Variations in tree-ring 14C for the younger dryas
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Date
2009-05-15
Journal Title
Journal ISSN
Volume Title
Publisher
GNS Science
Abstract
Of all millennial-scale paleoclimate reversals during the Last Glacial Cycle, the
Younger Dryas (YD), from ~13 to 11.6 cal kyr BP, has attracted the most attention
and controversy. The debate centres on understanding the physical mechanisms for
such an abrupt change in climate and radiocarbon, which are associated with small
changes in solar output and/or major changes in earth-system interactions dealing
with oceanic circulation and exchanges between the carbon reservoirs. The leads and
lags between climatic proxy records of the YD event are at the heart of such research.
Unfortunately, one of the problems is that there is no reliable, direct atmospheric 14C
record based on tree-ring chronology for the whole YD period, thus negating any
possibility of locking in the critical time marker of its initiation.
Here we present new high-precision, high-resolution radiocarbon measurements for
the early YD chronozone derived from 4 sub-fossil logs of Huon pine with clearly
defined annual tree rings. These logs were excavated from alluvial sediments along
Stanley River in north-western Tasmania, Australia. A floating 617-ring Huon pine
chronology has been constructed based on ring width and AMS radiocarbon
measurements. Our 14C record, covering an age range from 10,350 to 10,760 14C years
BP, has been linked to the European absolute tree-ring and floating Late Glacial Pine
chronologies, bridging the current gap in the European tree-ring 14C chronologies
during the early YD. A continuous and reliable atmospheric 14C record for the past 14
cal kyr BP is now available. This allows a more precise determination of the timing in
observed climatic and environmental parameters and allows for a critical evaluation of
mechanisms of atmospheric 14C variations for the YD.
Description
Keywords
Glaciers, Climates, Carbon 14, Isotope dating, Tree rings, Solar activity, Alluvial deposits, Tasmania, Pines, Conifers
Citation
Hua, Q., Barbetti, M., Fink, D., Levchenko, V. A., Zoppi, U., Smith, A. M., & Bertuch, F. (2009). Variations in tree-ring 14C for the younger dryas. Paper presented at the Past Climates meeting, Wellington New Zealand, May 15-17, 2009.