| PALEOCEANOGRAPHY |
Equatorial Pacific Multispecies Foraminifera Stable Isotope Data
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Spero, H.J., K.M. Mielke, E.M. Kalve, D.W. Lea, and D.K. Pak. 2003. Multispecies approach to reconstructing eastern equatorial
Pacific thermocline hydrography during the past 360 kyr. Paleoceanography 18(1), 1022.
| Data Coverage |
North: 2.25 * South: 2.25 |
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West: -90.95 * East: -90.95 |
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Altitude: -2348 m |
Start Year: 361000 14C yr BP
* End Year: 1100 14C yr BP
Data: Please Cite Data Contributors!
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Summary: Stable isotope data from eastern equatorial Pacific (EEP) core TR163-19 (2°15'N, 90°57'W, 2348 m) are presented for the surface-dwelling
foraminifers Globigerinoides ruber and G. sacculifer and thermocline-dwelling Globorotalia menardii and Neogloboquadrina dutertrei.
Using species-specific normalization factors derived from experimental and plankton tow data, we reconstruct a 360 kyr record
of water column hydrography across the past three glacial cycles. We demonstrate that G. ruber maintains a mixed layer habitat
throughout the entire record, while G. sacculifer records a mixture of thermocline and mixed layer conditions and G. menardii
and N. dutertrei record thermocline properties. We conclude that G. sacculifer is not appropriate for paleoceanographic applications
in regions with steep vertical hydrographic gradients. Results suggest that this region of the EEP had a thicker mixed layer
and deeper d13CDIC boundary between the surface and equatorial undercurrent during the last two glacial periods. A shift in
N. dutertrei and G. sacculifer geochemistry prior to ~185 kyr suggests water column structure and chemocline gradients changed,
possibly due to a shift in the position of the undercurrent relative to this site. The timing and magnitude of glacial-interglacial
d13C variations between species indicates that near-surface carbon chemistry is controlled by changes in productivity, atmospheric
circulation, and advected intermediate water sources north of the Antarctic polar front. These results demonstrate that when
properly calibrated for species differences, multispecies geochemical data sets can be invaluable for reconstructing water
column structure and properties in the past.
More Info on Paleoceanography Data |
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Parameters: delta C13 PDB (Globigerinoides sacculifer >500 micron); radiocarbon years before 1950AD; delta C13 PDB (Globigerinoides sacculifer 250-350 micron); delta O18 PDB (Globigerinoides sacculifer 250-350 micron); delta O18 PDB (Neogloboquadrina dutertrei); delta C13 PDB (Globigerinoides ruber 250-350 micron); delta O18 PDB (Globigerinoides ruber 250-350 micron); delta O18 PDB (Globorotalia menardii); delta O18 PDB (Globigerinoides sacculifer >500 micron); delta C13 PDB (Neogloboquadrina dutertrei); delta C13 PDB (Globorotalia menardii)
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Complete XML Record: noaa-ocean-2635
(Last Revised: 2008-04-10 )
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| http://www.ncdc.noaa.gov/paleo/ |
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