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Holocene sediment record of Antarctic deep water production

Objective

Two recently surveyed, adjacent deep inner-shelf basins along the Wilkes Land sector of East Antarctica are suitable sites for paleoclimatic studies, since high sedimentation rates of diatomaceous mud and ooze locally generated high-resolution records spanning the last few thousand years. The study areas comprise coastal glaciers that represent seaward terminations of a sector of the East Antarctic Ice Sheet, investigated by an Italian-French Ice Core project, which recovered data up to 920,000 years old (E PICA-DC). Geo-marine cruises targeted the two areas, revealing similarities and differences in terms of Holocene sedimentation patterns, which we aim at analysing further. The George V Basin on the east (142°-150° E) has been dominated by production of High Salinity Shelf Water (HSSW) during the Late Holocene after a phase of mid-Holocene low deep-water ventilation.

The production of HSSW switched on and almost off at least twice during the Holocene. Oxic and anoxic intervals, observed in the George V Basin Holocene sediment intervals, can be related to different periods of production of HSSW from the lee side of the Mertz Glacier floating ice tongue. Instead, the Adelie Basin on the west (136°-140° E) was not influenced by strong circulation variations, keeping a high-resolution, expanded oceanographic and climatic record in the form of up to 200m thick Holocene sediments, which we aim at analysing for their content of major, minor and redox-sensitive elements. We would like to investigate: the relationship between the factors controlling the HSSW production, cold versus warm stratigraphic units in the Adelie Basin, sediment sources feeding the coring sites during the Holocene. Such a study of the whole margin would provide useful insights for understanding t he relationship between warm/cold periods, production of HSSW and global circulation. Direct correlation can be made between the EPICA-Dome C ice core and the sediment core datasets.

Call for proposal

FP6-2004-MOBILITY-11
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Funding Scheme

ERG - Marie Curie actions-European Re-integration Grants

Coordinator

NATIONAL INSTITUTE OF OCEANOGRAPHY AND EXPERIMENTAL GEOPHYSICS
Address
Borgo Grotta Gigante 42/C
Sgonico, Trieste
Italy