New radiocarbon dating tool coming in the next few months

Scientists will recalibrate a key tool in determining how old a prehistoric sample is in the coming months.

A new calibration model for radiocarbon dating could have an effect on the estimated ages of many fossil finds – including Siberia’s oldest modern human fossils. They may not be as old as we thought previously.

To recalibrate the technique, researchers will take data points from tree rings, ocean and lake sediments, and stalagmites. That should extend the time frame for radiocarbon dating to 55,000 years ago, which is further back than the 2013 calibration update revealed.

ThHe announcement of a new calibration curve has some archaeologists excited about the change. Maybe I've been in lockdown too long,” Nicholas Sutton, an archaeologist at the University of Otago in New Zealand, said, “but … I'm really excited about it!”

The changes may be subtle but may still make a huge difference for those who are working to establish that events occurred in a specific window of time. 

Radiocarbon dating focuses on radioactive carbon-14, which is a naturally occurring substance absorbed by the atmosphere and food sources and living things. The radioactive carbon continues to decay, even after the plant or animal has died, and researchers measure the amount of that radioactive carbon that is left, in order to determine when the animal or plant died.

There’s a slight problem with the basic calculation – it assumes that carbon-14 has been constant in time and space, but it hasn’t.  Fossil fuel burning and nuclear bomb tests have altered the amount of carbon-14 in the air, and when the planetary magnetic fields have reversed, solar radiation has entered the atmosphere and added carbon-14 to the atmosphere.

This means the conversion tables don’t match up to calendar dates in all regions. New calibration curves will be released for the Northern Hemisphere, Southern Hemisphere, and marine samples. They will be published over the next few months in the journal “Radiocarbon.”