Earth’s magnetic poles are “unlikely” to swap anytime soon reveals a new analysis published yesterday in the Proceedings of the National Academy of Sciences.
An international team of researchers has studied Earth’s past geomagnetic activity, looking for the most recent near-reversal events. Their study finally puts to rest the recent speculations that our planet is headed for a magnetic polar reversal or excursion, Phys.org reports.
Earth’s magnetic field protects the planet from solar winds and harmful cosmic radiation. Generated deep within Earth’s core, the magnetic field extends from our planet’s interior out into space and is created by a fluid 1,242-mile-thick layer of iron, nickel, and other metals that wraps Earth’s inner core. This flow of liquid metals creates electric currents, which in turn produce magnetic fields, Physics.org explains.
Concerns that Earth’s magnetic field has weakened over the last two centuries, coupled with the discovery of the South Atlantic Anomaly — a weak area in the magnetic field that stretches from Chile in South America to Zimbabwe in South Africa — has given rise to theories that Earth’s magnetic poles could flip within the next 2,000 years.
Add NASA’s estimates that magnetic polar reversals have happened at least hundreds of times over the past three billion years, with one occurring about every 200,000 to 300,000 years. It’s been 780,000 years since the last time Earth’s magnetic poles switched positions and that’s how you end up with doomsday predictions that spell disaster for life on Earth.
However, researchers convey that there’s no cause to flip over the flipping of the magnetic poles, as this is not likely to happen in the near future.
“Our research suggests instead that the current weakened field will recover without such an extreme event, and therefore is unlikely to reverse,” study author Richard Holme, a professor of geomagnetism at the University of Liverpool, clarified in a statement.
Together with scientists from the University of Iceland in Reykjavik and the German Research Centre for Geosciences (GFZ), Holme studied the way Earth’s magnetic field looked during the two most recent geomagnetic excursion events, where the poles came close to reversing but recovered their original position.
This happened roughly 41,000 years ago, which became known as the Laschamp event, and again around 34,000 years ago, described as the Mono Lake event. But the shape of the magnetic field back then was not similar to its present situation, the researchers point out.
According to Holme, those two excursion events looked nothing like what’s currently going on with Earth’s magnetic field.
“By studying the two most recent excursion events, we show that neither bear resemblance to current changes in the geomagnetic field and therefore it is probably unlikely that such an event is about to happen,” he said in a statement.
The study did find a similarity between the present-day magnetic field and the way it looked during two other periods — one 49,000 years ago and one 46,000 years ago. Those also included an intensity structure similar to today’s South Atlantic Anomaly, albeit much stronger than that. But in both cases, the magnetic poles only wobbled without developing into a magnetic excursion or reversal, LiveScience reports.