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| Titel |
A new bathymetric compilation for the South Orkney Islands, Antarctic Peninsula (49°- 39°W to 64°- 59°S): insights into the glacial development of the continental shelf |
| VerfasserIn |
William Dickens, Alastair Graham, James Smith, Julian Dowdeswell, Robert Larter, Claus-Dieter Hillenbrand, Phil Trathan, Jan Arndt |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250096241
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| Publikation (Nr.) |
 EGU/EGU2014-11735.pdf |
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| Zusammenfassung |
| We present a new, high resolution (300 m) bathymetric grid of the South Orkney
Islands and surrounding continental shelf, northeast of the Antarctic Peninsula.
The new grid, derived from a compilation of marine echo-sounding data offers
significant and demonstrable improvements over previous regional bathymetric
representations and helps to visualise the morphology of the shelf in unrivalled detail. With
multiple end users (oceanographers, glacial modellers, biologists and geologists) the
new compilation forms important baseline information for a range of scientific
applications. In particular, due to our limited understanding of glacial history in this
region, the new bathymetry grid provides the first detailed insights into past glacial
regimes. The continental shelf is dominated by seven glacially eroded troughs,
marking the pathways of glacial outlets that once drained a former ice cap centered on
the South Orkney Islands. During previous glacial periods, grounded ice extended
to the shelf break to the north of the islands. A large, ~ 250 km long sediment
depocenter, interpreted as a maximum former ice limit of one or more Cenozoic
glaciations, suggests that ice was only grounded to the ~ 300 m contour in the South.
Using observations from the new bathymetric grid, we propose a preliminary ice cap
reconstruction for maximum glaciation of the South Orkney plateau suggesting an areal ice
coverage in the region of ~ 19000 km2. The timing of maximum ice extent, number of
past advances and pattern of subsequent deglaciation(s) remain uncertain and will
require further targeted marine geological and geophysical investigations to resolve. |
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