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 making our planet behave like a magnet of great immensity. But what is this Earth’s magnetic field for?
What is the Earth’s magnetic field?
Before moving 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 we know as the core, where the magnificent processes occur 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, about 3 thousand kilometers deep, where the geomagnetic field is generated that keeps us safe from solar winds. This internal part of the Earth is composed of iron and nickel molten at high temperatures that behave like liquid, rotating and flowing as if thanks to the movements of the Earth. And it is precisely these two elements that serve as conductors and, thanks to this, generate electrical currents that make up the .
This rises beyond the core, extending up to about 500 kilometers high from the Earth’s surface. And it could even extend much further into space, if it weren’t for the solar winds that keep it in balance.
What is the Earth’s magnetic field 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 cosmic threats that threaten our planet. It mainly keeps us safe from , which is a flow of charged ion particles released 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 deflecting the solar winds. Above 500 kilometers in altitude, 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 see the amazing visual spectacles known as polar auroras during a certain season of the year. The polar lights are the name they receive in general, but in the north pole they are called the northern lights, while in the south they are called the aurora australis.
It is not uniform
The magnetic poles change location, since 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 functioning 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 planet’s history. However, scientists assure that this situation has not occurred in the last 780 thousand years. In case there is any doubt, it is also expected that this investment would take at least a thousand years, so there is no need to worry.
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 pole reversal.
There is even research looking at a pair of Earth’s mantle phenomena known as Large Low Shear Velocity Provinces (LLSVP), which are believed to be responsible for causing this anomaly in the field. The LLSVP are anomalous globes belonging to the lowest mantle, the one that borders the outer core.
According to research, these balloons are rather remains 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 whether this theory could turn out to be entirely true, the data suggests that it could be the answer to the reason for the South Atlantic anomaly.