We have seen remarkable advances in our understanding of the Earth’s systems, as well as the proliferation of high quality radiocarbon calibration data, since the publication of the first calibration curves constructed by the IntCal Working Group in 2004. In this issue we present the 2020 Northern and Southern Hemisphere terrestrial and marine calibration curves (Reimer et al. 2020; Hogg et al. 2020; Heaton et al. 2020b), as well as a new, custom-designed Bayesian statistical method for curve construction (Heaton et al. 2020a).
In addition the reader will find papers detailing a tree-ring radiocarbon inter-comparison exercise (Wacker et al. 2020), a discussion of the strengths and weaknesses of the selected tree-ring data (Bayliss et al. 2020) and a number of papers presenting new data for single year tree-ring measurements for the Holocene (Fahrni et al. 2020; Friedrich et al. 2020; Kudsk et al. 2019; Kuitems et al. 2020; Pearson et al. 2020). A dendrochronological extension and 14C measurements of the Late Glacial European Preboreal Pine chronology is presented by Reinig et al. (2020) and Sookdeo et al. (2019). Dendrochronology and 14C measurements of Late Glacial floating tree-rings from the Alps are given by Capano et al. (2019). Updates to the timescales for the Lake Suigetsu varved and the Cariaco basin sedimentrecords are described in Bronk Ramsey et al. (2020) and Hughen & Heaton (2020). The Marine Reservoir Ages calculated with an ocean general circulation model for each region with marine data used in IntCal20 is given by Butzin et al. (2020).
A comparison of the IntCal20 curve with independently dated events as well as a transfer function for converting between the IntCal20 timescale (primarily based on U-Th dates for the older portion of the curve) and the Greenland Ice Core Chronology (GICC05) is presented in Muscheler et al. (2020). The effect of the IntCal20 curve on some important examples of previously published radiocarbon ages is highlighted in van der Plicht et al. (2020).
This is the seventh radiocarbon calibration issue that I’ve had the pleasure of seeing come together under the lead of either Minze Stuiver or myself. I have had a great experience working with an amazing group of people to produce this latest update to the radiocarbon calibration curves. I am confident that the IntCal Working Group will continue to work together to provide the user community with ever improving calibration curves under the capable leadership of Christopher Bronk Ramsey.
