Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica
A dense grid of ice-penetrating radar sections acquired over Pine Island Glacier, West Antarctica has revealed a network of sinuous subglacial channels, typically 500m to 3km wide, and up to 200m high, in the ice-shelf base. These subglacial channels develop while the ice is floating and result from...
Published in: | Journal of Geophysical Research: Earth Surface |
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American Geophysical Union
2012
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ftunivnorthumb:oai:nrl.northumbria.ac.uk:37393 2023-05-15T13:56:54+02:00 Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica Vaughan, David Corr, Hugh Bindschadler, Robert Dutrieux, Pierre Gudmundsson, Hilmar Jenkins, Adrian Newman, Thomas Vornberger, Patricia Wingham, Duncan 2012-09 https://nrl.northumbria.ac.uk/id/eprint/37393/ https://doi.org/10.1029/2012JF002360 unknown American Geophysical Union Vaughan, David, Corr, Hugh, Bindschadler, Robert, Dutrieux, Pierre, Gudmundsson, Hilmar, Jenkins, Adrian, Newman, Thomas, Vornberger, Patricia and Wingham, Duncan (2012) Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica. Journal of Geophysical Research, 117 (F3). ISSN 0148-0227 F800 Physical and Terrestrial Geographical and Environmental Sciences Article PeerReviewed 2012 ftunivnorthumb https://doi.org/10.1029/2012JF002360 2022-09-25T06:08:52Z A dense grid of ice-penetrating radar sections acquired over Pine Island Glacier, West Antarctica has revealed a network of sinuous subglacial channels, typically 500m to 3km wide, and up to 200m high, in the ice-shelf base. These subglacial channels develop while the ice is floating and result from melting at the base of the ice shelf. Above the apex of most channels, the radar shows isolated reflections from within the ice shelf. Comparison of the radar data with acoustic data obtained using an autonomous submersible, confirms that these echoes arise from open basal crevasses 50-100m wide aligned with the subglacial channels and penetrating up to 1/3 of the ice thickness. Analogous sets of surface crevasses appear on the ridges between the basal channels. We suggest that both sets of crevasses were formed during the melting of the subglacial channels as a response to vertical flexing of the ice shelf toward the hydrostatic condition. Finite element modeling of stresses produced after the formation of idealized basal channels indicates that the stresses generated have the correct pattern and, if the channels were formed sufficiently rapidly, would have sufficient magnitude to explain the formation of the observed basal and surface crevasse sets. We conclude that ice-shelf basal melting plays a role in determining patterns of surface and basal crevassing. Increased delivery of warm ocean water into the sub-ice shelf cavity may therefore cause not only thinning but also structural weakening of the ice shelf, perhaps, as a prelude to eventual collapse. Article in Journal/Newspaper Antarc* Antarctica Antarctica Journal Ice Shelf Pine Island Pine Island Glacier West Antarctica Northumbria University, Newcastle: Northumbria Research Link (NRL) Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) West Antarctica Journal of Geophysical Research: Earth Surface 117 F3 n/a n/a |
institution |
Open Polar |
collection |
Northumbria University, Newcastle: Northumbria Research Link (NRL) |
op_collection_id |
ftunivnorthumb |
language |
unknown |
topic |
F800 Physical and Terrestrial Geographical and Environmental Sciences |
spellingShingle |
F800 Physical and Terrestrial Geographical and Environmental Sciences Vaughan, David Corr, Hugh Bindschadler, Robert Dutrieux, Pierre Gudmundsson, Hilmar Jenkins, Adrian Newman, Thomas Vornberger, Patricia Wingham, Duncan Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica |
topic_facet |
F800 Physical and Terrestrial Geographical and Environmental Sciences |
description |
A dense grid of ice-penetrating radar sections acquired over Pine Island Glacier, West Antarctica has revealed a network of sinuous subglacial channels, typically 500m to 3km wide, and up to 200m high, in the ice-shelf base. These subglacial channels develop while the ice is floating and result from melting at the base of the ice shelf. Above the apex of most channels, the radar shows isolated reflections from within the ice shelf. Comparison of the radar data with acoustic data obtained using an autonomous submersible, confirms that these echoes arise from open basal crevasses 50-100m wide aligned with the subglacial channels and penetrating up to 1/3 of the ice thickness. Analogous sets of surface crevasses appear on the ridges between the basal channels. We suggest that both sets of crevasses were formed during the melting of the subglacial channels as a response to vertical flexing of the ice shelf toward the hydrostatic condition. Finite element modeling of stresses produced after the formation of idealized basal channels indicates that the stresses generated have the correct pattern and, if the channels were formed sufficiently rapidly, would have sufficient magnitude to explain the formation of the observed basal and surface crevasse sets. We conclude that ice-shelf basal melting plays a role in determining patterns of surface and basal crevassing. Increased delivery of warm ocean water into the sub-ice shelf cavity may therefore cause not only thinning but also structural weakening of the ice shelf, perhaps, as a prelude to eventual collapse. |
format |
Article in Journal/Newspaper |
author |
Vaughan, David Corr, Hugh Bindschadler, Robert Dutrieux, Pierre Gudmundsson, Hilmar Jenkins, Adrian Newman, Thomas Vornberger, Patricia Wingham, Duncan |
author_facet |
Vaughan, David Corr, Hugh Bindschadler, Robert Dutrieux, Pierre Gudmundsson, Hilmar Jenkins, Adrian Newman, Thomas Vornberger, Patricia Wingham, Duncan |
author_sort |
Vaughan, David |
title |
Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica |
title_short |
Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica |
title_full |
Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica |
title_fullStr |
Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica |
title_full_unstemmed |
Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica |
title_sort |
subglacial melt channels and fracture in the floating part of pine island glacier, antarctica |
publisher |
American Geophysical Union |
publishDate |
2012 |
url |
https://nrl.northumbria.ac.uk/id/eprint/37393/ https://doi.org/10.1029/2012JF002360 |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) |
geographic |
Pine Island Glacier West Antarctica |
geographic_facet |
Pine Island Glacier West Antarctica |
genre |
Antarc* Antarctica Antarctica Journal Ice Shelf Pine Island Pine Island Glacier West Antarctica |
genre_facet |
Antarc* Antarctica Antarctica Journal Ice Shelf Pine Island Pine Island Glacier West Antarctica |
op_relation |
Vaughan, David, Corr, Hugh, Bindschadler, Robert, Dutrieux, Pierre, Gudmundsson, Hilmar, Jenkins, Adrian, Newman, Thomas, Vornberger, Patricia and Wingham, Duncan (2012) Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica. Journal of Geophysical Research, 117 (F3). ISSN 0148-0227 |
op_doi |
https://doi.org/10.1029/2012JF002360 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
117 |
container_issue |
F3 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1766264501524496384 |