The composition of the Earth is much more complex than what we can see with the naked eye, it is made up of different layers that each play a crucial role. In the center we have the person responsible for our planet behaving like a magnet of great immensity. But what is this Earth’s magnetic field for?
What is the earth’s magnetic field?
Before going on to understand the reason for the magnetic field, we must focus on what it is and how it originates. The Earth is made up of different layers, it is in its center, in the layer that we know as the nucleus, where the magnificent processes take place that allow the Earth to behave like a huge magnet and, therefore, have a magnetic field.
It is in the outer core inside the Earth, some 3 thousand kilometers deep, where the geomagnetic field that keeps us safe from solar winds is generated. This internal part of the Earth is composed of iron and nickel molten at high temperatures that behave like liquid, rotate and flow like water thanks to the movements of the Earth. And it is precisely these two elements that serve as conductors and that, thanks to this, generate electric currents that make up the Earth’s magnetic field.
It rises beyond the core, extending up to 500 kilometers above the Earth’s surface. And it could even extend much further into space, were it not for the solar winds that keep it balanced.
What is the Earth’s magnetic field used for?
Without the magnetic field there would simply be no life on Earth. Its main function is that it acts as a protective shield against the cosmic threats that touch our planet. Mainly it keeps us safe from the solar wind, which is a stream of charged ion particles blasted off from the upper solar atmosphere. These types of particles emit radiation that, without the magnetic field, would simply reach the Earth’s surface.
The region of the magnetic field known as the magnetosphere that extends above the ionosphere, is responsible for diverting the solar winds. Above 500 kilometers, the magnetosphere interacts with solar storms, deflecting charged particles toward the magnetic poles through field lines and a mechanism known as magnetic reconnection.
This process is what makes it possible to appreciate the amazing visual spectacles known as auroras in a certain season of the year. The polar lights is the name they receive in general but in the north pole they are called aurora borealis, while in the south they are called aurora australis.
it is not uniform
The magnetic poles change location, as they depend on the internal movements of the Earth’s core. The magnetic north pole, for example, moves at a rate of 40 kilometers per year, slow enough for our magnetic field-dependent electronic devices to continue to function optimally.
There are even records of reversals of the magnetic poles, that is, that the north and south magnetic poles exchanged positions at some point in the history of the planet. However, scientists say that this situation has not occurred in the last 780 thousand years. In case there is any doubt, this reversal is also expected to take at least a thousand years, so there is nothing to worry about.
South Atlantic anomaly
It is also known that the magnetic field is not uniform throughout the Earth. There is a region of lower magnetic intensity known as the South Atlantic anomaly, located between South Africa and South America. To date scientists have not been able to decipher with certainty what causes this phenomenon, although many speculate that it is an indication of the reversal of the poles.
There is even research looking at a couple of phenomena in the Earth’s mantle known as Large Low Shear Velocity Provinces (LLSVP), which are believed to be responsible for causing this anomaly in the field. LLSVPs are anomalous balloons belonging to the lowest mantle, the one that adjoins the outer core.
According to the research, these globes are rather remnants of the protoplanet known as Theia, which the Earth devoured 4.5 billion years ago, when the planet collided with the Earth. And although it is not known with certainty if this theory could be entirely true, the data suggests that it could be the answer to the reason for the South Atlantic anomaly.
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