The Earth's magnetic field is a kind of invisible superhero: it is always there, to protect us from radiation, ready to deflect the most harmful particles from the Sun. Like all superheroes, however, he too has moments of crisis. Some clues really suggest that we are about to undergo an epochal revolution: a new reversal of the magnetic field.
The mystery of the magnetic reversal
We still don't have a definitive explanation for what causes the magnetic field to reverse. However, scientists think the phenomenon may be related to the dynamics of terrestrial core: in particular the outermost one, which is in the molten state. This moving nucleus gives birth to something called geodynamo, a phenomenon that generates our magnetic field.
Over time, the geodynamo undergoes variations. Alterations that lead the magnetic field to weaken and move chaotically until it reaches a complete inversion, with the north and south magnetic poles exchanging places.
Hints of an impending reversal
Why do scientists think we are about to see a magnetic field reversal? There are two main clues that led them to this conclusion.
First, an anomaly we told you about some time ago. It is a weak and expanding magnetic field zone, he said South Atlantic anomalywhich covers about 20% of the earth's surface. This phenomenon is usually a warning sign of an impending capsizing.
Second, the last reversal dates back to 780.000 years ago, a period more than double the average between two events. In other words, we would even be "late" on the expected times for the occurrence of this phenomenon.
A future... multipolar
No, I'm not talking about geopolitics. Scientists' analyzes believe it is probable that more magnetic poles will also be created before the magnetic field reversal, and this aspect is of great concern.
Why? The effects could weaken our natural shield: a sort of "kryptonite" for our superhero, the magnetic field, which would cause him to lose up to 90% of his ability to shield us.
The consequences? Strong increase in the effects of solar winds, with a consequent increase in cases of cancer, technological malfunctions (many of our satellites and telescopes could suffer irreparable damage) and areas of the Earth that would become uninhabitable.
When will it happen? And how long?
It's frustrating not knowing exactly when it will happen, but this phenomenon somehow hangs over us: scientists do well to prepare for this eventuality, by studying the phenomenon and trying to predict its effects.
We have only a vague inkling of the impact of something like this. It comes to us from the study of an "episode" from over 40.000 years ago called Laschamps excursion. A relatively rapid (250 years) reversal with catastrophic effects. Let's hope it isn't anything like that: after all, second another study the magnetic field reversal that occurred 780.000 years ago took 20.000 years to complete.
If so, better slowly.
