAgreement/RCN/SFF/223259/Norway/Centre for Arctic Gas Hydrate, Environment and Climate/CAGE/ Kulessa, B., Hubbard, A. L., Booth, A. D., Bougamont, M., Dow, C. F., Doyle, S. H., Christoffersen, P., . Jones, G. A. (2017). Seismic evidence for complex sedimentary control of Greenland Ice Sheet flow. Science Advances, 3(8), 1-9. http://doi.org/10.1126/sciadv.1603071 FRIDAID 1487549 doi:10.1126/sciadv.1603071 2375-2548 https://hdl.handle.net/10037/12459 |
op_rights |
openAccess |
op_doi |
https://doi.org/10.1126/sciadv.1603071 |
container_title |
Science Advances |
container_volume |
3 |
container_issue |
8 |
container_start_page |
e1603071 |
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1766300987970027520 |