Blocks of the same tree rings were previously used to generate IntCal calibration data. The new data set has an offset to the IntCal13 calibration data of 24 years and is similar to the annual data for the same period derived from tree ring records at other growing sites.
A subset of samples from the period 1625-1585 BC was additionally measured in three other laboratories (ETH, AAR, AA) for quality control purposes.
Details: www.cambridge.org:
www.cambridge.org/core/journals/radiocarbon/article/abs/new-annual-14c-dataset-for-calibrating-the-thera-eruption/174B2E32FC47F1AEAE9BF2B9363CD7A8