Scientists have uncovered evidence of a colossal solar storm that struck Earth more than 14,000 years ago, an event so powerful that its effects are still recorded in tree rings today.
Detailed in the upcoming July 2025 issue of Earth and Planetary Science Letters, this ancient storm, which occurred around 12,350 BC, dwarfs any solar storm recorded in modern history and would wreak havoc on today’s technology if it were to happen again.
Known as a “Miyake Event,” this storm far surpasses the infamous Carrington Event of 1859, previously considered the benchmark for extreme solar activity.
Miyake Events are identified by spikes in carbon-14 levels found in tree rings—carbon-14 being a radioactive isotope produced when solar particles collide with Earth’s atmosphere. Since the first discovery by Fusa Miyake in 2012, at least six such events have been confirmed, including those in 774 AD and 993 AD.
The 12,350 BC Miyake Event stands out due to its immense scale and the challenges it posed to scientists trying to interpret it.
The spike in carbon-14 was detected in Scots Pine trees along France’s Drouzet River, and corroborated by matching beryllium-10 levels in Greenland ice cores, confirming the storm’s global reach.
However, interpreting these signals was complicated by the fact that the event occurred during the Ice Age, a period with very different atmospheric and climatic conditions compared to the relatively stable Holocene epoch when most other Miyake Events occurred.
To tackle this, researchers Kseniia Golubenko and Ilya Usoskin from the University of Oulu, Finland, developed a specialised chemistry-climate model. This model accounts for Ice Age variables such as ice sheet boundaries, sea levels, and geomagnetic fields, enabling accurate analysis of the ancient data.
Their findings reveal that the 12,350 BC storm unleashed a solar particle bombardment 500 times stronger than the largest solar particle storm recorded by satellites in 2005.
To put this in perspective, during the 2005 event, a passenger flying over the poles might have received a year’s worth of cosmic radiation in one hour; during the Ice Age event, the same dose would have been delivered in just eight seconds.
