C04_P07

Improved calibration method for dating multiple tree-rings and its implication on the Santorini debate

Raj H¹, Regev L¹, Boaretto E¹

¹Dangoor Research Accelerator Mass Spectromerty (D-REAMS) Laboratory, Weizmann Institute of Science, Rehovot, Israel

The Minoan eruption of Santorini, Greece, is an important and probably most debated chronological marker in contexts of the Eastern Mediterranean region. Among various age estimates of this event, one based on wiggle-matching of ¹⁴C dates from an olive branch found in Santorini by Friedrich et al. (2006) has been widely discussed. Four ¹⁴C ages were reported from this olive branch, each corresponding to a group of rings identified by X-ray tomography. Calibrated age estimates based on wiggle-matching of these ¹⁴C ages have been changing with improvements in the radiocarbon calibration curve. Such changes are important as the debate on the timing of the Minoan eruption is still not settled. It is understood that the calibration curve plays a crucial role in defining the calendar age range corresponding to ¹⁴C age(s). Interannual ¹⁴C levels can change significantly in the calibration curve, and the average ¹⁴C age of multiple rings dated together cannot always be calibrated to the middle year. Therefore, a different approach should be taken to calibrate the average ¹⁴C age of the multiple tree rings. We propose that calibration using the moving average calibration curve is more appropriate in such a case. Here, we recalibrated the four ¹⁴C  ages reported for the above olive section on the moving average calibration curves. Considering the ring counts of the above olive section accurate, the resulting calendar age for the last ring ranges between 1608-1589 BCE (68.3% confidence) and 1616-1576 BCE (95.4% confidence) with a peak at ca. 1600 BCE.