The Earth's magnetic field plays a significant role in the order of life, not only directing compasses to the north but also keeping dangerous cosmic radiation from entering the atmosphere. As long as this force is kept in place, life goes on.

The catch is, the magnetic poles occasionally goes through what's called a geomagnetic reversal, as discussed in a paper published in The Conversation by University of Rochester's John Tarduno and Vincent Hare. Every now and then -- anywhere from hundreds of thousands of years to millions -- the north and south magnetic poles actually swap places. During this reversal, the magnetic field weakens, leaving the Earth without protection.

Magnetic field has been decreasing for over a century

The last full reversal of the magnetic poles happened about 780,000 years ago, long enough ago that it wouldn't be strange that another one could be on its way soon. Findings collected throughout the past few decades seem to support the claims that a reversal is due.

For one, the magnetic field has actually been weakening in the last 160 years, particularly in a vast area in the Southern Hemisphere. This spot, known as the South Atlantic Anomaly, stretches from Zimbabwe to Chile. Here, the field gets so flimsy that satellites flying over the region are actually at high risk from radition that can mess with its electronics.

In the analysis of a model of the Earth's outer core, it was even revealed that a small patch underneath southern Africa already exhibits reversed polarity. If a compass is somehow inserted in the core-mantle boundary of this region, the north would actually point south. When numerical simulations were conducted, results show that patches like this occur right before geomagnetic reversals.

What does a reversal mean for Earth?

The possible effects of a reversal of the planet's magnetic poles are endless, from interfering with navigation systems to creating problems with electrical transmissions. Due to the amount of radiation that enter the atmosphere during the phenomenon, the health of humans could also be negatively affected such as an increase in cancer rates.

In another paper published in The Conversation, University of Leeds associate professors of geophysics Phil Livermore and Jon Mound pointed out that electronic disruptions would have major impact that could cost up to tens of millions of dollars every day. A previous study even suggested a connection between geomagnetic reversals to mass extinctions.