|
Detailed Reference Information |
N\"{a}gler, T.F., Eisenhauer, A., M\"{u}ller, A., Hemleben, C. and Kramers, J. (2000). The \delta$^{44}$Ca-temperature calibration on fossil and cultured \textit{Globigerinoides sacculifer}: New tool for reconstruction of past sea surface temperatures. Geochemistry Geophysics Geosystems 1. doi: 10.1029/2000GC000091. issn: 1525-2027. |
|
We report direct delta 44Ca-temperature calibration on cultured and fossil calcite foraminifera, showing that Ca isotopes are potentially a new proxy for past sea surface temperatures (SST). Samples have been analyzed using a 43Ca-48Ca double spike and techniques thermal ionization mass spectrometry (TIMS). In order to avoid species-dependent isotope fractionation we focused our investigations on a single foraminifera species (Globigerinoides sacculifer), which is known to inhabit shallow euphotic waters in tropical and subtropical oceans. Ca isotope measurements were performed on cultured G. sacculifer that grew in seawater kept at temperatures of 19.5?, 26.5?, and 29.5?C. A delta 44Ca change of 0.24 ? 0.02 per 1?C is defined by the weighted linear regression through reproduced delta 44Ca data of the three temperatures (95% confidence level). Application of this new method to fossil G. sacculifer of an Equatorial East Atlantic sediment core (GeoB1112; 5?46.7?S, 10?45.0?W, 3125 m) indicates that the delta 44Ca difference between marine isotope stage 1 (MIS-1) and MIS-2 is 0.71 ? 0.24. According to the current delta 44Ca-temperature calibration this difference corresponds to a temperature difference between MIS-1 and MIS-2 of 3.0 ? 1.0?C. |
|
|
|
BACKGROUND DATA FILES |
|
|
Abstract |
|
|
|
|
Entire Document PDF |
|
|
|
|
|
Keywords
Global Change, Climate dynamics, Oceanography, Biological and Chemical, Geochemistry, Oceanography, Biological and Chemical, Inorganic marine chemistry, Oceanography, Biological and Chemical, Trace elements |
|
Journal
Geochemistry Geophysics Geosystems |
|
Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
|
|
|