But the correction introduces its own uncertainty, because the individual’s specific diet — how much marine food versus terrestrial food they consumed — affects how much of the marine reservoir offset applies to their date.

For Kwäday Dän Ts’ìnchi, whose isotopic evidence indicates a diet with substantial marine components, the marine reservoir effect is a significant consideration in interpreting the radiocarbon dates.

Researchers working on the project have applied corrections for the estimated proportion of marine food in his diet, based on the isotopic evidence, and have reported the corrected dates with the additional uncertainty that the correction introduces.

The result is a date range — approximately 300 to 550 years before the present — that is wider than it would be for an individual with a purely terrestrial diet, because the marine reservoir correction adds uncertainty on top of the standard radiocarbon measurement uncertainty.