Authors / CoAuthors
Post, A.L. | O'Brien, P.E. | Young, N.
Abstract
The production of icebergs from Antarctic ice shelves represents fluctuations in the mass of the icesheet. Mapping the age, distribution and size of iceberg scour marks on the seafloor provides insight into the dynamics of the icesheet and circulation patterns through time. Sidescan sonar records from the Prydz Bay continental shelf are used to determine the relative ages of scour marks on this shelf as modern, relict and very relict, and their width, length and orientation. Modern scour marks on this shelf are shown to occur at average depths of 285 m, up to a maximum of 400 m. This range is broadly consistent with modern keel depths (248-352 m) for icebergs produced from the Amery Ice Shelf. Relict scours occur at average depths of 486 ± 78 m, while very relict scours occur at average depths of 650 ± 60 m. No iceberg scours are observed at depths greater than 750 m. The depth range of relict scours is consistent with iceberg scouring during periods of lower glacial sea level, combined with the production of icebergs with larger keel depths during major deglaciations. The very deep setting of the oldest scours implies the production of icebergs from a very thick iceshelf, possibly relating to major retreat of the icesheet towards the grounding line during periods of extreme glacial retreat.
Product Type
nonGeographicDataset
eCat Id
70260
Contact for the resource
Custodian
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Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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- External PublicationAbstract
- ( Theme )
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- Antarctic data
- ( Theme )
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- morphology
- ( Theme )
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- seabed
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- AQ
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_Internal
Publication Date
2010-01-01T00:00:00
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geoscientificInformation
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