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 500 m to 3 km wide, and up to 200 m high, in the ice-shelf base. These subglacial channels develop while the ice is floating and result f...
Published in: | Journal of Geophysical Research: Earth Surface |
---|---|
Main Authors: | , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Geophysical Union
2012
|
Subjects: | |
Online Access: | http://nora.nerc.ac.uk/id/eprint/19568/ https://nora.nerc.ac.uk/id/eprint/19568/1/2012JF002360.pdf https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2012JF002360 |
id |
ftnerc:oai:nora.nerc.ac.uk:19568 |
---|---|
record_format |
openpolar |
spelling |
ftnerc:oai:nora.nerc.ac.uk:19568 2023-05-15T13:45:12+02:00 Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica Vaughan, David G. Corr, Hugh F. J. Bindschadler, Robert A. Dutrieux, Pierre Gudmundsson, G. Hilmar Jenkins, Adrian Newman, Thomas Vornberger, Patricia Wingham, Duncan J. 2012-09 text http://nora.nerc.ac.uk/id/eprint/19568/ https://nora.nerc.ac.uk/id/eprint/19568/1/2012JF002360.pdf https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2012JF002360 en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/19568/1/2012JF002360.pdf Vaughan, David G. orcid:0000-0002-9065-0570 Corr, Hugh F. J.; Bindschadler, Robert A.; Dutrieux, Pierre orcid:0000-0002-8066-934X Gudmundsson, G. Hilmar orcid:0000-0003-4236-5369 Jenkins, Adrian orcid:0000-0002-9117-0616 Newman, Thomas; Vornberger, Patricia; Wingham, Duncan J. 2012 Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica. Journal of Geophysical Research, 117 (F3), F03012. 10, pp. https://doi.org/10.1029/2012JF002360 <https://doi.org/10.1029/2012JF002360> Glaciology Publication - Article PeerReviewed 2012 ftnerc https://doi.org/10.1029/2012JF002360 2023-02-04T19:32:22Z A dense grid of ice-penetrating radar sections acquired over Pine Island Glacier, West Antarctica has revealed a network of sinuous subglacial channels, typically 500 m to 3 km wide, and up to 200 m 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 50–100 m 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 Natural Environment Research Council: NERC Open Research Archive West Antarctica Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) Journal of Geophysical Research: Earth Surface 117 F3 n/a n/a |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
topic |
Glaciology |
spellingShingle |
Glaciology Vaughan, David G. Corr, Hugh F. J. Bindschadler, Robert A. Dutrieux, Pierre Gudmundsson, G. Hilmar Jenkins, Adrian Newman, Thomas Vornberger, Patricia Wingham, Duncan J. Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica |
topic_facet |
Glaciology |
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 500 m to 3 km wide, and up to 200 m 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 50–100 m 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 G. Corr, Hugh F. J. Bindschadler, Robert A. Dutrieux, Pierre Gudmundsson, G. Hilmar Jenkins, Adrian Newman, Thomas Vornberger, Patricia Wingham, Duncan J. |
author_facet |
Vaughan, David G. Corr, Hugh F. J. Bindschadler, Robert A. Dutrieux, Pierre Gudmundsson, G. Hilmar Jenkins, Adrian Newman, Thomas Vornberger, Patricia Wingham, Duncan J. |
author_sort |
Vaughan, David G. |
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 |
http://nora.nerc.ac.uk/id/eprint/19568/ https://nora.nerc.ac.uk/id/eprint/19568/1/2012JF002360.pdf https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2012JF002360 |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) |
geographic |
West Antarctica Pine Island Glacier |
geographic_facet |
West Antarctica Pine Island Glacier |
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 |
https://nora.nerc.ac.uk/id/eprint/19568/1/2012JF002360.pdf Vaughan, David G. orcid:0000-0002-9065-0570 Corr, Hugh F. J.; Bindschadler, Robert A.; Dutrieux, Pierre orcid:0000-0002-8066-934X Gudmundsson, G. Hilmar orcid:0000-0003-4236-5369 Jenkins, Adrian orcid:0000-0002-9117-0616 Newman, Thomas; Vornberger, Patricia; Wingham, Duncan J. 2012 Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica. Journal of Geophysical Research, 117 (F3), F03012. 10, pp. https://doi.org/10.1029/2012JF002360 <https://doi.org/10.1029/2012JF002360> |
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_ |
1766216844928090112 |