Radio carbon dating calibration
But it makes the implicit assumption that the every radiocarbon date is equally likely.It is easy to demonstrate that this is not true by taking the calibration curve and for each calendar date, finding the probability of each radiocarbon age. The probabilities assigned for each radiocarbon age are then summed. By inspecting the calibration curve, it is obvious that peaks in summed probability coincide with plateaux in the radiocarbon calibration curve.Tree rings of known age are from ancient bristlecone pine trees from Nevada and California, from oak logs buried in peat bogs in Europe, from archeological sites, and from other sources.Many dates reported in the scientific and popular literature are uncorrected radiocarbon dates.Unfortunately, Nonlinear Processes in Geophysics is one of only two EGU journals that does not have an open peer-review process, so we cannot read what the reviewers made of this paper.In his essay, Keenan writes that 25 potential reviewers had to be approached before enough could be found who were prepared to review the paper. The traditional procedure is explained in the calib manual The probability distribution P(R) of the radiocarbon ages R around the radiocarbon age U is assumed normal with a standard deviation equal to the square root of the total sigma [combined error of radiocarbon date and calibration curve].There have been several versions of the calibration curve, beginning, I think, in 1986 with Stuiver and Kra (1986).
A correction is possible based upon dating of tree-rings of known age and from paired radiocarbon and uranium-series dates of corals.Doug Keenan’s long essay about the IPCC treatment of surface temperature trends that I discussed earlier had a digression into his work on the calibration of radiocarbon dates that he published in 2012 in the open access EGU journal Nonlinear Processes in Geophysics.This caught my attention as I have a research interest in radiocarbon dating and constructing age-depth models.The Holocene part of the calibration curve is derived from radiocarbon analyses of tree-rings of known age.Corals and other materials are used for the late-Pleistocene section.