Radiocarbon dating belfast
“There won’t be completely radical changes,” he said, “but I think everything from this time frame will be looked at again.” The Lake Suigetsu data could also be compared to other records to compare how atmospheric changes in carbon-14 match up to oceanic levels.“Having both allows you to look at how the atmosphere and the ocean are responding to each other, with important implications for understanding how the ocean was operating in the last Ice Age,” said Bronk Ramsey.“This dataset is the only continuous atmospheric record beyond the end of the tree rings,” said Paula Reimer, an archaeologist from Queen’s University Belfast in Northern Ireland who was not involved in the study.It extends over virtually the entire timespan for which carbon-dating is used—as far back as 60,000 years or so, when the the carbon-14 in the sample has decayed to unreliable levels.
“We must exercise some caution about any lake sediment record as it's always possible that there are missing layers.
But tree ring data only go back 13,000 years, and thus cannot be used to calibrate older dates.
“The hope has always been that we’d find records that we could use for the whole period of radiocarbon dating,” said Bronk Ramsey. Due to yearly changes in the lake’s surrounding vegetation, different types of organic material settled on its bottom in summer and winter.
Radiocarbon dating relies on a naturally-occurring radioactive isotope of carbon called carbon-14, which is formed in the atmosphere and taken up by plants.
Carbon-14 decays at a predictable rate, so by measuring its levels in archaeological remains, researchers can estimate when the ancient organisms died.
But levels of carbon-14 in the atmosphere vary from year to year, so scientists need to calibrate their estimates using long-running records of radiocarbon levels.