Sea-bed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier
Ice shelves are critical features in the debate about West Antarctic ice sheet change and sea level rise, both because they limit ice discharge and because they are sensitive to change in the surrounding ocean. The Pine Island Glacier ice shelf has been thinning rapidly since at least the early 1990...
Published in: | Journal of Geophysical Research: Earth Surface |
---|---|
Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Geophysical Union
2013
|
Subjects: | |
Online Access: | http://nora.nerc.ac.uk/id/eprint/502340/ https://nora.nerc.ac.uk/id/eprint/502340/1/jgrf20087.pdf https://doi.org/10.1002/jgrf.20087 |
id |
ftnerc:oai:nora.nerc.ac.uk:502340 |
---|---|
record_format |
openpolar |
spelling |
ftnerc:oai:nora.nerc.ac.uk:502340 2023-05-15T13:48:07+02:00 Sea-bed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier Graham, Alastair G. C. Dutrieux, Pierre Vaughan, David G. Nitsche, Frank O. Gyllencreutz, Richard Greenwood, Sarah L. Larter, Robert D. Jenkins, Adrian 2013-09 text http://nora.nerc.ac.uk/id/eprint/502340/ https://nora.nerc.ac.uk/id/eprint/502340/1/jgrf20087.pdf https://doi.org/10.1002/jgrf.20087 en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/502340/1/jgrf20087.pdf Graham, Alastair G. C.; Dutrieux, Pierre orcid:0000-0002-8066-934X Vaughan, David G. orcid:0000-0002-9065-0570 Nitsche, Frank O.; Gyllencreutz, Richard; Greenwood, Sarah L.; Larter, Robert D. orcid:0000-0002-8414-7389 Jenkins, Adrian orcid:0000-0002-9117-0616 . 2013 Sea-bed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier. Journal of Geophysical Research: Earth Surface, 118 (3). 1356-1366. https://doi.org/10.1002/jgrf.20087 <https://doi.org/10.1002/jgrf.20087> Glaciology Publication - Article PeerReviewed 2013 ftnerc https://doi.org/10.1002/jgrf.20087 2023-02-04T19:37:13Z Ice shelves are critical features in the debate about West Antarctic ice sheet change and sea level rise, both because they limit ice discharge and because they are sensitive to change in the surrounding ocean. The Pine Island Glacier ice shelf has been thinning rapidly since at least the early 1990s, which has caused its trunk to accelerate and retreat. Although the ice shelf front has remained stable for the past six decades, past periods of ice shelf collapse have been inferred from relict seabed “corrugations” (corrugated ridges), preserved 340 km from the glacier in Pine Island Trough. Here we present high-resolution bathymetry gathered by an autonomous underwater vehicle operating beneath an Antarctic ice shelf, which provides evidence of long-term change in Pine Island Glacier. Corrugations and ploughmarks on a sub-ice shelf ridge that was a former grounding line closely resemble those observed offshore, interpreted previously as the result of iceberg grounding. The same interpretation here would indicate a significantly reduced ice shelf extent within the last 11 kyr, implying Holocene glacier retreat beyond present limits, or a past tidewater glacier regime different from today. The alternative, that corrugations were not formed in open water, would question ice shelf collapse events interpreted from the geological record, revealing detail of another bed-shaping process occurring at glacier margins. We assess hypotheses for corrugation formation and suggest periodic grounding of ice shelf keels during glacier unpinning as a viable origin. This interpretation requires neither loss of the ice shelf nor glacier retreat and is consistent with a “stable” grounding-line configuration throughout the Holocene. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Iceberg* Pine Island Glacier Tidewater Natural Environment Research Council: NERC Open Research Archive Antarctic West Antarctic Ice Sheet Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) Pine Island Trough ENVELOPE(-101.841,-101.841,-75.011,-75.011) Shelf Ridge ENVELOPE(-127.754,-127.754,55.833,55.833) Journal of Geophysical Research: Earth Surface 118 3 1356 1366 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
topic |
Glaciology |
spellingShingle |
Glaciology Graham, Alastair G. C. Dutrieux, Pierre Vaughan, David G. Nitsche, Frank O. Gyllencreutz, Richard Greenwood, Sarah L. Larter, Robert D. Jenkins, Adrian Sea-bed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier |
topic_facet |
Glaciology |
description |
Ice shelves are critical features in the debate about West Antarctic ice sheet change and sea level rise, both because they limit ice discharge and because they are sensitive to change in the surrounding ocean. The Pine Island Glacier ice shelf has been thinning rapidly since at least the early 1990s, which has caused its trunk to accelerate and retreat. Although the ice shelf front has remained stable for the past six decades, past periods of ice shelf collapse have been inferred from relict seabed “corrugations” (corrugated ridges), preserved 340 km from the glacier in Pine Island Trough. Here we present high-resolution bathymetry gathered by an autonomous underwater vehicle operating beneath an Antarctic ice shelf, which provides evidence of long-term change in Pine Island Glacier. Corrugations and ploughmarks on a sub-ice shelf ridge that was a former grounding line closely resemble those observed offshore, interpreted previously as the result of iceberg grounding. The same interpretation here would indicate a significantly reduced ice shelf extent within the last 11 kyr, implying Holocene glacier retreat beyond present limits, or a past tidewater glacier regime different from today. The alternative, that corrugations were not formed in open water, would question ice shelf collapse events interpreted from the geological record, revealing detail of another bed-shaping process occurring at glacier margins. We assess hypotheses for corrugation formation and suggest periodic grounding of ice shelf keels during glacier unpinning as a viable origin. This interpretation requires neither loss of the ice shelf nor glacier retreat and is consistent with a “stable” grounding-line configuration throughout the Holocene. |
format |
Article in Journal/Newspaper |
author |
Graham, Alastair G. C. Dutrieux, Pierre Vaughan, David G. Nitsche, Frank O. Gyllencreutz, Richard Greenwood, Sarah L. Larter, Robert D. Jenkins, Adrian |
author_facet |
Graham, Alastair G. C. Dutrieux, Pierre Vaughan, David G. Nitsche, Frank O. Gyllencreutz, Richard Greenwood, Sarah L. Larter, Robert D. Jenkins, Adrian |
author_sort |
Graham, Alastair G. C. |
title |
Sea-bed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier |
title_short |
Sea-bed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier |
title_full |
Sea-bed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier |
title_fullStr |
Sea-bed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier |
title_full_unstemmed |
Sea-bed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier |
title_sort |
sea-bed corrugations beneath an antarctic ice shelf revealed by autonomous underwater vehicle survey: origin and implications for the history of pine island glacier |
publisher |
American Geophysical Union |
publishDate |
2013 |
url |
http://nora.nerc.ac.uk/id/eprint/502340/ https://nora.nerc.ac.uk/id/eprint/502340/1/jgrf20087.pdf https://doi.org/10.1002/jgrf.20087 |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) ENVELOPE(-101.841,-101.841,-75.011,-75.011) ENVELOPE(-127.754,-127.754,55.833,55.833) |
geographic |
Antarctic West Antarctic Ice Sheet Pine Island Glacier Pine Island Trough Shelf Ridge |
geographic_facet |
Antarctic West Antarctic Ice Sheet Pine Island Glacier Pine Island Trough Shelf Ridge |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Iceberg* Pine Island Glacier Tidewater |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Iceberg* Pine Island Glacier Tidewater |
op_relation |
https://nora.nerc.ac.uk/id/eprint/502340/1/jgrf20087.pdf Graham, Alastair G. C.; Dutrieux, Pierre orcid:0000-0002-8066-934X Vaughan, David G. orcid:0000-0002-9065-0570 Nitsche, Frank O.; Gyllencreutz, Richard; Greenwood, Sarah L.; Larter, Robert D. orcid:0000-0002-8414-7389 Jenkins, Adrian orcid:0000-0002-9117-0616 . 2013 Sea-bed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier. Journal of Geophysical Research: Earth Surface, 118 (3). 1356-1366. https://doi.org/10.1002/jgrf.20087 <https://doi.org/10.1002/jgrf.20087> |
op_doi |
https://doi.org/10.1002/jgrf.20087 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
118 |
container_issue |
3 |
container_start_page |
1356 |
op_container_end_page |
1366 |
_version_ |
1766248652389482496 |