Bomb-Pulse Dating
Definition
Use of the post-1952 atmospheric 14C spike, produced by nuclear weapons testing, to date biological tissues formed since 1950. Because the spike rose and fell at a known rate, measuring 14C in a sample can fix its formation year within a few years for material from the 1960s-1990s period.
- Applicable period
- Tissue formed roughly 1955 to present
- Best precision window
- 1960s to 1990s samples
- Basis
- Known rise and fall rate of atmospheric 14C after 1950
- Forensic use
- Estimating formation year of human or biological tissue
Common questions
What tissues are typically used for bomb-pulse dating in human identification?+
Tooth enamel is a common target because it forms at a known age and does not remodel afterward, so its 14C level fixes a birth-year estimate. Other slowly turning-over tissues can also be used, while tissues that continuously remodel are less suited because they mix carbon from multiple years.
Why does precision fall for samples formed after the 1990s?+
The atmospheric 14C spike has been declining steadily as the ocean and biosphere absorb the excess carbon-14, so the curve is now much flatter than during the rising and peak years. A flatter curve means a given measurement is consistent with a wider range of possible formation years, widening the estimate.
Related terms
- AMS Radiocarbon Dating
- Accelerator Mass Spectrometry measurement of the ratio of carbon-14 to carbon-12 in a sample. It requires milligram-scale samples and produces a raw...
- Calibration Curve
- In RIA, a set of standards containing known concentrations of unlabelled analyte that are run alongside test samples. Bound radioactivity is measured...
- Dendrochronology
- The science of dating by tree-ring sequences. Each annual ring encodes the growing conditions of that year; matching ring patterns to a...
- OSL (Optically Stimulated Luminescence)
- A dating method that measures the accumulated radiation dose stored in mineral grains (usually quartz or feldspar) since they were last exposed...
- Terminus Post Quem (TPQ)
- Latin for 'limit after which.' The date of the youngest datable item in a context sets the earliest possible date for the...