A composite image showing a tree ring and flames: UQ researchers used tree ring data to model the global carbon cycle to challenge common theory about Miyake events. Credit: University of Queensland
New light has been shed on a type of mysterious, unpredictable and potentially devastating astrophysical event, thanks to a study from the University of Queensland (UQ).
A team of researchers led by Dr. Benjamin Pope, from the UQ School of Mathematics and Physics, applied cutting-edge statistics to data from ancient trees to learn more about radiation “storms.”
“These huge bursts of cosmic radiation, known as Miyake Events, have occurred about once every thousand years, but it is not clear what causes them,” Dr. Pope said.
“The main theory is that they are huge solar flares. We need to know more, because if one of these were to happen today, it would destroy technology, including satellites, internet cables, long-distance power lines, and transformers.
“The effect on global infrastructure would be unimaginable.”
“Instead of a single instantaneous explosion or flash, what we may be seeing is a kind of astrophysical ‘storm’ or outburst.” — Qing Yuan Zhang
Enter the humble ring of trees.
First author Qingyuan Zhang, a UQ undergraduate math student, developed software to analyze all available tree-ring data.
“Because you can count the rings on a tree to identify its age, you can also look at historical cosmic events going back thousands of years,” said Mr Zhang.
“When radiation hits the atmosphere, it produces radioactive carbon-14, which filters through the air, oceans, plants and animals, and produces an annual record of radiation in tree rings.
“We modeled the global carbon cycle to reconstruct the process over a 10,000-year period, to gain insight into the scale and nature of the Miyake events.”
The common theory so far has been that the Miyake events are giant solar flares.
“But our results challenge this,” Mr Zhang said. “We have shown that they are not correlated with sunspot activity and, in fact, some last one or two years.
“Instead of a single instantaneous explosion or flash, what we may be seeing is a kind of astrophysical ‘storm’ or outburst.”
“The effect on global infrastructure would be unimaginable.” — dr benjamin dad
Dr. Pope said that the fact that scientists don’t know exactly what the Miyake events are, or how to predict their occurrence, is very disturbing.
“Based on available data, there is about a one percent chance of seeing another one in the next decade. But we don’t know how to predict it or what damage it can cause.
“These probabilities are quite alarming and lay the groundwork for future research.”
The research is published in Minutes of the Royal Society A.
Reference: “Modeling of cosmic radiation events in the tree-ring radiocarbon record” by Qingyuan Zhang, Utkarsh Sharma, Jordan A. Dennis, Andrea Scifo, Margot Kuitems, Ulf Büntgen, Mathew J. Owens, Michael W. Dee and Benjamin JS Pope, Proceedings of the Royal Society A Mathematics, Physics and Engineering Sciences.
DOI: 10.1098/rspa.2022.0497
The study was also completed with university math and physics students Utkarsh Sharma and Jordan Dennis.
The work was supported by a philanthropic gift to UQ from the Big Questions Institut.
