An international team of researchers has been studying stalagmites in China to help them track changes in the Earth’s magnetic field. They claim that they have uncovered evidence suggesting that pole reversal can happen over just a few centuries, and has done so in the past, a much shorter timescale than previously thought possible.

As reported in the Proceedings of the National Academy of Sciences, the work indicates that around 100,000 years ago, the magnetic field of our planet experienced a period of instability with rapid and temporary flips. The quickest of these happened in just 140 years.

“The record provides important insights into ancient magnetic field behaviour, which has turned out to vary much more rapidly than previously thought,” co-author Professor Andrew Roberts, from the Australian National University, said in a statement.

Researchers claim that if this were to happen today, it might have a huge effect on our society. The magnetic field protects us from the solar wind and, in particular, geomagnetic storms. When the most powerful of these extreme events happen, they are capable of penetrating the magnetic field and damaging our technology.

“Even with Earth’s strong magnetic field today, we’re still susceptible to solar storms that can damage our electricity-based society,” Roberts explained.

The issue would arise if a major storm struck during a pole reversal as this is when the magnetic field is at its weakest. This would wreak havoc on our way of life. “Hopefully such an event is a long way in the future and we can develop future technologies to avoid huge damage, where possible, from such events,” added Roberts.

There is often discussion of imminent pole reversal and subsequent disaster but as far as we know nothing is going to happen any time soon. The idea that we are due a pole reversal exists because the field has weakened by about 5 percent per decade in recent times, but this is not a clear indication that a reversal is about to happen.

This weakening condition has been seen before, according to geologists. It could merely be a blip in the ever-changing magnetic field. For the last 3.45 billion years the magnetic field has waned, strengthened, and flipped. It is a complex system and we have only had access to a small snapshot of it. We still have a lot more to learn.