Calibrated Seismic Imaging of Eddy-Dominated Warm-Water Transport across the Bellingshausen Sea, Southern Ocean
Seismic reflection images of thermohaline circulation from the Bellingshausen Sea, adjacent to the West Antarctica Peninsula, were acquired during February 2015. This survey shows that bright reflectivity occurs throughout the upper 300 m. By calibrating these seismic images with coeval hydrographic...
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ftucambridgeesc:oai:eprints.esc.cam.ac.uk:4250 2023-05-15T13:15:21+02:00 Calibrated Seismic Imaging of Eddy-Dominated Warm-Water Transport across the Bellingshausen Sea, Southern Ocean Gunn, Kathryn L. White, Nicky J. Larter, Robert D. Caulfield, Colm-cille P. 2018 text http://eprints.esc.cam.ac.uk/4250/ http://eprints.esc.cam.ac.uk/4250/1/gunn-et-al-2018-rev-v8.pdf http://eprints.esc.cam.ac.uk/4250/2/Gunn_et_al-2018-Journal_of_Geophysical_Research%253A_Oceans.pdf en eng AGU http://eprints.esc.cam.ac.uk/4250/1/gunn-et-al-2018-rev-v8.pdf http://eprints.esc.cam.ac.uk/4250/2/Gunn_et_al-2018-Journal_of_Geophysical_Research%253A_Oceans.pdf Gunn, Kathryn L. and White, Nicky J. and Larter, Robert D. and Caulfield, Colm-cille P. (2018) Calibrated Seismic Imaging of Eddy-Dominated Warm-Water Transport across the Bellingshausen Sea, Southern Ocean. Journal of Geophysical Research: Oceans. ISSN 2169-9291 02 - Geodynamics Geophysics and Tectonics Article PeerReviewed 2018 ftucambridgeesc 2020-08-27T18:09:55Z Seismic reflection images of thermohaline circulation from the Bellingshausen Sea, adjacent to the West Antarctica Peninsula, were acquired during February 2015. This survey shows that bright reflectivity occurs throughout the upper 300 m. By calibrating these seismic images with coeval hydrographic measurements, intrusion of warm water features onto the continental shelf at Marguerite and Belgica Troughs is identified and characterized. These features have distinctive lens‐shaped patterns of reflectivity with lengths of 0.75–11.00 km and thicknesses of 100–150 m, suggesting that they are small mesoscale to submesoscale eddies. Abundant eddies are observed along a transect that crosses Belgica Trough. Near Alexander Island Drift, a large, of order urn:x-wiley:21699275:media:jgrc22803:jgrc22803-math-0001 km3, bowl‐like feature, that may represent an anticyclonic Taylor column, is imaged on a pair of orthogonal images. A modified iterative procedure is used to convert seismic imagery into maps of temperature that enable the number and size of eddies being transported onto the shelf to be quantified. Finally, analysis of prestack shot records suggests that these eddies are advecting southward at speeds of urn:x-wiley:21699275:media:jgrc22803:jgrc22803-math-0002 m s−1, consistent with limited legacy hydrographic measurements. Concentration of observed eddies south of the Southern Antarctic Circumpolar Current Front implies they represent both a dominant, and a long‐lived, mechanism of warm‐water transport, especially across Belgica Trough. Our observations suggest that previous estimates of eddy frequency may have been underestimated by up to 1 order of magnitude, which has significant implications for calculations of ice mass loss on the shelf of the West Antarctic Peninsula. Article in Journal/Newspaper Alexander Island Antarc* Antarctic Antarctic Peninsula Antarctica Bellingshausen Sea Southern Ocean West Antarctica University of Cambridge, Department of Earth Sciences: ESC Publications Alexander Island ENVELOPE(-69.895,-69.895,-71.287,-71.287) Antarctic Antarctic Peninsula Bellingshausen Sea Marguerite ENVELOPE(141.378,141.378,-66.787,-66.787) Southern Ocean West Antarctica |
institution |
Open Polar |
collection |
University of Cambridge, Department of Earth Sciences: ESC Publications |
op_collection_id |
ftucambridgeesc |
language |
English |
topic |
02 - Geodynamics Geophysics and Tectonics |
spellingShingle |
02 - Geodynamics Geophysics and Tectonics Gunn, Kathryn L. White, Nicky J. Larter, Robert D. Caulfield, Colm-cille P. Calibrated Seismic Imaging of Eddy-Dominated Warm-Water Transport across the Bellingshausen Sea, Southern Ocean |
topic_facet |
02 - Geodynamics Geophysics and Tectonics |
description |
Seismic reflection images of thermohaline circulation from the Bellingshausen Sea, adjacent to the West Antarctica Peninsula, were acquired during February 2015. This survey shows that bright reflectivity occurs throughout the upper 300 m. By calibrating these seismic images with coeval hydrographic measurements, intrusion of warm water features onto the continental shelf at Marguerite and Belgica Troughs is identified and characterized. These features have distinctive lens‐shaped patterns of reflectivity with lengths of 0.75–11.00 km and thicknesses of 100–150 m, suggesting that they are small mesoscale to submesoscale eddies. Abundant eddies are observed along a transect that crosses Belgica Trough. Near Alexander Island Drift, a large, of order urn:x-wiley:21699275:media:jgrc22803:jgrc22803-math-0001 km3, bowl‐like feature, that may represent an anticyclonic Taylor column, is imaged on a pair of orthogonal images. A modified iterative procedure is used to convert seismic imagery into maps of temperature that enable the number and size of eddies being transported onto the shelf to be quantified. Finally, analysis of prestack shot records suggests that these eddies are advecting southward at speeds of urn:x-wiley:21699275:media:jgrc22803:jgrc22803-math-0002 m s−1, consistent with limited legacy hydrographic measurements. Concentration of observed eddies south of the Southern Antarctic Circumpolar Current Front implies they represent both a dominant, and a long‐lived, mechanism of warm‐water transport, especially across Belgica Trough. Our observations suggest that previous estimates of eddy frequency may have been underestimated by up to 1 order of magnitude, which has significant implications for calculations of ice mass loss on the shelf of the West Antarctic Peninsula. |
format |
Article in Journal/Newspaper |
author |
Gunn, Kathryn L. White, Nicky J. Larter, Robert D. Caulfield, Colm-cille P. |
author_facet |
Gunn, Kathryn L. White, Nicky J. Larter, Robert D. Caulfield, Colm-cille P. |
author_sort |
Gunn, Kathryn L. |
title |
Calibrated Seismic Imaging of Eddy-Dominated Warm-Water Transport across the Bellingshausen Sea, Southern Ocean |
title_short |
Calibrated Seismic Imaging of Eddy-Dominated Warm-Water Transport across the Bellingshausen Sea, Southern Ocean |
title_full |
Calibrated Seismic Imaging of Eddy-Dominated Warm-Water Transport across the Bellingshausen Sea, Southern Ocean |
title_fullStr |
Calibrated Seismic Imaging of Eddy-Dominated Warm-Water Transport across the Bellingshausen Sea, Southern Ocean |
title_full_unstemmed |
Calibrated Seismic Imaging of Eddy-Dominated Warm-Water Transport across the Bellingshausen Sea, Southern Ocean |
title_sort |
calibrated seismic imaging of eddy-dominated warm-water transport across the bellingshausen sea, southern ocean |
publisher |
AGU |
publishDate |
2018 |
url |
http://eprints.esc.cam.ac.uk/4250/ http://eprints.esc.cam.ac.uk/4250/1/gunn-et-al-2018-rev-v8.pdf http://eprints.esc.cam.ac.uk/4250/2/Gunn_et_al-2018-Journal_of_Geophysical_Research%253A_Oceans.pdf |
long_lat |
ENVELOPE(-69.895,-69.895,-71.287,-71.287) ENVELOPE(141.378,141.378,-66.787,-66.787) |
geographic |
Alexander Island Antarctic Antarctic Peninsula Bellingshausen Sea Marguerite Southern Ocean West Antarctica |
geographic_facet |
Alexander Island Antarctic Antarctic Peninsula Bellingshausen Sea Marguerite Southern Ocean West Antarctica |
genre |
Alexander Island Antarc* Antarctic Antarctic Peninsula Antarctica Bellingshausen Sea Southern Ocean West Antarctica |
genre_facet |
Alexander Island Antarc* Antarctic Antarctic Peninsula Antarctica Bellingshausen Sea Southern Ocean West Antarctica |
op_relation |
http://eprints.esc.cam.ac.uk/4250/1/gunn-et-al-2018-rev-v8.pdf http://eprints.esc.cam.ac.uk/4250/2/Gunn_et_al-2018-Journal_of_Geophysical_Research%253A_Oceans.pdf Gunn, Kathryn L. and White, Nicky J. and Larter, Robert D. and Caulfield, Colm-cille P. (2018) Calibrated Seismic Imaging of Eddy-Dominated Warm-Water Transport across the Bellingshausen Sea, Southern Ocean. Journal of Geophysical Research: Oceans. ISSN 2169-9291 |
_version_ |
1766268166291324928 |