Radio carbon dating examples
This man-made fluctuation wasn't a natural occurrence, but it demonstrates the fact that fluctuation is possible and that a period of natural upheaval upon the earth could greatly affect the ratio.Volcanoes spew out CO which could just as effectively decrease the ratio.Specimens which lived and died during a period of intense volcanism would appear older than they really are if they were dated using this technique.The ratio can further be affected by C-14 production rates in the atmosphere, which in turn is affected by the amount of cosmic rays penetrating the earth's atmosphere.Radioactive dating is very interesting because often this is where history and science mingle.
Precise measurements taken over the last 140 years have shown a steady decay in the strength of the earth's magnetic field.When bone fragments are found that are believed to be human or human-like, carbon-14 dating is often used to determine the approximate age of the remains.Another fascinating example is the Shroud of Turin (you might check this out on the Internet).Plants and animals naturally incorporate both the abundant C-12 isotope and the much rarer radiocarbon isotope into their tissues in about the same proportions as the two occur in the atmosphere during their lifetimes.
When a creature dies, it ceases to consume more radiocarbon while the C-14 already in its body continues to decay back into nitrogen.
C-14 is produced in the upper atmosphere when nitrogen-14 (N-14) is altered through the effects of cosmic radiation bombardment (a proton is displaced by a neutron effectively changing the nitrogen atom into a carbon isotope).