Publication Date:
2022-05-25
Description:
Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 20 (2005): PA3009, doi:10.1029/2004PA001091.
Description:
Similar orbital geometry and greenhouse gas concentrations during marine isotope stage 11 (MIS 11) and the Holocene make stage 11 perhaps the best geological analogue period for the natural development of the present interglacial climate. Results of a detailed study of core MD01-2443 from the Iberian margin suggest that sea surface conditions during stage 11 were not significantly different from those observed during the elapsed portion of the Holocene. Peak interglacial conditions during stage 11 lasted nearly 18 kyr, indicating a Holocene unperturbed by human activity might last an additional 6–7 kyr. A comparison of sea surface temperatures (SST) derived from planktonic foraminifera for all interglacial intervals of the last million years reveals that warm temperatures during peak interglacials MIS 1, 5e, and 11 were higher on the Iberian margin than during substage 7e and most of 9e. The SST results are supported by heavier δ18O values, particularly during 7e, indicating colder SSTs and a larger residual ice volume. Benthic δ13C results provide evidence of a strong influence of North Atlantic Deep Water at greater depths than present during MIS 11. The progressive ocean climate deterioration into the following glaciation is associated with an increase in local upwelling intensity, interspersed by periodic cold episodes due to ice-rafting events occurring in the North Atlantic.
Description:
This work was partially undertaken in association with the
‘‘POP Project,’’ EC grant EVK2-2000-00089. Funding for L.A. was
provided by the Portuguese Foundation for Science and Technology under
the fellowship contract SFRH/BPD/1588/2000 and by the Calouste Gulbenkian
Foundation, through a visiting fellowship to Woods Hole Oceanographic
Institution.
Keywords:
Stage 11
;
Interglacials
;
Planktonic foraminifera
;
Stable isotopes
;
Western Iberian margin
;
Eastern North Atlantic
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
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