Radiocarbon dating is a technique commonly used by scientists and archaeologists to establish the ages and times since death for ancient human remains. It is very precise and accurate and is therefore used for a range of biological specimens as well (Mason, 2017).
An American scientist called Willard Frank Libby first perceived the basis of a dating method supported by the prediction of the existence …show more content…
This case study displays how the process of radiocarbon dating is applied in a real-life situation. On 19 September 1991, two mountain hikers discovered this amazing specimen in a shallow, ice filled depression at 3,210 meters on a mountain ridge of the Ötztal Alps, forming the border between Austria and Italy. His body was naturally mummified and entombed in the shallow glacier. Initially, no one suspected that the body was prehistoric, and it was thought that it might have been a mountain hiker who had been caught in a glacier, as the body did not show that extent of decomposition (Kutschera & Rom, 2000). The time since death estimations, in this case, helped establish archaeological relevance, however, basing this estimation on decomposition would not have worked and radiocarbon dating gave more precise results. This is because the rate at which a cadaver (dead body) decomposes, is dependent upon several variables, such as; temperature, access by insects, humidity/aridity and rainfall, etc. (Mann, et al., 1990). Cold environments, like the one in which Ötzi was found, inhibit the growth and action of microorganisms and due to the extremely low temperature, the decay process is greatly reduced (Cantor, …show more content…
The age (t) was determined from the exponential decrease in the carbon isotope ratio: (14C/12C)t = (14C/12C)t=0 e-λt, by measuring the present-day ratio (14C/12C)t, where λ is a constant equal to the reciprocal of the mean life (Bowman, 1990). As calculation of age requires knowing the initial ratio and since this ratio was not constant in time, detailed calibration procedures were implemented. Measurements of radiocarbon content in tree rings of known age, obtained from dendrochronological (the study of annual rings of trees to determine dates and chronological order of past events) work were used to extend the calibration back to about 12,000 years. The measured ratio was then used to calculate the uncalibrated age, an internationally accepted reference value was used for the (14C/12C)t ratio. The radiocarbon age is a fixed value and is different from the true calendar age, which can be obtained using the calibration curve that is continuously updated and extended towards the radiocarbon dating limit. Radiocarbon measurements of bone and tissue from Ötzi along with the grass found with him, were first carried out at the AMS (accelerator mass spectrometry) facilities in Zurich and Oxford. The combined uncalibrated radiocarbon age was found to be 4546 ± 17 years BP (before present = 1950), however some of the data displayed that the calibration shifts the age by almost