Tree Rings Chronicle a Mysterious Cosmic Storm That Strikes Every Thousand Years

There is a history of Earth's bombardment in the trees.

Radiation can alter nitrogen atoms in the atmosphere to create a form of carbon, which is absorbed by plants. A reliable record of radiation storms going back thousands of years can be found by linking spikes in carbon dioxide with the growth rings in trees.

The most significant of these events, known as Miyake events, occur once every thousand years. New research suggests that our leading theory about giant solar flares may be off the table.

We have a serious problem without an easy way to predict devastating events.

If one of these happened today, it would destroy technology including satellites, internet cables, long-distance power lines and transformers.

It would be impossible to have an effect on global infrastructure.

If you know how to look, the history of Earth's encounters with storms of Cosmic Radiation can be deciphered. The main clue is a radioactive form of carbon called carbon 14. Radiocarbon is relatively rare compared to other carbons on Earth. When Cosmic rays collide with nitrogen atoms, they cause a nuclear reaction that creates radiocarbon.

We only have a small amount of the stuff raining down on the surface because of our atmosphere's constant collision with the Cosmic rays. It gets caught in the tree rings. Since trees add a new growth ring every year, the deposition can be traced back through time and give a record of radiation activity over tens of thousands of years.

A spike in radiocarbon is a sign of an increase in Cosmic Radiation. Solar flares are a big cause of this. There are other possible sources that have not been ruled out. Solar flares have not been proven to be conclusive.

In order to understand the global carbon cycle, a team of researchers led by a mathematician from the University of Queensland used every scrap of tree ring radiocarbon data they could get their hands on.

The annual record of radiation in tree rings is created by the radioactive carbon-14 that is produced when the atmosphere is bombarded.

To understand the scale and nature of the Miyake events, we modeled the global carbon cycle for 10,000 years.

The team concluded that the timing and profile of solar flares is not consistent with the results of the modeling. Sunspot activity does not correlate with the spikes in radiocarbon. There were some spikes over time.

There was a lack of consistency in the radiocarbon profiles. Some trees in some parts of the world showed a sudden rise in radiocarbon for a year, while others showed a slower rise.

Rather than a single explosion or flare, what we may be looking at is a kind of astrophysical'storm' or eruption.

There are a number of candidates that the researchers don't know what the cause is. The radiation from a supernova event can travel across space. There are links between radiocarbon spikes and other possible supernova events but we have not seen any of them.

The 774CE radiocarbon spike is unlikely to have arisen from our Sun because of a solar superflare. Maybe there's some activity on the sun. There isn't a simple explanation for why Miyake events happen.

The researchers say this is a concern. A Miyake event could cause an internet apocalypse as infrastructure gets damaged, harm the health of air travelers, and deplete the ozone layer.

There is a one percent chance of seeing another one within the next decade.

We don't know what to do about it. The foundation for further research was laid by these odds.

The research has been published in a journal.