Prydz Bay sediment drifts: Archives of modifications in East Antarctic climatic and oceanographic conditions
The detailed onset of the Antarctic glaciation during the Eocene/Oligocene and the later ice sheet dynamic in response to warm phases during the Miocene and Pliocene is still under discussion. Attempts to solve the open questions by scientific drilling have been limited by the fact that early Oligoc...
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| Format: | Conference Object |
| Language: | unknown |
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2018
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| Online Access: | https://epic.awi.de/id/eprint/46192/ https://hdl.handle.net/10013/epic.51a5179a-bd6e-406e-adc8-fdc9bf8d8232 |
| Summary: | The detailed onset of the Antarctic glaciation during the Eocene/Oligocene and the later ice sheet dynamic in response to warm phases during the Miocene and Pliocene is still under discussion. Attempts to solve the open questions by scientific drilling have been limited by the fact that early Oligocene to early Miocene sediments, which bear witness to the onset of glaciation and early dynamics of the ice sheet, have been eroded from the continental shelf or are buried below thick Neogene sequences and could thus not be sampled during ODP Legs 119 and 188. Several hypotheses place the onset of bottom water formation as the result of down welling due to strong cooling into the Miocene, the late Oligocene, or the late Eocene, which shows the range of uncertainty in dating this event. The dynamical response, e.g., of the Lambert Glacier-Amery Ice Shelf drainage system to climate variability is recorded in the sediments of Prydz Bay and the adjacent slope and rise of the Cooperation Sea. Thus a study of sedimentary features and structures and the prevailing sediment transport patterns can help to understand the development of this system and its sensitivity to climate change. The analysis of seismic reflection data allows to reconstruct sediment input and sediment transport patterns. This represents an important tool, even if an indirect one, to infer past changes in climate and oceanography in the absence of direct information from drilled geological samples. A large dataset of high-quality seismic lines has been acquired along the Prydz Bay margin, is available via the SCAR seismic data library system and will be analysed with respect to documents of down-slope, i.e., the result of material input via advancing the ice sheet, and along-slope, i.e., features resulting from the shaping of bottom and deep water, to infer past changes in climate and oceanography in combination with results from ODP Leg 119 and 188. This way we also intend to close the gap, which could not be sampled by drilling (the early Oligocene to early Miocene). |
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