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| Titel |
Antarctic ice sheet and oceanographic response to eccentricity forcing during the early Miocene |
| VerfasserIn |
D. Liebrand, L. J. Lourens, D. A. Hodell, B. Boer, R. S. W. Wal, H. Pälike |
| 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. 3 ; Nr. 7, no. 3 (2011-08-12), S.869-880 |
| Datensatznummer |
250004615
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| Publikation (Nr.) |
 copernicus.org/cp-7-869-2011.pdf |
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| Zusammenfassung |
| Stable isotope records of benthic foraminifera from ODP Site 1264 in the
southeastern Atlantic Ocean are presented which resolve the latest Oligocene
to early Miocene (~24–19 Ma) climate changes at high temporal
resolution (<3 kyr). Using an inverse modelling technique, we decomposed
the oxygen isotope record into temperature and ice volume and found that the
Antarctic ice sheet expanded episodically during the declining phase of the
long-term (~400 kyr) eccentricity cycle and subsequent low short-term
(~100 kyr) eccentricity cycle. The largest glaciations are separated by
multiple long-term eccentricity cycles, indicating the involvement of a
non-linear response mechanism. Our modelling results suggest that during the
largest (Mi-1) event, Antarctic ice sheet volume expanded up to its
present-day configuration. In addition, we found that distinct ~100 kyr
variability occurs during the termination phases of the major Antarctic
glaciations, suggesting that climate and ice-sheet response was more
susceptible to short-term eccentricity forcing at these times. During two of
these termination-phases, δ18O bottom water gradients in the
Atlantic ceased to exist, indicating a direct link between global climate,
enhanced ice-sheet instability and major oceanographic reorganisations. |
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