Timing of the onset of MIS11 revealed by speleothem in southern Europe
Résumé
The interglacial period, known as Marine Isotope Stage 11 (MIS 11, 428-397 thousand years ago), is often considered
as a potential analogue for future climate projection because of the similar patterns of insolation variability.
However, studies on mechanisms of the onset of MIS 11 (called Termination V, T-V) in response to insolation
increase is still hampered by a lack of good dating materials in paleoclimate archives, despite a stack of East Asian
monsoon records with precise U-Th dates has been proposed. Previous studies suggested the 18O value registered
in speleothems in Mediterranean realm can be a good bridge connecting the U-Th-based age model of speleothem
to marine cores from Mediterranean sea, which opens a new possibility to detect ocean-atmosphere/internalexternal
forcing interaction beyond 14C dating limitation. Here we present a new speleothem 18O record from
northern Italy covering 500-300 thousand years ago. The results show a similar pattern with 18O records of
marine cores around Mediterranean. The age model of the speleothem hence provides an opportunity for tuning
the marine cores, which could improve our understanding of relationship between global atmosphere and ocean
circulations.