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| Titel |
On the evolution of Mediterranean Sea Water during climate warm stages (MIS 1, 5, 7) |
| VerfasserIn |
Jean-Carlos Montero-Serrano, Norbert Frank, Christophe Colin |
| 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 |
250054885
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| Zusammenfassung |
| The Nd isotopic composition of the aragonite skeleton of fossil reef framework forming
cold-water corals provides a way to reconstruct the provenance of water masses bathing the
reefs (e.g., Copard et al., 2010; van de Flierdt et al., 2010; Colin et al., 2010). Here, we have
reconstructed the Nd-isotopic composition of corals on two sites along the eastern
north Atlantic, the Gulf of Cadiz (off Morocco) to the south and the Porcupine
Seabight (Belgica Mound Province) to the north. A stunting evolution of the northward
propagation of Mediterranean Sea Water (MSW) came to light for the past three
climate warm stages (Marine Isotope Stages –MIS– 1, 5, 7). In fact, water masses
in the Gulf of Cadiz reveal rather constant Nd-isotopic composition (ÉNd ~ -9
to -11) during climate warm stages similar to present day MSW (ÉNd ~ -9.4 to
-11). In contrast, corals from Porcupine Seabight reveal dramatic changes over the
past three climatic warm stages. During stage MIS 7 the isotopic composition of
water masses in Porcupine Seabight is identical to the one of the Gulf of Cadiz,
most likely reflecting a strong northward export of MSW. In contrast, during MIS
5 and 1 a large contrast between southern (ÉNd ~ -9 to -11) and northern reefs
is found (ΔÉND = -3 to -4) indicating largely reduced northward flow of MSW
compared to MIS 7. This difference is likely related to a far stronger eastward export
of intermediate water from the subpolar gyre during the past two climatic warm
stages.
References:
Copard et al., 2010. Quaternary Science Reviews 29: 2499-2508.
Colin et al., 2010. Quaternary Science Reviews 29: 2509-2517.
van de Flierdt et al., 2010. Geochimica et Cosmochimica Acta 74: 6014-6032. |
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