Geological records suggest that in Earth’s long history, hundreds of magnetic pole reversals have occurred, with the last one, known as the Brunhes-Matuyama, happening roughly 780,000 years ago.

Many scientists believe that we are in the early stages of the next one, which will occur when the iron atoms in Earth’s liquid outer core become reverse-aligned in such a quantity that they dominate the rest of the core’s atoms. Reverse-alignment happens in patches and spreads, with the fastest growing patch currently residing underneath Brazil and the South Atlantic ocean.

Credit: NASA

Worst case scenario

For some, a magnetic pole reversal means the end of the world, and that’s not being dramatic, it’s a seemingly plausible theory. When north turns to south, it may not just be compasses that get turned on their heads. Continents may jolt back and forth, causing huge land damage through earthquakes and tsunamis, climate change may be accelerated and huge numbers of humans and animals would meet their maker. Luckily for you and I, experts say that these visions of a huge environmental catastrophe are ‘pure fantasy’. Doomsday ‘preppers’ and ‘apocalypticists’, you can come out of your bunkers now…

The reason that dramatic events like earthquakes are unlikely is because of the difference between Earth’s liquid core, and its mantle. The mantle is responsible for tectonic shifts, which cause earthquakes, and although the mantle and liquid core do make contact, it would take millions of years for any changes in the liquid core to affect the mantle and disrupt the tectonic plates.

Alan Thompson, head of geomagnetism at the British Geological Survey has stated that during previous magnetic pole reversals:

“No worldwide shifting of continents or other planet-wide disasters occurred, as geoscientists can testify to from fossil and other records.”

aurorae europe NASA satellite

Credit: NASA

Science says…

The reversal of the poles can take up to 10,000 years to take full effect, so we shouldn’t really worry ourselves just yet. During this process, the magnetic field, which protects us from harmful solar radiation and solar winds by deflecting charged particles, will weaken considerably, to around 10% of the current strength. Then, for a while, it will appear that there are two poles, before fully changing to the opposite direction.

The greatest threat that this poses to humans is via the sun. With a weak magnetic field, we would be far more exposed to CMEs (Coronal Mass ejections), in which flaming hot materials from the Sun are thrown into space at high speeds (around 5,000,000mph), often in the direction of Earth. These would easily create temporary punctures in our ozone layer, causing massive exposure to UV rays. Some scientists predict that skin cancer rates would skyrocket.

Or, nothing happens…

There are some who are quite sure that people would feel absolutely nothing if the poles were to flip. Whilst sleeping, eating our lunch or working out at the gym, the magnetic poles of our planet could reverse, and we’d be none the wiser.

Those who go by this theory often believe that it will be technology that suffers in such a huge magnetic event. We’ve seen before that solar storms can cause huge malfunctions on satellites, interfere with communications, and cause blackouts. The best, and most recent example of this was the 2003 ‘Halloween Storm’ which caused blackouts across Sweden, it was a logistical nightmare for aviation and caused two NASA satellites to temporarily fail.

Or, the animals suffer the most…

While you may feel like you have an inner compass, and generally know where you are and which way you are facing, the inner compass of an animal is completely different. Many creatures have evolved to use ‘Magnetoreception’ for their internal navigation systems, and with a magnetic pole reversal, they’d be totally confused. Birds, whales, fish, bees, bacteria and turtles would all have to face a new challenge, and there’s no scientific precedent to suggest how they’d cope. However, many of these species existed during the last magnetic pole reversal, so perhaps they have a procedure!

Or, it gets aborted…aurorae magnetic pole reversal

Since the atom reverse alignment process takes many thousands of years and is in itself reversible, what may happen is that the magnetic poles do not switch, and the whole operation is aborted. 41,000 years ago, Earth experienced the Laschamp Event, in which the poles reversed temporarily over the course of 1,000 years, with the actual polarity change lasting just 250 years.

Magnetic pole reversal conclusion…

The one thing we do know is that many scientists feel that the process is already happening, and a research team at Berkeley revealed that the whole magnetic pole reversal can happen in less than one hundred years. The good news is, even if we are still alive when it happens, it’s not likely to damage the environment too badly.