Carbon dating calibration calculator
Tree rings provided truly known-age material needed to check the accuracy of the carbon-14 dating method.
At present, tree rings are still used to calibrate radiocarbon determinations.If a sample has the same proportion of radiocarbon as that of the tree ring, it is safe to conclude that they are of the same age.In practice, tree-ring calibration is not as straightforward due to many factors, the most significant of which is that individual measurements made on the tree rings and the sample have limited precision so a range of possible calendar years is obtained.Suess’s curve, based on the bristlecone pine, used tree rings for its calendar axis.There have been many calibration curves published since Suess’s curve, but their proliferation brought more problems than solutions.It is also called “radiocarbon” because it is unstable and radioactive relative to carbon-12 and carbon-13.
Carbon consists of 99% carbon-12, 1% carbon-13, and about one part per million carbon-14.
Radiocarbon dating laboratories have been known to use data from other species of trees.
In principle, the age of a certain carbonaceous sample can be easily determined by comparing its radiocarbon content to that of a tree ring with a known calendar age.
For the period after 1950, a great deal of data on atmospheric radiocarbon concentration is available.
Post-modern data are very useful in some cases in illustrating a calendar age of very young materials (Hua, et. Atmospheric Radiocarbon for the period 1950-2010, Radiocarbon, 55(4), 2013).
In later years, the use of accelerator mass spectrometers and the introduction of high-precision carbon dating have also generated calibration curves.