Isotopic dating is based on Camgriil
[A Conventional Radiocarbon Age or CRA, does not take into account specific differences between the activity of different carbon reservoirs.A CRA is derived using an age calculation based upon the decay corrected activity of the absolute radiocarbon standard (1890 AD wood) which is in equilibrium with atmospheric radiocarbon levels (as mentioned previously, 1890 wood is no longer used as the primary radiocarbon standard, instead Oxalic Acid standards I and II were correlated with the activity of the original standard).The presence of bomb carbon in the earth's biosphere has enabled it to be used as a tracer to investigate the mechanics of carbon mixing and exchange processes.Ellen Druffel has called this the silver lining in thermonuclear bomb testing.The effect has been suggested as providing dates in error for the eruption of Thera which has been linked to the demise of the Minoan civilisation in the Aegean.One modern plant growing near the emanations had an apparent age of 1390 yr.
De Vries (1958) was the first person to identify this 'Atom Bomb' effect.
Thus, it dilutes the activity of the lake meaning that the radioactivity is depleted in comparison to 14C activity elsewhere.
The lake, in this case, has a different radiocarbon reservoir than that of the majority of the radiocarbon in the biosphere and therefore an accurate radiocarbon age requires that a correction be made to account for it.
Since about 1955, thermonuclear tests have added considerably to the C14 atmospheric reservoir.
This C14 is 'artificial' or 'bomb' C14, produced because nuclear bombs produce a huge thermal neutron flux.In this page, we consider natural reservoir variations and variations brought about by human interaction].