Carbon consists of 99% carbon-12, 1% carbon-13, and about one part per million carbon-14.
Results of carbon-14 dating are reported in radiocarbon years, and calibration is needed to convert radiocarbon years into calendar years.
It should be noted that a BP notation is also used in other dating techniques but is defined differently, as in the case of thermoluminescence dating wherein BP is defined as AD 1980.
It is also worth noting that the half-life used in carbon dating calculations is 5568 years, the value worked out by chemist Willard Libby, and not the more accurate value of 5730 years, which is known as the Cambridge half-life.
Calibration of radiocarbon results is needed to account for changes in the atmospheric concentration of carbon-14 over time.
These changes were brought about by several factors including, but not limited to, fluctuations in the earth’s geomagnetic moment, fossil fuel burning, and nuclear testing.
Various techniques are used to CROSSDATE wood samples to assure accurate dating.
A key distinction of dendrochronology is that all trees rings being analyzed are dated to their correct year of formation.
At present, tree rings are still used to calibrate radiocarbon determinations.
Libraries of tree rings of different calendar ages are now available to provide records extending back over the last 11,000 years.
The practical applications of the study of tree rings are numerous.
Dendrochronology is an interdisciplinary science, and its theory and techniques can be applied to many applications. These research interests have in common the following objectives: Ring-counting does not ensure the accurate dating of each individual ring.