Carbon 14 dating bomb curve

04 May

In the United States, for example, ivory taken prior to a 1989 worldwide ban on African elephant tusks may be legally traded, while new ivory is illegal to traffic, said Kevin Uno, a researcher at the Lamont-Doherty Earth Observatory at Columbia University in New York.

"I don't necessarily think this will save the elephants, but it's a critical tool to fight poaching of elephants," said Uno, co-author of a study detailing the technique, published today (July 1) in the journal Proceedings of the National Academy of Sciences.

Tissues formed after 1955 are dated to within 0.3–1.3 y of formation, depending on the tissue type, whereas tissues older than C dating of tissues has applications to stable isotope (paleo)ecology and wildlife forensics.

We use data from 41 additional samples to determine growth rates of tusks, molars, and hair, which improve interpretations of serial stable isotope data for (paleo)ecological studies.

Bomb tests generations ago could indirectly help fight illegal poaching of African elephants, new research shows.

Nuclear weapons tested in the atmosphere in the 1950s and '60s spread a radioactive variety of carbon worldwide, which was picked up by plants during photosynthesis and then deposited in the bodies of herbivores like African elephants.

For the remaining period 12,400-26,000 cal yr BP, the curve is derived from independently dated marine samples such as foraminifera and corals.

This causes apparent age differences, known as reservoir ages.

Various calibration programs are available to calculate the calendar age interval from the C data showing the bomb peak on the northern and southern hemisphere reflect the exchange between both hemispheres nicely.

The rise of the peak on the northern hemisphere, where the tests were made, is only a year earlier than on the southern hemisphere.

By looking at the levels of this carbon isotope — known as carbon-14 — in elephant tusks and ivory, researchers can find out how old they are.

(Isotopes are versions of elements that have differing numbers of neutrons in their nuclei.) Knowing the age of elephant tusks is important, since many regulations of ivory trade are date-specific.