The remarkable metrological history of radiocarbon dating [II]

Abstract

This article traces the metrological history of radiocarbon, from the initial breakthrough devised by Libby, to minor (evolutionary) and major (revolutionary) advances that have brought 14C measurement from a crude, bulk [8 g carbon] dating tool, to a refined probe for dating tiny amounts of precious artifacts, and for “molecular dating” at the 10 µg to 100 µg level. The metrological advances led to opportunities and surprises, such as the non-monotonic dendrochronological calibration curve and the “bomb effect,” that gave rise to new multidisciplinary areas of application, ranging from archaeology and anthropology to cosmic ray physics to oceanography to apportionment of anthropogenic pollutants to the reconstruction of environmental history.Beyond the specific topic of natural 14C, it is hoped that this account may serve as a metaphor for young scientists, illustrating that just when a scientific discipline may appear to be approaching maturity, unanticipated metrological advances in their own chosen fields, and unanticipated anthropogenic or natural chemical events in the environment, can spawn new areas of research having exciting theoretical and practical implications.

Quantification of the carbonaceous matter origin in submicron marine aerosol by <sup>13</sup>C and <sup>14</sup>C isotope analysis

“…The carbon isotope 14 C is produced in the upper atmosphere and enters the biological carbon cycle with the relatively constant initial ratio to 12 C (Currie, 2004;Szidat et al, 2009). On the other hand, 14 C is completely depleted in fossil fuels due to radioactive decay.…”

Estimation of the fossil fuel component in atmospheric CO<sub>2</sub> based on radiocarbon measurements at the Beromünster tall tower, Switzerland

“…Radiocarbon is produced in the upper atmosphere during the reaction of neutrons with nitrogen induced by cosmic rays (Currie, 2004). In addition, nuclear bomb tests in the 1960s led to large radiocarbon input into the atmosphere, which thereafter decreased due to gradual uptake by the oceans and the terrestrial biosphere (Manning et al, 1990;Levin et al, 2010).…”

Bomb-Pulse Dating of Human Material: Modeling the Influence of Diet

“…From the peak in 1963, the level of 14 CO 2 has decreased exponentially with a mean life of about 16 yr (Ubelaker and Buchholz 2005), not due to radioactive decay but due to mixing with large marine and terrestrial carbon reservoirs. This "bomb pulse" of excess 14 C was recorded in all parts of the living biosphere (Currie 2004). The 14 C bomb pulse can be used to obtain age information in geosciences, forensics, and environmental sciences (Harkness andWalton 1969, 1972;Wild et al 2000;Goodsite et al 2001).…”