HR: 1340h
AN: U43A-0737    [Abstracts]
TI: Atmospheric radiocarbon fluctuations in the Late Glacial obtained from tree-ring chronologies - aspects of rapid climate change
AU: * Talamo, S
EM: sahra.talamo@iup.uni-heidelberg.de
AF: Heidelberg Academy of Sciences, INF 229, Heidelberg, 69120 Germany
AU: Kromer, B
EM: Bernd.Kromer@iup.uni-heidelberg.de
AF: Heidelberg Academy of Sciences, INF 229, Heidelberg, 69120 Germany
AU: Friedrich, M
EM: michaelf@uni-hohenheim.de
AF: University of Hohenheim, Institute of Botany-210, Stuttgart, 70593 Germany
AU: Remmele, S
EM: remmeles@uni-hohenheim.de
AF: University of Hohenheim, Institute of Botany-210, Stuttgart, 70593 Germany
AU: Kaiser, F
EM: kaiser@wsl.ch
AF: Swiss Federal Reserch Institute WSL, Zrcherstrasse 111, Birmensdorf, 8903 Switzerland
AU: Kaiser, F
EM: kaiser@wsl.ch
AF: University of Zurich, Geography Dept., Zurich, 8057 Switzerland
AU: Schaub, M
EM: matthias.schaub@wsl.ch
AF: Swiss Federal Reserch Institute WSL, Zrcherstrasse 111, Birmensdorf, 8903 Switzerland
AB: We built a floating 1382-ring chronology based on pines recovered from alluvial deposits in Germany, Switzerland and Northern Italy. It includes a tree buried in situ by the Laacher See eruption (LSE) providing already a strong constraint about the absolute age of the chronology. We performed high-precision 14C (+-25 years) analyses of decadal resolution samples. The end of the chronology covers the initial 150 years of the Younger Dryas (YD) as evidenced by the strong 14C age drop from 10,950 14C BP to 10,680 BP in less than 50 years, commonly considered marking the onset of YD. Based on these constraints we can calculate the approximate atmospheric 14C level during the Bolling/Allerod interval. We observe several substantial 14C fluctuations that appear synchronous to cooling events documented in Greenland ice cores and the Cariaco basin sediments, among others. In the contribution potential causes of atmospheric 14C fluctuations (solar activity changes, ocean ventilation change, sea ice cover) are discussed and their relation to rapid climate change in the LG and early YD is considered.
UR: http://www.iup.uni-heidelberg.de/institut/forschung/groups/fa/radiokohlenstoff/radiometrie-web-html
DE: 3344 Paleoclimatology
DE: 4221 Dendrochronology
DE: 1035 Geochronology
DE: 1620 Climate dynamics (3309)
DE: 1650 Solar variability
SC: Union [U]
MN: 2004 AGU Fall Meeting