A new study from the University of Queensland sheds new light on a mysterious, unpredictable, and potentially devastating type of astrophysical event.
To learn more about radiation “storms,” a team led by Dr. Benjamin Pope from UQ’s School of Mathematics and Physics used cutting-edge statistics on data from millennia-old trees.
“These massive bursts of cosmic radiation, known as Miyake Events,” Dr. Pope explained, “happen about once every thousand years, but the causes are unknown.”
“The most popular explanation is that they are massive solar flares. More information is needed because if one of these events occurred today, it would destroy technology such as satellites, internet cables, long-distance power lines, and transformers. The consequences for global infrastructure would be unfathomable.”
Here comes the humble tree ring.
Qingyuan Zhang, a UQ undergraduate math student, created software to analyse all available data on tree rings.
“Because you can count the rings on a tree to determine its age, you can also observe historical cosmic events that date back thousands of years,” Mr. Zhang explained. “When radiation enters the atmosphere, it generates radioactive carbon-14, which filters through the air, oceans, plants, and animals, leaving an annual record of radiation in tree rings. To gain insight into the scale and nature of the Miyake Events, we modelled the global carbon cycle over a 10,000-year period.”
Until now, the widely held belief has been that Miyake Events are massive solar flares.
“However, our findings call this into question,” Mr. Zhang said. “We’ve shown that they’re not related to sunspot activity, and that some only last a year or two. Rather than a single instantaneous explosion or flare, we could be witnessing an astrophysical ‘storm’ or outburst.”
According to Dr. Pope, the fact that scientists don’t know exactly what Miyake Events are or how to predict their occurrence is very concerning.
“According to available data, there is a one percent chance of another one occurring within the next decade. However, we have no idea how to predict it or what harm it may cause. These odds are quite alarming, and they lay the groundwork for future research “He finished.
The study, which was completed with the assistance of undergraduate math and physics students Utkarsh Sharma and Jordan Dennis, was published in Proceedings of the Royal Society A.