A international group of researchers have identified a significant surge in radiocarbon levels dating back 14,300 years by examining ancient tree rings discovered in the French Alps
The significant rise in radiocarbon resulted from the largest solar storm ever recorded. A comparable solar storm in today’s world would have devastating consequences, potentially disrupting telecommunications, causing widespread power outages.
A collaborative study conducted by a global team of scientists has been published in The Royal Society’s Philosophical Transactions. This research offers a understanding of the Sun’s exceptional activities and the potential threats it presents to our planet.
Tree ring analysis
A group of scientists from Collège de France, CEREGE, IMBE, Aix-Marseille University, and the University of Leeds examined radiocarbon levels in ancient trees preserved within the weathered banks of the Drouzet River, situated near Gap in the Southern French Alps.
The tree trunks, considered subfossils due to their incomplete fossilisation process, were cut into small individual tree rings. Examination of these individual rings revealed an increase in radiocarbon levels precisely 14,300 years ago.
By correlating this radiocarbon surge with measurements of beryllium, a chemical element found in ice cores from Greenland, the researchers suggest that this spike was triggered by an immense solar storm, which would have released substantial amounts of energetic particles into Earth’s atmosphere.
Edouard Bard, Professor of Climate and Ocean Evolution at the Collège de France and CEREGE and lead author of the study, said: “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.”
Modern society’s vulnerability
According to scientists, if similar large solar storms were to happen today, it could have a harmful effect on our modern technology-dependent society. This could lead to the disruption of telecommunications, satellite systems, and power grids, resulting in financial losses. They stress the importance of comprehending the potential risks of such events, allowing us to get ready, fortify our communication and energy systems, and protect them from potential harm.
Tim Heaton, Professor of Applied Statistics in the School of Mathematics at the University of Leeds, said: “Extreme solar storms could have huge impacts on Earth. Such superstorms 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,”
“Such super storms could permanently damage the transformers in our electricity grids.”
Miyake events in history
Nine extreme solar storms, called Miyake Events, have been identified in the past 15,000 years. The most recent confirmed ones took place in 993 AD and 774 AD. However, the newly discovered storm from 14,300 years ago is the largest ever recorded, roughly twice the size of these two.
The nature of these Miyake Events is not fully understood, as they have never been directly observed instrumentally. This highlights our limited knowledge about the Sun’s behaviour and its threats to Earth. There needs to be a better understanding of what causes such extreme solar storms, how often they may occur, and if there’s a way to predict them.
The most significant solar storm that has been observed directly happened in 1859, called the Carrington Event. This event profoundly impacted Earth, destroying telegraph machines and creating a bright night-time aurora. However, the Miyake Events, including the newly identified 14,300-year-old storm, would have been about ten times larger in magnitude.
To create a longer timeline, researchers combined the widths of the individual tree rings from different trunks using a technique called dendrochronology. This helped uncover valuable details about past environmental changes and measure radiocarbon levels during an unexplored period of solar activity.
