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| Titel |
Persistent linkage between long-term eccentricity cycles in Antarctic ice volume and changes in the global carbon cycle during the Pliocene and Pleistocene |
| VerfasserIn |
Bas De Boer, Lucas Lourens, Roderik van de Wal |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250080573
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| Zusammenfassung |
| The imprint of the 400,000 and 100,000 year cycles on high-resolution deep sea carbon
(δ13C) and oxygen (δ18O) records have been found in the Oligocene to Middle Miocene time
interval, when global climate change was under the influence of the waxing and waning of
Antarctic ice sheet. In contrast, the long-eccentricity signal is absent in the Pleistocene
ice-age records, while oceanic carbon isotope records do reveal long-term changes in the
global carbon reservoir. Here we have simulated global ice volume over the past 5 million
years (Myr) using a coupled system of four 3-D ice-sheet-shelf models, comprising the
glaciations on Eurasia, North America, Greenland and Antarctica, thereby explicitly
calculating all ice-volume contributions. With an inverse approach ice volume and
temperature are derived from the global mean LR04 benthic δ18O record. Although
the LR04 stack does not reflect a strong signal in the 400-kyr long-eccentricity
cycles, the simulated Antarctic ice sheet reflects a strong 400-kyr signal throughout
the Plio-Pleistocene. Evidently, the long-term eccentricity bound changes in the
Antarctic ice sheet co-vary with the planktonic foraminifera δ13C record of the
Mediterranean over the past 5 Myr and with the benthic stacked δ13C record of ODP
Leg 154 (Ceara Rise) sites in the equatorial Atlantic between 5 and 1.5 Myr ago.
This suggests a persistent linkage between eccentricity-paced Antarctic ice sheet
fluctuations and changes in the carbon cycle throughout the late Cenozoic icehouse world. |
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