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...
Published in: | Journal of Geophysical Research: Oceans |
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ftsouthampton:oai:eprints.soton.ac.uk:483317 2023-12-03T10:09:05+01:00 Calibrated seismic imaging of eddy-dominated warm-water transport across the Bellingshausen Sea, Southern Ocean Gunn, K.L. White, N.J. Larter, R.D. Caulfield, C.P. 2018-04-30 https://eprints.soton.ac.uk/483317/ English eng Gunn, K.L., White, N.J., Larter, R.D. and Caulfield, C.P. (2018) Calibrated seismic imaging of eddy-dominated warm-water transport across the Bellingshausen Sea, Southern Ocean. Journal of Geophysical Research: Oceans, 123 (4), 2315-3116. (doi:10.1029/2018jc013833 <http://dx.doi.org/10.1029/2018jc013833>). Article PeerReviewed 2018 ftsouthampton https://doi.org/10.1029/2018jc013833 2023-11-03T00:10:16Z 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 Southampton: e-Prints Soton Antarctic Southern Ocean Antarctic Peninsula West Antarctica Bellingshausen Sea Marguerite ENVELOPE(141.378,141.378,-66.787,-66.787) Alexander Island ENVELOPE(-69.895,-69.895,-71.287,-71.287) Journal of Geophysical Research: Oceans 123 4 3072 3099 |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
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, K.L. White, N.J. Larter, R.D. Caulfield, C.P. |
spellingShingle |
Gunn, K.L. White, N.J. Larter, R.D. Caulfield, C.P. Calibrated seismic imaging of eddy-dominated warm-water transport across the Bellingshausen Sea, Southern Ocean |
author_facet |
Gunn, K.L. White, N.J. Larter, R.D. Caulfield, C.P. |
author_sort |
Gunn, K.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 |
publishDate |
2018 |
url |
https://eprints.soton.ac.uk/483317/ |
long_lat |
ENVELOPE(141.378,141.378,-66.787,-66.787) ENVELOPE(-69.895,-69.895,-71.287,-71.287) |
geographic |
Antarctic Southern Ocean Antarctic Peninsula West Antarctica Bellingshausen Sea Marguerite Alexander Island |
geographic_facet |
Antarctic Southern Ocean Antarctic Peninsula West Antarctica Bellingshausen Sea Marguerite Alexander Island |
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 |
Gunn, K.L., White, N.J., Larter, R.D. and Caulfield, C.P. (2018) Calibrated seismic imaging of eddy-dominated warm-water transport across the Bellingshausen Sea, Southern Ocean. Journal of Geophysical Research: Oceans, 123 (4), 2315-3116. (doi:10.1029/2018jc013833 <http://dx.doi.org/10.1029/2018jc013833>). |
op_doi |
https://doi.org/10.1029/2018jc013833 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
123 |
container_issue |
4 |
container_start_page |
3072 |
op_container_end_page |
3099 |
_version_ |
1784261831966064640 |