Calibrated Seismic Imaging of Eddy-Dominated Warm-Water Transport across the Bellingshausen Sea, Southern Ocean ...

• Main Authors: Gunn, Kathryn, White, NJ, Larter, RD, Caulfield, Colm-Cille Patrick
• Format: Article in Journal/Newspaper
• Language: English
• Published: Apollo - University of Cambridge Repository 2018
• Subjects: Alexander Island; Bellingshausen Sea; Marguerite; Southern Ocean; West Antarctica; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.17863/cam.22086; https://www.repository.cam.ac.uk/handle/1810/275156

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 sub-mesoscale eddies. Abundant eddies are observed along a transect that crosses Belgica Trough. Near Alexander Island drift, a large, $O(10^{2})$ km$^3$, 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 ...