Darmstadt 2008 – wissenschaftliches Programm
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SYER: Symposium Trace species in environmental research
SYER 1: Session I
SYER 1.2: Hauptvortrag
Mittwoch, 12. März 2008, 12:30–13:00, 3C
Changes in ocean meridional overturning circulation over glacial termination I – The global record of marine C-14 paleoreservoir ages 23 - 13 cal. ka — •Michael Sarnthein1, Pieter M. Grootes1, Ann Holbourn1, James P. Kennett2, and Marie-J. Nadeau1 — 1Universität Kiel, D-24098 Kiel, Germany — 2University of California Santa Barbara, Santa Barbara, California 93106, USA
Dramatic climate changes occurred during early last deglacial times, 19.0-14.5 cal. ka. They were linked to most fundamental recent changes in ocean circulation, which likely contributed to major shifts in CO2 transfer from ocean to atmosphere. Marine radiocarbon (C-14) paleoreservoir ages provide unique new insights into the fate of paleo-water masses associated with changes in meridional overturning circulation (MOC). These ages are monitored at an ever growing number of key locations in all three oceans by means of a new C-14 plateau tuning technique. Opposite trends in paleoreservoir ages indicate a short-lasting phase of deep and intermediate-water formation in the North Pacific 17.5 to less than 14.6 cal. ka. This event was coeval with a brief northward reversal of Denmark Strait Overflow waters in the North Atlantic, the source region of modern global MOC, and a dramatic cooling of North Atlantic and Eurasian climate (Heinrich-1 event).