Reversal of magnetic poles and disastrous consequences for life

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

Magnetic North Pole, heading towards Asia. The South Magnetic Pole is heading towards Australia. This is all part of a large-scale event - the change of the planet's poles.

The earth's magnetic field protects life from harmful solar radiation by deflecting charged particles. It surrounds our planet like an invisible force field.

This field is constantly changing, as shown by numerous global magnetic reversals, where the north and south magnetic poles are reversed.

During the reversal, the magnetic field will not be zero, but will acquire a weaker and more complex shape.

The power of this power shield that protects us from destructive cosmic radiation can drop to 10% of today's strength and the formation of magnetic poles at the equator, or even the simultaneous existence of several north and south magnetic poles.

Geomagnetic reversals occur on average several times per million years. The interval between reversals is very uneven and can be up to tens of millions of years.

Temporary and incomplete reversals are also possible, known as events and excursions, in which the magnetic poles move away from the geographic poles before returning back to their original locations.

The last complete coup, Bruns-Matuyama, took place about 780 thousand years ago. The time reversal, the Lashamp geomagnetic event, occurred about 41,000 years ago. It lasted less than 1000 years with the actual polarity reversal lasting about 250 years.

When the poles are inverted, the magnetic field weakens its protective effect, allowing increased levels of radiation to reach the Earth's surface.

The increase in the number of charged particles reaching the Earth will increase the risks to satellites, aviation and ground-based electrical infrastructure.

Geomagnetic storms give us a poor idea of what we can expect with a weakened magnetic shield.

In 2003, a so-called Halloween storm caused local power outages in Sweden, required reorientation of flights to avoid disconnections and radiation risks, and disrupted satellites and communications systems.

This storm was minor compared to other storms of the recent past, such as the superstorm "Carrington event" in 1859, which caused the auroras all the way to the Caribbean.

The impact of a major storm on today's electronic infrastructure is not fully known. Of course, any time spent without electricity, heating, air conditioning, GPS or internet will have serious consequences; widespread blackouts can lead to economic losses in the tens of billions of dollars a day.

In terms of life on Earth and the direct impact of the reversal on our species, we cannot definitely predict what will happen, since modern humans did not exist at the time of the last full reversal.

Several studies have attempted to link past reversals to mass extinctions - suggesting that some reversals and episodes of extended volcanism may be due to a common cause.

However, there is no evidence of any impending cataclysmic volcanism, and therefore we may have to contend with electromagnetic interference if the field reverses relatively soon.

We know that many species of animals have some form of magnetoreception, which allows them to sense the earth's magnetic field.

They can use it to aid long-distance navigation during migration. But it is unclear what effect such treatment might have on such species.

What is clear is that early humans did manage to survive the Lashump event, and life itself experienced hundreds of complete conversions, as evidenced by geological records.

The Earth's magnetic field is generated in the liquid core of our planet by slowly foaming molten iron.

Like the atmosphere and oceans, the way it moves is governed by the laws of physics. Therefore, we should be able to predict “core weather” by tracking this movement, just as we can predict real weather by looking at the atmosphere and ocean.

The pole reversal can be likened to a certain type of storm in the core, where dynamics - and the magnetic field - go awry (at least for a short time) before settling down again.

When Will the Next Pivot Happen?

We are “lagging” for a full turn. The Earth's field is currently decreasing at a rate of 5% per century.

Thus, scientists hypothesized that the field could change over the next 2000 years. But it will be difficult to establish the exact date.

The difficulties of predicting weather outside of a few days are well known, even though we live inside and observe the atmosphere directly.

However, predicting the Earth's core is a much more difficult prospect, mainly because it is buried under 3,000 km of rock, so our observations are scarce and unclear.

However, we are not entirely blind: we know the basic composition of the material inside the core and that it is liquid.

The global network of ground-based observatories and orbiting satellites also measures the change in magnetic field, which gives us an idea of how the liquid core moves.

The recent discovery of jet flow within the core underlines our evolving ingenuity and growing ability to measure and infer core dynamics.

Combined with numerical models and laboratory experiments to study fluid dynamics in the interior of a planet, our understanding is evolving at a rapid pace.

The prospect that we can predict the Earth's core may not be too far off.

We are entering the next solar cycle, which, according to astronomers, will be very weak. But since we are in the middle of the pole shift, the defenses are weaker, and even an average geomagnetic storm will have repercussions.

Be ready!