14C and 10Be around 1650 cal BC: are there contradictions between tree ring and ice core time scales?

Abstract

There is a debate about the date of the Minoan eruption of Santorini as reconstructed from a branch of an olive tree that was buried alive in trephra on Santorini2 and the dating of an ice core horizon attributed to this eruption.3 The olive branch was 14C-wiggle matched to the 14C calibration curve and yielded an age range of 1627-1600 bc4 while the counting of annual layers in the Greenland ice cores produced an age of 1642 (±5) bc.5 Here I will study the relative timing of the two time scales by comparing the cosmic ray signal as recorded by 14C in tree rings and 10Be in ice cores. The result reveals an intriguing age difference that is similar to the dating difference mentioned above. The origin of the difference is unclear. This analysis supports both the dating of the Santorini eruption with the olive branch and the identification of this eruption in the ice cores, but it suggests unrecognised uncertainties in the tree ring 14C data, the ice core chronology or both.