LONDON: Tree-rings may serve as secret ‘time-markers’ that could help archaeologists date events of intense radiation bursts from thousands of years ago, a new Oxford study has found.
Harvesting such data could revolutionise the study of ancient civilisations such as the Egyptian and Mayan worlds, researchers said.
Until now scholars have had only vague evidence for dating when events happened during the earliest periods of civilisation, with estimates being within hundreds of years.
However, the unusually high levels of the radioactive isotope carbon-14 found in tree-rings laid down during the radiation bursts could help reliably pinpoint dates, according to researchers from Oxford University in the UK.
The distinct spikes act as time-markers like secret clocks contained in timber, papyri, baskets made from living plants or other organic materials, researchers said.
Scholars believe that intense solar storms caused major bursts of radiation to strike the Earth in 775 and 994 AD, which resulted in distinct spikes in the concentration of radiocarbon in trees growing at that time.
In the new study, researchers outline how they could detect similar spikes elsewhere within the thousands of years of available tree-ring material from across the world.
They said even a handful of these time-markers could allow them to piece together a reliable dating framework for important civilisations.
The crucial point is that the time-markers will also be present in every living plant or tree that grew at the time of a radiation surge, including in the timber used in ancient buildings or other artefact fashioned from the plants.
The paper suggests that the existing tree-ring data are likely to unveil other radiocarbon surges in particular years.
The problem, however, is that the tree-ring data is only available in blocks of decades rather than year by year.
The study proposes a cutting-edge mathematical method to filter out particular years within such a block when ‘change points’ in radiocarbon levels occurred.
It also adds that it is currently unclear how regularly the Earth has been hit by such intense bursts of radiation, and what the precise magnitude of the events might have been so finding new spikes will also help us understand past solar activity.
“Variations in atmospheric radiocarbon concentration are largely the result of carbon dioxide emissions from activity from volcanoes and the ocean, but they are also influenced by changes in solar activity,” said Michael Dee, from the University of Oxford.
“In the past, we have had floating estimates of when things may have happened, but these secret clocks could reset chronologies concerning important world civilisations with the potential to date events that happened many thousands of years ago to the exact year,” said Dee.
The study was published in the Royal Society Journal Proceedings A. (AGENCIES)
Follow our WhatsApp channel
