Ice shelf grounding zone features of western Prydz Bay, Antarctica sedimentary processes from seismic and sidescan images

Maintenance and Update Frequency: unknown Statement: Unknown Several grounding zone wedges were left on the floor and flanks of Prydz Channel in western Prydz Bay by the Lambert Glacier during the last glacial cycle. Seismic profiles indicate that vertical accretion at the glacier bed was the most i...

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Bibliographic Details
Published in:Antarctic Science
Other Authors: BASFAW (custodian), Commonwealth of Australia (Geoscience Australia) (owner), Commonwealth of Australia (Geoscience Australia) (pointOfContact), De Santis, L. (author), Domack, E. (author), EGD (hasAssociationWith), Harris, P.T. (author), Manager Client Services (distributor), Manager Client Services (custodian), O'Brien, P.E. (author), Quilty, P.G. (author)
Format: Text
Language:unknown
Published: Australian Ocean Data Network
Subjects:
AQ
Online Access:https://researchdata.edu.au/ice-shelf-grounding-sidescan-images/683837
https://pid.geoscience.gov.au/dataset/ga/61483
https://doi.org/10.1017/S0954102099000115
Description
Summary:Maintenance and Update Frequency: unknown Statement: Unknown Several grounding zone wedges were left on the floor and flanks of Prydz Channel in western Prydz Bay by the Lambert Glacier during the last glacial cycle. Seismic profiles indicate that vertical accretion at the glacier bed was the most important depositional process in forming the wedges, rather than progradation by sediment gravity flows. Sidescan sonographs reveal extensive development of flutes on the sea floor inshore from the wedges, indicating deformable bed conditions beneath the ice. The region inshore of the east Prydz Channel wedge features extensive dune fields formed by currents flowing towards the grounding zone. This orientation is consistent with models of circulation beneath ice shelves in which melting at the grounding line generates plumes of fresher water that rise along the base of the ice shelf, entraining sea water into a circulation cell. The Lambert Deep is surrounded by a large composite ridge of glacial sediments. Internal reflectors suggest formation mostly by subglacial accretion. The sea floor in the Lambert Deep lacks dune fields and shows evidence of interspersed subglacial cavities and grounded ice beneath the glacier. The absence of bedforms reflects sea floor topography that would have inhibited the formation of energetic melt water-driven circulation.