‘Ats us nai’—adaptive sampling strategies for the radiocarbon wiggle-match dating of trees

Wiggle-match dating is an approach to obtaining very precise age estimates for 'floating' trees by combining multiple radiocarbon-dated annual rings with the known relative dating information contained within the tree's rings. Whereas individual radiocarbon dates often have multi-decadal to centennial uncertainties, wiggle-match dating can result in annual precision of both a tree's felling age and the ages of all other rings. Here, we develop a numerical sampling strategy, with the aim of helping researchers decide which rings to date in order to obtain annual precision with as few radiocarbon dates as possible so that they can say, 'ats us nai' ('that's us now' or 'we're done'). The sampling score is tested on a real-world case study as well as on simulated trees. The latter are used to investigate the effect of dating scatter, a tree's timespan and its felling age on both the precision and accuracy of the felling age estimates. The results are used to provide advice for future studies that aim to use wiggle-match dating to place trees on a secure calendar scale. This article is part of the Theo Murphy meeting issue 'Radiocarbon and cosmic radiation events'.