Tree rings offer insight into devastating radiation storms

A College of Queensland examine has shed new mild on a mysterious, unpredictable and doubtlessly devastating sort of astrophysical occasion.

A group led by Dr. Benjamin Pope from UQ’s College of Arithmetic and Physics utilized leading edge statistics to information from millennia-old timber, to seek out out extra about radiation “storms.”

“These big bursts of cosmic radiation, often called Miyake Occasions, have occurred roughly as soon as each thousand years, however what causes them is unclear,” Dr. Pope mentioned.

“The main principle is that they’re big solar flares. We have to know extra, as a result of if considered one of these occurred at this time, it might destroy know-how together with satellites, web cables, long-distance energy strains and transformers. The impact on international infrastructure can be unimaginable.”

Enter the common-or-garden tree ring.

First writer Qingyuan Zhang, a UQ undergraduate math scholar, developed software program to research each out there piece of knowledge on tree rings.

“As a result of you may depend a tree’s rings to establish its age, it’s also possible to observe historic cosmic occasions going again hundreds of years,” Mr. Zhang mentioned. “When radiation strikes the ambiance, it produces radioactive carbon-14, which filters via the air, oceans, crops, and animals, and produces an annual report of radiation in tree rings. We modeled the global carbon cycle to reconstruct the method over a ten,000-year interval, to achieve perception into the size and nature of the Miyake Occasions.”

The widespread principle till now has been that Miyake Occasions are large solar flares.

“However our outcomes problem this,” Mr. Zhang mentioned. “We have proven they are not correlated with sunspot exercise, and a few really final one or two years. Quite than a single instantaneous explosion or flare, what we could also be is a sort of astrophysical ‘storm’ or outburst.”

Dr. Pope mentioned the very fact scientists do not know precisely what Miyake Occasions are, or predict their prevalence, could be very disturbing.

“Based mostly on out there information, there’s roughly a one % probability of seeing one other one throughout the subsequent decade. However we do not know predict it or what harms it could trigger. These odds are fairly alarming, and lay the muse for additional analysis,” he concluded.

The analysis is printed in Proceedings of the Royal Society A, and was accomplished with assist from undergraduate math and physics college students Utkarsh Sharma and Jordan Dennis.