The Earth's magnetic poles flip. What could cause this?

Scientists have been monitoring the movement of the Earth's magnetic poles since 1831, when the first measurements began. During this period, the north magnetic pole moved about 965 kilometers.

As reported by physicist Ofer Cohen Science AlertThis travel speed has increased from 16 to 54 kilometers per year recently. This increase may indicate the possibility of a reversal of the magnetic poles, as the North Pole moves towards the South and vice versa (without any change in the geographical poles). This hypothesis was verified by dating magma emitted by underwater volcanoes.

Cohen explains that volcanic rocks not only record the direction of the magnetic poles, but also the strength of the Earth's magnetic field. However, to confirm the pole reversal, data from at least 200 years would be needed.

The movement of the Earth's core, made up of liquid metals such as iron and nickel, is responsible for generating the Earth's magnetic field. According to Louise Beniusef, senior researcher at the Ministry of Science, Technology and Innovation (MCTI) and the National Observatory (ON), this field acts as a shield protecting us from cosmic radiation and solar wind, creating a barrier that also prevents the harmful effects of coronal mass ejections, in addition to enabling phenomena. Like the aurora borealis.

In general, the Earth's magnetic field can be understood as a shield that protects us from radiation, thanks to which a series of particles that come from the Sun along with sunlight are blocked and cannot pass through them. Some of these radioactive particles would be very harmful if they hit us.

Louise Beniusef, Senior Researcher at the Ministry of Science, Technology and Innovation (MCTI) and the National Observatory (ON)

In an interview with the Ulhar digital news programme, Beni Youssef explained that the Earth's magnetic field does not have the same values ​​everywhere on the planet. Some of them have different values ​​- anomalies.

This is what is happening with the South Atlantic Magnetic Anomaly (AAS), which has appeared in the media in recent days. “In the case here in Brazil, we have an anomaly in a very dense region, where the magnetic field has a relatively low value. This may pose a small technological problem. The region with a weaker magnetic field is more vulnerable to penetration by charged particles coming from the Sun.

Read more:

Regarding the reversal of magnetic poles, Beni Yusuf uses the compass as an example. “Because of its very state of formation, the Earth has a magnet. It is as if we were on a compass. The compass is pointed north. This means that there is a magnetic field, as if there were a magnetic dipole inside the Earth. This dipole varies with time. Obviously This variation on a very large time scale is subject to reversals.

The researcher explains that everything is at the origin of this field, which is in the outer core of the Earth. “The nucleus undergoes modifications, and among these modifications, the position of the poles logically ends up being reversed. In other words, the magnetic pole, which today is located in the geographical direction north, was in geological time the opposite. This reversal of poles is a natural phenomenon that occurs on Earth.

Do we need to worry? Bani Yusuf says no. “It doesn't happen on a human time scale, because it takes millions of years to happen.” During this process, according to Cohen, the direction of the field could leave the planet more vulnerable to cosmic radiation.

Although we are already seeing an acceleration of the poles shifting, it is unlikely that any human alive today will witness a complete reversal of the magnetic poles.

For Cohen, what we can expect are some of the effects of this movement. However, we are more likely to be protected from catastrophic events such as digital blackouts.

Continued understanding of these phenomena is critical to assess how these changes will impact life on Earth and ensure we are prepared for any future impacts.