Pan-Hemispheric bi-partition of the Younger Dryas Stadial inferred from a multi-proxy study of the Lake Suigetsu sediments, Japan
Abstract
The Younger Dryas Stadial (YDS) is a well studied, but not yet fully understood feature of the Last Glacial Interglacial Transition (LGIT). The YDS marks a northern hemispheric cooling, which occurred roughly between 12.8 and 11.6 ka BP and is associated with a weakening of the Atlantic Meridional Overturning Circulation (AMOC). From European and North Atlantic records it is known that the YDS has a bipartite structure. After 12.3 ka BP the AMOC regained some of its strength, resulting in the northward shift of the polar front and the westerlies, resulting in slightly warmer conditions in the second phase of the YDS. We present multiproxy data (microfacies, pollen, µXRF, stable isotope) from Lake Suigetsu (Japan) in which we found a contemporaneous bi-partition of the YDS interval. This is the first time that the bi-partition has been observed outside the North Atlantic region, showing that the two phase character was not regionally limited but a pan-hemispheric phenomenon. In contrast to European records our data show a cooler rather than a warmer second phase of the YDS, implying a climatic dipole between the North Atlantic and East Asia. We suggest that changes in moisture transport into Asia as a result of increased North Atlantic sea surface temperatures and displaced westerlies altered the atmospheric circulation in (East) Asia, producing the northern hemispheric climatic dipole pattern.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMPP41D..06S
- Keywords:
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- 1051 Sedimentary geochemistry;
- GEOCHEMISTRYDE: 1165 Sedimentary geochronology;
- GEOCHRONOLOGYDE: 1520 Magnetostratigraphy;
- GEOMAGNETISM AND PALEOMAGNETISMDE: 1890 Wetlands;
- HYDROLOGY