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| Titel |
Quantifying sea surface temperature ranges of the Arabian Sea for the past 20 000 years |
| VerfasserIn |
G. M. Ganssen, F. J. C. Peeters, B. Metcalfe, P. Anand, S. J. A. Jung, D. Kroon, G.-J. A. Brummer |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 7, no. 4 ; Nr. 7, no. 4 (2011-12-08), S.1337-1349 |
| Datensatznummer |
250004691
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| Publikation (Nr.) |
 copernicus.org/cp-7-1337-2011.pdf |
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| Zusammenfassung |
| The oxygen isotopic composition of planktonic foraminifera tests is
one of the widest used geochemical tools to reconstruct past changes of
physical parameters of the upper ocean. It is common practice to analyze
multiple individuals from a mono-specific population and assume that the
outcome reflects a mean value of the environmental conditions during
calcification of the analyzed individuals. Here we present the oxygen
isotope composition of individual specimens of the surface-dwelling species
Globigerinoides ruber and
Globigerina bulloides from sediment cores in the
Western Arabian Sea off Somalia, inferred as
indicators of past seasonal ranges in
temperature. Combining the δ18O measurements of
individual specimens to obtain temperature ranges with Mg/Ca based mean
calcification temperatures allows us to reconstruct temperature extrema. Our
results indicate that over the past 20 kyr the seasonal temperature range
has fluctuated from its present value of 16 °C to mean values
of 13 °C and 11 °C for the Holocene and LGM,
respectively. The data for the LGM suggest that the maximum temperature was
lower, whilst minimum temperature remained approximately constant.
The rather minor variability in lowest summer temperatures during
the LGM suggests roughly constant summer monsoon intensity, while upwelling-induced productivity was lowered. |
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