Data Description

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Citation:
Benthien, A et al. (2002): Delta 13C measured on alkenones of surface sediment samples GeoB1008-6 to GeoB3603-1 from the South Atlantic. doi:10.1594/PANGAEA.63632,
Supplement to: Benthien, Albert; Andersen, Nils; Schulte, Sonja; Müller, Peter J; Schneider, Ralph R; Wefer, Gerold (2002): Carbon isotopic composition of the C37:2 alkenone in core-top sediments of the South Atlantic Ocean: Effects of CO2 and nutrient concentrations. Global Biogeochemical Cycles, 16(1), 1012, doi:10.1029/2001GB001433
Abstract:
We have analyzed the stable carbon isotopic composition of the diunsaturated C37 alkenone in 29 surface sediments from the equatorial and South Atlantic Ocean. Our study area covers different oceanographic settings, including sediments from the major upwelling regions off South Africa, the equatorial upwelling, and the oligotrophic western South Atlantic. In order to examine the environmental influences on the sedimentary record the alkenone-based carbon isotopic fractionation (Ep) values were correlated with the overlying surface water concentrations of aqueous CO2 ([CO2(aq)]), phosphate, and nitrate. We found Ep positively correlated with 1/[CO2(aq)] and negatively correlated with [PO43-] and [NO3-]. However, the relationship between Ep and 1/[CO2(aq)] is opposite of what is expected from a [CO2(aq)] controlled, diffusive uptake model. Instead, our findings support the theory of Bidigare et al. (1997, doi:10.1029/96GB03939) that the isotopic fractionation in haptophytes is related to nutrient-limited growth rates. The relatively high variability of the Ep-[PO4] relationship in regions with low surface water nutrient concentrations indicates that here other environmental factors also affect the isotopic signal. These factors might be variations in other growth-limiting resources such as light intensity or micronutrient concentrations.
Project(s):
Geosciences, University of Bremen (GeoB) *
Coverage:
Median Latitude: -13.404206 * Median Longitude: -10.443734 * South-bound Latitude: -35.121667 * West-bound Longitude: -45.870000 * North-bound Latitude: 5.333333 * East-bound Longitude: 17.533333
Minimum DEPTH, sediment/rock: 0.0 m * Maximum DEPTH, sediment/rock: 0.0 m
Event(s):
GeoB1008-6 * * Latitude: -6.593983 * Longitude: 10.318800 * Date/Time: 1988-02-21T00:00:00 * Elevation: -3100.0 m * Recovery: 0.43 m * Penetration: 0.45 m * Location: Walvis Ridge * * Campaign: M6/6 * * Basis: Meteor (1986) * * Device: Giant box corer * * Comment: Tonschlamm, braungrau
GeoB1016-3 * * Latitude: -11.770500 * Longitude: 11.681900 * Date/Time: 1988-02-25T00:00:00 * Elevation: -3411.0 m * Recovery: 12.41 m * Penetration: 18.00 m * Location: Angola Basin * * Campaign: M6/6 * * Basis: Meteor (1986) * * Device: Gravity corer (Kiel type) * * Comment: cc: Ton, grüngrau
GeoB1028-4 * * Latitude: -20.099333 * Longitude: 9.177667 * Date/Time: 1988-03-02T00:00:00 * Elevation: -2215.0 m * Recovery: 0.35 m * Penetration: 0.37 m * Location: Walvis Ridge * * Campaign: M6/6 * * Basis: Meteor (1986) * * Device: Giant box corer * * Comment: Karb.-sand, Forams.
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Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethodComment
1Event labelEventMetadata
2LATITUDE *LatitudeGeocode
3LONGITUDE *LongitudeGeocode
4Elevation of eventElevationmMetadata
5DEPTH, sediment/rock *DepthmGeocode
6Alkenone, unsaturation index UK37 *UK37Benthien, Albert *calculated *calculated after Müller et al, (1998, doi:10.1016/S0016-7037(98)00097-0), Bentien and Müller (2000, doi:10.1016/S0967-0637(00)00030-3)
7Sea surface temperature, annual mean *SST (1-12)°CBenthien, Albert *
8Alkenone C37:2, d13C *C37:2 d13Cper mil PDBBenthien, Albert *Mass spectrometer Finnigan MAT 252 *
9Alkenone, Ep *Epper mil PDBBenthien, Albert *Gas chromatography *
10Carbon dioxide, total *TCO2µmol/lBenthien, Albert *calculated *
11Carbon dioxide, total *TCO2µmol/lBenthien, Albert *calculated *Angola Coastal Current and Benguela Coastal Current provinces at 70 ppmv correction values
12- *Benthien, Albert *calculated *b-value in per mil µmol/L
13- *Benthien, Albert *calculated *b-value in per mil µmol/L, Angola Coastal Current and Benguela Coastal Current provinces at 70 ppmv correction values
14Phosphate *PO4µmol/lBenthien, Albert *from World Ocean Atlas 1994
15Nitrate *NO3µmol/lBenthien, Albert *from World Ocean Atlas 1994
License:
CC-BY Creative Commons Attribution 3.0 Unported
Size:
249 data points

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