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| Titel |
Tree ring and ice core time scales around the Santorini eruption |
| VerfasserIn |
Elin Löfroth, Raimund Muscheler, Ala Aldahan, Göran Possnert, Ann-Marie Berggren |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250042614
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| Zusammenfassung |
| When studying cosmogenic radionuclides in ice core and tree ring archives around the
Santorini eruption a ~20 year discrepancy was found between the records (Muscheler 2009).
In this study a new 10Be dataset from the NGRIP ice core is presented. It has a resolution of
7 years and spans the period 3752-3244 BP (1803-1295 BC). The NGRIP 10Be
record and the previously published 10Be GRIP record were compared to the IntCal
datasets to further investigate the discrepancy between the ice core and tree ring
chronologies. By modelling the 14C production rate based on atmospheric 14C records a
comparison could be made to the 10Be flux which is assumed to represent the 10Be
production rate. This showed a time shift of ~23 years between the records. The
sensitivity of the results to changes in important model parameters was evaluated.
Uncertainties in the carbon cycle model cannot explain a substantial part of the timing
differences.
Potential influences of climate and atmospheric processes on the 10Be deposition were
studied using δ18O from the respective cores and GISP2 ice core ion data. The comparison to
δ18O revealed a small but significant correlation between 10Be flux and δ18O when the
14C-derived production signal was removed from the 10Be curves. The ion data, as proxies
for atmospheric circulation changes, did not show any correlations to the 10Be record or the
10Be/14C difference.
When including possible data uncertainties there is still a minimum discrepancy of ~10
years between the 10Be ice core and the 14C tree ring record. Due to lack of alternative
explanations it is concluded that the ice core and/or the tree ring chronologies contains
unaccounted errors in this range. This also reconciles the radiocarbon 1627-1600 BC
(Friedrich et al., 2006) and ice core 1642±5 BC (Vinther et al., 2006) datings of the Santorini
eruption.
Friedrich, W.L., Kromer, B., Friedrich, M., Heinemeier, J., Pfeiffer, T., & Talamo, S.,
2006: Santorini eruption radiocarbon dated to 1627-1600 BC. Science 312, 548-548.
Muscheler, 2009: 14C and 10Be around 1650 cal BC. In Warburton, D.A., (ed.): Time’s
Up! Dating the Minoan Eruption of Santorini: acts of the Minoan Eruption Chronology
Workshop, Sandbjerg November 2007: Monographs of the Danish Institute at Athens. Aarhus
University Press, Aarhus. 298 pp.
 Vinther, B.M., Clausen, H.B., Johnsen, S.J., Rasmussen, S.O., Andersen, K.K.,
Buchardt, S.L., Dahl-Jensen, D., Seierstad, I.K., Siggaard-Andersen, M.L., Steffensen, J.P.,
Svensson, A., Olsen, J., & Heinemeier, J., 2006: A synchronized dating of three Greenland
ice cores throughout the Holocene. Journal of Geophysical Research-Atmospheres 111, 11. |
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