Earths Magnetic Poles Can Flip – And It's Long Overdue To Happen Again

Earths Magnetic Poles Can Flip – And It's Long Overdue To Happen Again

DR. ALFREDO CARPINETI

Something’s up with the Earth’s magnetic poles. Over the past few thousand years, Earth’s geomagnetic field has been getting weaker and weaker. If it decays enough, it could collapse altogether and flip the poles. North would become South and South would become North.

Looking at the geological history of Earth, magnetic field flips appear to occur every 200,000 to 300,000 years on average. Considering the last record of a total reversal was around 780,100 years. we are overdue for another.

Since the last pole flip, the events have been much shorter, with a temporary change 41,000 years ago that saw the poles reverse for 250 years before going back to the way they are today. 

The reason why this phenomenon takes place is not clear.

The Earth’s magnetic field is generated by the rotation of its molten iron outer core. The core is gradually cooling, which creates movement in the outer core due to convection, like a boiling pot. However, unlike a boiling pot, this movement is a dynamo, where a magnetic field is generated thanks to moving charges like in an electromagnet. Only 1 percent of the magnetic field escapes our planet's interior and becomes observable on the surface.

The pole-reversal explanation with the most support has something to do with the turbulence that the molten iron encounters as it moves. This chaos is likely to play a role, but how exactly it happens is still a mystery.

Evidence from the fossil record shows that living organisms didn’t suffer as a result of the poles switching around. There is also no suggestion that the flip led to more earthquakes, volcanic eruptions, or dramatic changes in the climate. Life and the planet will continue as we know it.

There is a question mark around modern-day technology, however. Our planet's magnetic field protects us against charged particles from the solar wind. This is particularly important during solar storms, where there is a higher-than-normal influx of energetic particles. These are again mostly harmless to us, but they might be devastating to our technology.

We don’t have much to go on to assess such a scenario. The best example might be the Carrington event, a powerful geomagnetic storm that happened in 1859. The storm was so powerful that aurorae were visible in the Northern Hemisphere all the way down to the Caribbean. Telegraph systems failed and, in some cases, gave operators electric shocks. 

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