In new research, scientists from the University of Leeds and elsewhere measured radiocarbon levels in ancient trees preserved within the eroded banks of the Drouzet River in the Southern French Alps. The tree trunks, which are subfossils, were sliced into tiny single tree-rings. The analysis of individual rings identified an unprecedented spike in radiocarbon levels occurring precisely 14,300 years ago. By comparing this radiocarbon spike with measurements of beryllium, the authors propose that the spike was caused by an extreme solar storm that would have ejected huge volumes of energetic particles into Earth’s atmosphere.
“Radiocarbon is constantly being produced in the upper atmosphere through a chain of reactions initiated by cosmic rays,” said Professor Edouard Bard, a researcher at the Collège de France and CEREGE.
“Recently, scientists have found that extreme solar events including solar flares and coronal mass ejections can also create short-term bursts of energetic particles which are preserved as huge spikes in radiocarbon production occurring over the course of just a single year.
“Extreme solar storms could have huge impacts on Earth,” said University of Leeds Professor Tim Heaton.
“Such super storms could permanently damage the transformers in our electricity grids, resulting in huge and widespread blackouts lasting months.”
“They could also result in permanent damage to the satellites that we all rely on for navigation and telecommunication, leaving them unusable. They would also create severe radiation risks to astronauts.”
Nine such extreme solar storms — known as Miyake events — have now been identified as having occurred over the last 15,000 years.
The most recent confirmed Miyake events occurred in 993 CE and 774 CE.
This newly-identified event occurred 14,300 years ago, and is the largest that has ever been found — roughly twice the size of these two.
According to the team, the occurrence of similar…
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