Bathymetry and acoustic facies beneath the former Larsen-A and Prince Gustav ice shelves, north-west Weddell Sea

• Published in: Antarctic Science
• Main Authors: Pudsey, Carol J., Evans, Jeffrey, Domack, Eugene W., Morris, Peter, Valle, Rodolfo A. Del
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2001
• Subjects: Geology; Ecology, Evolution, Behavior and Systematics; Oceanography; Weddell Sea; Weddell; Prince Gustav Channel; Larsen Inlet; Antarctic Science; Ice Shelf; Ice Shelves
• Online Access: http://dx.doi.org/10.1017/s095410200100044x; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S095410200100044X

We present preliminary results of the first detailied surveys of the former Larsen-A Ice Shelf, Larsen Inlet and southern Prince Gustav Channel, where disintegration of small ice shelves in the past ten years has exposed the seafloor. Glacial troughs in the Larsen-A area, Larsen Inlet and Prince Gustav Channel reach 900–1100 m depth and have hummocky floors. Farther south-east, the continental shelf is shallower (400–500 m) and its surface is fluted to smooth, with the density of iceberg furrowing increasing towards the shelf edge. Acoustic profiles show a drape of transparent sediment 4–8 m thick in Prince Gustav Channel, thinning southwards. In cores, this drape corresponds to diatom-bearing marine and glacial-marine mud. In the Larsen-A area and Larsen Inlet, acoustically opaque sediment includes proximal ice shelf glaciomarine gravelly and sandy muds, and firm to stiff diamicts probably deposited subglacilly. These are overlain by thin (up to 1.3 m) glaciomarine muds, locally with distinctive diatom ooze laminae.