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| Titel |
Hydrographic oscillations in the northeastern Arabian Sea during the past 80 ka |
| VerfasserIn |
Andreas Lueckge, Gaudenz Deplazes, Georg Scheeder, Gerald Haug  , Jürgen Pätzold |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250050614
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| Zusammenfassung |
| Paleoclimatic studies have shown that abrupt changes in monsoon intensity in the Arabian
Sea are correlated to the Dansgaard/Oeschger (DO) and Heinrich events known from
Greenland ice cores and marine sediment cores. However, the extent, timing and modes of
interaction with high-latitude climate are still under debate. To explore this issue, we present
a high-resolution paleoceanographic reconstruction for the past 80,000 years from sediment
core SO130-289KL (23Ë 07.34´N, 66Ë 29.84´E), which was retrieved off the Pakistan coast.
Interstadials (DO events and the Holocene section) are characterized by laminated
sediments enriched in organic carbon (up to 4 % TOC) whereas bioturbated sediments
with low TOC contents (< 1 % TOC) appear during stadials. The stable oxygen
isotopes of the surface-dwelling planktonic foraminifer G. ruber (white s.s.) and the
thermocline dweller P. obliquiloculata show a strong correspondence to Greenland ice
core temperature records. The deepwater stable oxygen isotope signal of benthic
foraminifera (U. peregrina and G. affinis) primarily reflects patterns recorded in
temperature reconstructions in ice cores from Antarctica. Vertical δ18O gradients are more
pronounced during DO events, suggesting stronger water-column stratification.
Alkenone-derived sea-surface temperatures varying between 25 and 28Ë C follow the benthic
oxygen isotope record suggesting a strong seasonal component of the Uk37 signal.
The detailed paleoceanographic reconstruction of hydrographic conditions in the
northeastern Arabian Sea implies a close atmospheric teleconnection to high northern
latitudes as well as a water mass conversion originating in the southern hemisphere. |
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