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| Titel |
Southern ocean warming, sea level and hydrological change during the Paleocene-Eocene thermal maximum |
| VerfasserIn |
A. Sluijs, P. K. Bijl, S. Schouten, U. Röhl, G.-J. Reichart, H. Brinkhuis |
| 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. 1 ; Nr. 7, no. 1 (2011-01-26), S.47-61 |
| Datensatznummer |
250004395
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| Publikation (Nr.) |
 copernicus.org/cp-7-47-2011.pdf |
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| Zusammenfassung |
| A brief (~150 kyr) period of widespread global average surface warming
marks the transition between the Paleocene and Eocene epochs, ~56
million years ago. This so-called "Paleocene-Eocene thermal maximum" (PETM)
is associated with the massive injection of 13C-depleted carbon,
reflected in a negative carbon isotope excursion (CIE). Biotic responses
include a global abundance peak (acme) of the subtropical dinoflagellate
Apectodinium. Here we identify the PETM in a marine sedimentary sequence deposited on
the East Tasman Plateau at Ocean Drilling Program (ODP) Site 1172 and show,
based on the organic paleothermometer TEX86, that southwest Pacific sea
surface temperatures increased from ~26 °C to ~33°C
during the PETM. Such temperatures before, during and after the PETM are
>10 °C warmer than predicted by paleoclimate model simulations for this
latitude. In part, this discrepancy may be explained by potential seasonal
biases in the TEX86 proxy in polar oceans. Additionally, the data
suggest that not only Arctic, but also Antarctic temperatures may be
underestimated in simulations of ancient greenhouse climates by current
generation fully coupled climate models. An early influx of abundant
Apectodinium confirms that environmental change preceded the CIE on a global scale.
Organic dinoflagellate cyst assemblages suggest a local decrease in the
amount of river run off reaching the core site during the PETM, possibly in
concert with eustatic rise. Moreover, the assemblages suggest changes in
seasonality of the regional hydrological system and storm activity. Finally,
significant variation in dinoflagellate cyst assemblages during the PETM
indicates that southwest Pacific climates varied significantly over time
scales of 103 – 104 years during this event, a finding comparable
to similar studies of PETM successions from the New Jersey Shelf. |
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