Olive shrub buried on Therasia supports a mid-16th century BCE date for the Thera eruption

Abstract

The precise date of the 2nd millennium BCE (“Minoan”) eruption of Thera (Santorini) has long been a focus of controversy due to a discrepancy between archaeological and radiocarbon-based dating of materials from stratigraphic layers above and below tsunami, ash and pumice deposits resulting from the eruption. A critical, though controversial, piece of evidence has been four segments of a radiocarbon-dated olive tree branch, buried on Thera during the eruption. Here we report new radiocarbon evidence from an olive shrub found carbonized by the same eruption deposits on neighboring Therasia (Santorini). The Therasia olive shrub dates slightly younger than the previous olive branch. Calibrated results and growth increment counts indicate increased probabilities for a mid-16th century BCE date for the eruption, overlapping with multiple volcanic sulfate markers from ice core records.

Volcanic glass from the 1.8 ka Taupō eruption (New Zealand) detected in Antarctic ice at ~ 230 CE

“…Holdaway et al 35 , 36 instead asserted that the Taupō eruption occurred at an unknown date, decades to two centuries later, bringing into question the use of the Taupō Tephra as a reliable time-stratigraphic marker. Their proposal has significant implications for both the timing of the Taupō eruption and also for other proximally-dated, unobserved, eruptions such as the Minoan eruption of Thera 59 (Santorini) and the 1314 ± 12 CE (2 SD) Kaharoa eruption 60 (New Zealand).…”

Sub-annual bomb radiocarbon records from trees in northern Israel

“…An offset of about 2.5 ‰ for plant materials growing in the northern hemisphere but in season opposite to that of central and northern Europe and North American trees has been observed 57 , 58 . A similar offset can be expected in olive wood 14 C records from pre-bomb periods, and it can significantly influence calibrated age of events dated using olive wood radiocarbon dates, such as the Minoan eruption event of Santorini 59 , 60 . The Minoan volcanic event of Santorini is an important time marker in the archaeological records of the eastern Mediterranean region, however, the date of this event is still under scientific discussion.…”

“…Applying an offset of 2.5 ‰ calibration model of Santorini olive wood 14 C dates can clearly increase the probability for younger event dates, mostly in the sixteenth century BCE (Figure S7). Pearson et al 60 had also shown that model results with an offset of 13.7 ± 2 14 C years increased the probabilities of the sixteenth century BCE date for the Minoan eruption event. However, with current understanding, it is difficult to ascertain if these olive wood 14 C dates had the offset arising from a shift in the growing season.…”