is a term for radiocarbon dating based on timestamps left by above-ground nuclear explosions, and it is especially useful for putting an absolute age on organisms that lived through those events.
Organisms at the base of the food chain that photosynthesize – for example, plants and algae – use the carbon in Earth’s atmosphere.They have masses of 13 and 14 respectively and are referred to as "carbon-13" and "carbon-14." If two atoms have equal numbers of protons but differing numbers of neutrons, one is said to be an "isotope" of the other.Carbon-13 and carbon-14 are thus isotopes of carbon-12.Aboveground nuclear testing almost doubled the amount of carbon-14 in the atmosphere. The black arrow shows when the Partial Test Ban Treaty was enacted that banned aboveground nuclear tests. A special kind of radiocarbon dating: Bomb radiocarbon dating.As we mentioned above, the carbon-14 to carbon-12 ratio in the atmosphere remains nearly constant.