Alkenones and SST of surface sediments (Appendix)

DOI

We have analysed alkenones in 149 surface sediments from the eastern South Atlantic in order to establish a sediment-based calibration of the U37K' paleotemperature index. Our study covers the major tropical to subpolar production systems and sea-surface temperatures (SST's) between 0° and 27°C. In order to define the most suitable calibration for this region, the U37K' values were correlated to seasonal, annual, and production-weighted annual mean atlas temperatures and compared to previously published culture and core-top calibrations. The best linear correlation between U37K' and SST was obtained using annual mean SST from 0 to 10 m water depth (U37K' = 0.033 T + 0.069, r2 = 0.981). Data scattering increased significantly using temperatures of waters deeper than 20 m, suggesting that U37K' reflects mixed-layer SST and that alkenone production at thermocline depths was not high enough to significantly bias the mixed-layer signal. Regressions based on both production-weighted and on actual annual mean atlas SST were virtually identical, indicating that regional variations in the seasonality of primary production have no discernible effect on the U37K' vs. SST relationship. Comparison with published core-top calibrations from other oceanic regions revealed a high degree of accordance. We, therefore, established a global core-top calibration using U37K' data from 370 sites between 60°S and 60°N in the Atlantic, Indian, and Pacific Oceans and annual mean atlas SST (0-29°C) from 0 m water depth. The resulting relationship (U37K' = 0.033 T + 0.044, r2 = 958) is identical within error limits to the widely used E. huxleyi calibrations of and attesting their general applicability. The observation that core-top calibrations extending over various biogeographical coccolithophorid zones are strongly linear and in better accordance than culture calibrations suggests that U37K' is less species-dependent than is indicated by culture experiments. The results also suggest that variations in growth rate of algae and nutrient availability do not significantly affect the sedimentary record of U37K' in open ocean environments.

Supplement to: Müller, Peter J; Kirst, Georg; Ruhland, Götz; Von Storch, Isabel; Rosell-Melé, Antoni (1998): Calibration of the alkenone paleotemperature index UK'37 based on core-tops from the eastern South Atlantic and the global ocean (60°N-60°S). Geochimica et Cosmochimica Acta, 62(10), 1757-1772

Identifier
DOI https://doi.org/10.1594/PANGAEA.54788
Related Identifier https://doi.org/10.1016/S0016-7037(98)00097-0
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.54788
Provenance
Creator Müller, Peter J; Kirst, Georg; Ruhland, Götz; Von Storch, Isabel; Rosell-Melé, Antoni ORCID logo
Publisher PANGAEA
Publication Year 1998
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 447 data points
Discipline Geosciences; Natural Sciences
Spatial Coverage (-18.690W, -55.470S, 17.760E, 1.800N); Walvis Ridge; Guinea Basin; Equatorial Atlantic; Brazil Basin; Romanche fracture zone; Cape Basin; Kongo delta; Northern Guinea Basin; Southwest Guinea Basin; West Angola Basin; Mid Atlantic Ridge; East Brazil Basin; Congo Fan; off Kunene; Namibia Continental Margin; South African margin; Angola Diapir Field; Angola Benguela Front; Southern Cape Basin; Northern Cape Basin; Van Heesen Ridge; Agulhas Basin; Meteor Rise; Shona Ridge; Indian-Antarctic Ridge; Atlantic Ridge; South Sandwich Basin; Agulhas Ridge; South Atlantic
Temporal Coverage Begin 1988-02-20T00:00:00Z
Temporal Coverage End 1996-01-16T00:00:00Z