Past ice sheet–seabed interactions in the northeastern Weddell Sea embayment, Antarctica

Author:

Arndt Jan ErikORCID,Larter Robert D.ORCID,Hillenbrand Claus-Dieter,Sørli Simon H.,Forwick MatthiasORCID,Smith James A.,Wacker LukasORCID

Abstract

Abstract. The Antarctic ice sheet extent in the Weddell Sea embayment (WSE) during the Last Glacial Maximum (LGM; ca. 19–25 calibrated kiloyears before present, ka cal BP) and its subsequent retreat from the shelf are poorly constrained, with two conflicting scenarios being discussed. Today, the modern Brunt Ice Shelf, the last remaining ice shelf in the northeastern WSE, is only pinned at a single location and recent crevasse development may lead to its rapid disintegration in the near future. We investigated the seafloor morphology on the northeastern WSE shelf and discuss its implications, in combination with marine geological records, to create reconstructions of the past behaviour of this sector of the East Antarctic Ice Sheet (EAIS), including ice–seafloor interactions. Our data show that an ice stream flowed through Stancomb-Wills Trough and acted as the main conduit for EAIS drainage during the LGM in this sector. Post-LGM ice stream retreat occurred stepwise, with at least three documented grounding-line still-stands, and the trough had become free of grounded ice by ∼10.5 ka cal BP. In contrast, slow-flowing ice once covered the shelf in Brunt Basin and extended westwards toward McDonald Bank. During a later time period, only floating ice was present within Brunt Basin, but large “ice slabs” enclosed within the ice shelf occasionally ran aground at the eastern side of McDonald Bank, forming 10 unusual ramp-shaped seabed features. These ramps are the result of temporary ice shelf grounding events buttressing the ice further upstream. To the west of this area, Halley Trough very likely was free of grounded ice during the LGM, representing a potential refuge for benthic shelf fauna at this time.

Funder

Deutsche Forschungsgemeinschaft

Publisher

Copernicus GmbH

Subject

Earth-Surface Processes,Water Science and Technology

Reference62 articles.

1. Alley, R. B., Blankenship, D. D., Bentley, C. R., and Rooney, S. T.: Deformation of till beneath ice stream B, West Antarctica, Nature, 322, 57–59, https://doi.org/10.1038/322057a0, 1986.

2. Alley, R. B., Blankenship, D. D., Rooney, S. T., and Bentley, C. R.: Sedimentation beneath ice shelves – the view from ice stream B, Mar. Geol., 85, 101–120, https://doi.org/10.1016/0025-3227(89)90150-3, 1989.

3. Anderson, J. B. and Andrews, J. T.: Radiocarbon constraints on ice sheet advance and retreat in the Weddell Sea, Antarctica, Geology, 27, 179–182, https://doi.org/10.1130/0091-7613(1999)027<0179:RCOISA>2.3.CO;2, 1999.

4. Anderson, J. B., Kurtz, D. D., Domack, E. W., and Balshaw, K. M.: Glacial and Glacial Marine Sediments of the Antarctic Continental Shelf, J. Geol., 88, 399–414, https://doi.org/10.1086/628524, 1980.

5. Anderson, J. B., Davis, S. B., Domack, E., Kurtz, D. D., Balshaw, K. M., and Wright, R.: Marine Sediment Core Descriptions: IWSOE 68, 69, 70, Deep Freeze 79, Department of Geology, Rice University, Houston, USA, 1981.

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