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Titel |
Pulses of enhanced North Pacific Intermediate Water ventilation from the Okhotsk Sea and Bering Sea during the last deglaciation |
VerfasserIn |
L. Max, L. Lembke-Jene, J.-R. Riethdorf, R. Tiedemann, D. Nürnberg, H. Kühn, A. Mackensen |
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 ; 10, no. 2 ; Nr. 10, no. 2 (2014-03-21), S.591-605 |
Datensatznummer |
250116940
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Publikation (Nr.) |
copernicus.org/cp-10-591-2014.pdf |
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Zusammenfassung |
Under modern conditions only North Pacific Intermediate Water is formed in
the northwest Pacific Ocean. This situation might have changed in the past.
Recent studies with general circulation models indicate a switch to
deep-water formation in the northwest Pacific during Heinrich Stadial 1
(17.5–15.0 ka) of the last glacial termination. Reconstructions of past
ventilation changes based on paleoceanographic proxy records are still
insufficient to test whether a deglacial mode of deep-water formation in the
North Pacific Ocean existed. Here we present deglacial ventilation records
based on radiocarbon-derived ventilation ages in combination with epibenthic
stable carbon isotopes from the northwest Pacific including the Okhotsk Sea
and Bering Sea, the two potential source regions for past North Pacific
ventilation changes. Evidence for most rigorous ventilation of the
intermediate-depth North Pacific occurred during Heinrich Stadial 1 and the
Younger Dryas, simultaneous to significant reductions in Atlantic Meridional
Overturning Circulation. Concurrent changes in δ13C and
ventilation ages point to the Okhotsk Sea as driver of millennial-scale
changes in North Pacific Intermediate Water ventilation during the last
deglaciation. Our records additionally indicate that changes in the
δ13C intermediate-water (700–1750 m water depth) signature and
radiocarbon-derived ventilation ages are in antiphase to those of the deep
North Pacific Ocean (>2100 m water depth) during the last
glacial termination. Thus, intermediate- and deep-water masses of the
northwest Pacific have a differing ventilation history during the last deglaciation. |
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