| PALEOCEANOGRAPHY |
Tasmanian Gateway ODP Leg 189 Sediment Data and SST Reconstructions
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Nuernberg, D., N. Brughmans, J. Schönfeld, U.S. Ninnemann, and C. Dullo. 2004. Paleo-export productivity, terrigenous flux,
and sea surface temperature around Tasmania - Implications for glacial/interglacial changes in the Subtropical Convergence
Zone. in Exon, N., J.P. Kennett, and M. Malone (eds.) The Cenozic Southern Ocean:Tectonics, Sedimentation and Climate Change
Between Australia and Antarctica. Geophysical Monograph Series, 151, 291-318.
| Data Coverage |
North: -42.6 * South: -48.5 |
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West: 49.93 * East: 149.1 |
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Altitude: -2705 m |
Start Year: 605730 14C yr BP
* End Year: 0 14C yr BP
Data: Please Cite Data Contributors!
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Summary: The Tasmanian Gateway, focus of ODP Leg 189, is a key oceanographic area within the Southern Ocean. Our investigations concentrate
on the last ~500,000 years of sedimentation at Sites 1168 (western Tasmanian margin), 1170 and 1171 (Tasman Rise), and 1172
(East Tasman Plateau). A suite of geochemical proxy reflecting paleo-export production, terrigenous flux, and sea surface
temperature, constrain temporal and spatial variations in surface water masses and oceanographic frontal systems over these
sites. Interglacial periods were commonly of low productivity and less affected by terrigenous matter supply, suggesting
that the position of the Subtropical Convergence remained south of Tasman Rise. Only during MIS11and MIS9 over the southern
Tasman Rise, and during MIS7 over the northern Tasman Rise, did enhanced marine productivity, combined with an enhanced terrigenous
flux, indicate waxing influence of subantarctic waters. During glacial MIS2, marine productivity and terrigenous flux increased
significantly at sites 1168, 1170, and 1171 implying that the Subtropical Convergence moved northward to ~42S west of Tasmania.
East of Tasmania, the presence of the East Australian Current caused the Subtropical Convergence to remain south of East Tasman
Plateau. Glacial MIS6 appears to have been different from MIS2. The Subtropical Convergence stayed north of East Tasman
Plateau, but clearly south of Site 1168 on the western Tasmanian margin. Strongly enhanced marine productivity and terrigenous
flux during MIS10 and MIS12 at Sites 1168, 1170, and 1172 suggest the dominant influence of subantarctic waters and the position
of the Subtropical Convergence north of the East Tasman Plateau. At South Tasman Rise, in contrast, the reduced terrigenous
flux implies that Site 1171 moved outside the belt of westerly winds. Marine productivity ceased at that time mainly due
to iron limitation.
More Info on Paleoceanography Data |
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Parameters: Iron (µmol/g); Titanium (µmol/g); Chlorins (µg/g); Total organic carbon percent; Coarse Calcium Carbonate percent; Siliciclast percent; Magnesium/Calcium ratio replicate; Sediment lightness (L*), CIE scale; Aluminum (µmol/g); delta O18 PDB (Cibicidoides wuellerstorfi); Magnesium/Calcium ratio (Globigerina Bulloides); Sea surface temperature from Mg/Ca; Calcium Carbonate percent; Magnetic Susceptibility; radiocarbon years before 1950AD; delta O18 PDB (Globigerina bulloides)
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Complete XML Record: noaa-ocean-5597
(Last Revised: 2007-12-21 )
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DOC/NOAA/NESDIS/NCDC (National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce )
325 Broadway, E/CC23
Boulder, CO 80305
USA
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| http://www.ncdc.noaa.gov/paleo/ |
| E-mail: bruce.a.bauer@noaa.gov |
| E-mail: paleo@noaa.gov |
Phone: 303-497-6280
Fax: 303-497-6513
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