Data Description

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Citation:
Schulte, S et al. (2004): (Table 4) Estimated surface water phosphate concentrations for the past 200 kyr at the location of sediment core GeoB1016-3. Dataset #841219 (DOI registration in progress),
Supplement to: Schulte, Sonja; Benthien, Albert; Müller, Peter J; Rühlemann, Carsten (2004): Carbon isotopic fractionation (ep) of C37 alkenones in deep-sea sediments: Its potential as a paleonutrient proxy. Paleoceanography, 19(1), PA1011, doi:10.1029/2002PA000811
Abstract:
We compared ocean atlas values of surface water [PO4]3- and [CO2(aq)] against the carbon isotopic fractionation (ep) of alkenones obtained from surface sediments of the South Atlantic and the central Pacific (Pacific data are from Pagani et al. 2002, doi:10.1029/2002PA000756). We observed a positive correlation between ep and 1/[CO2(aq)], which is opposite of what would be expected if the concentration of CO2(aq) were the major factor controlling the carbon isotopic fractionation of C37:2 alkenones. Instead, we found inverse relationships between ep and [PO4]3- for the two ocean basins (for the Atlantic, ep = -4.6*[PO4]3- + 15.1, R = 0.76; for the Pacific, ep = -4.1*[PO4]3- + 13.7, R = 0.64), suggesting that ep is predominantly controlled by growth rate, which in turn is related to nutrient concentration. The similarity of the slopes implies that a general relationship between both parameters may exist. Using the relationship obtained from the South Atlantic, we estimated surface water nutrient concentrations for the past 200,000 years from a deep-sea sediment core recovered off Angola. Low ep values, indicating high nutrient concentrations, coincide with high contents of total organic carbon and C37 alkenones, low surface water temperatures, and decreased bulk d15N values, suggesting an increased upwelling of nutrient-rich cool subsurface waters as the main cause for the observed ep decrease.
Related to:
Andersen, Nils; Müller, Peter J; Kirst, Georg; Schneider, Ralph R (1999): Alkenone d13C as a Proxy for Past PCO2 in Surface Waters: Results from the Late Quaternary Angola Current. In: Fischer, G & Wefer, G (eds.), Use of Proxies in Paleoceanography - Examples from the South Atlantic, Springer, Berlin, Heidelberg, 469-488 *
Coverage:
Latitude: -11.770500 * Longitude: 11.681900
Event(s):
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) (SL) * * Comment: cc: Ton, grüngrau
Comment:
Modern annual mean phosphate concentration at this location is µM (Conkright et al., 1994).
Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethodComment
1AGE *Ageka BPGeocode
2Alkenone, Ep *Epper mil PDBSchulte, Sonja *from Andersen et al. (1999)
3Phosphate *PO4µmol/lSchulte, Sonja *Estimated *
License:
Size:
58 data points

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