The Earth’s core remains a mystery in every possible way, and we have often paid more attention to what happens above us than to what happens under our feet. But a new study has shaken the scientific community. Now, and after many studies, researchers have confirmed the existence of two enormous structures at the base of the Earth’s mantle that could be affecting the stability of the planet’s magnetic field. Located thousands of kilometres below the surface, these formations are up to 900 kilometres high and thousands of kilometers wide! It’s as if two enormous invisible continents were floating inside the Earth, without us realizing it. But the most surprising thing is that they could be altering the balance of our magnetic field, the natural shield that protects us from solar radiation and space dangers.
This discovery not only forces us to re-examine what we know about the internal structure of our planet, but it could also have implications for the future of humanity. Imagine if these masses of material are affecting the Earth’s magnetic stability, we could face unexpected phenomena in the coming centuries… We’ll tell you everything they’ve discovered.
What are these structures and how did they form?
These anomalies have been dubbed low mantle velocity regions (LLVPs), and are areas where seismic waves travel more slowly than normal, indicating that they are made of a different material than the rest of the mantle.
These structures are not new, that is, they have not emerged now, but their existence was already known in the 1980s due to various seismic studies. However, until now their origin and function were not well understood, and it was James Panton’s team who demonstrated that they are different from each other. The Pacific LLVP is denser and contains more remains (53%) of recycled oceanic crust, while the African one is less dense and seems to be composed of older material.
So, this finding leads researchers to believe that these structures arose after billions of years of subduction and recycling of the oceanic crust, that is, they were formed over millions of years as fragments of tectonic plates sank into the mantle and accumulated, creating these structures.
How do they affect the Earth’s magnetic field?
At school they explained to us that the Earth’s magnetic field is generated in the outer core, where the constantly moving liquid iron acts as a huge dynamo. And this is where LLVPs could come into play, because this study would explain that these structures would be blocking the uniform dissipation of heat from the Earth’s core, which could generate variations in the mantle and, finally, affect the magnetic field, and so much so that the African LLVP has already been linked to anomalies in the magnetic field of that region.
But… what happens if the magnetic field weakens? Well, for us the magnetic field is like an invisible shield that protects us from cosmic radiation and solar storms. Without it, our planet would be a hostile place for life!!
Key differences between African and Pacific structures
The Pacific LLVP is in an area of intense tectonic activity, such as the Ring of Fire, and for millions of years the activity has been particularly intense, even sinking into the mantle and forming a dense and compact structure.
The African LLVP, on the other hand, is a real enigma: it is less dense, older and less stable, which has led scientists to wonder whether it could be related to important geological events in the history of the Earth, such as the breakup of ancient supercontinents.
Does this change anything for us?
For now, the impact of these structures is not known, but it is possible that they are contributing to stability. There are three key phenomena that this discovery could influence
- The first is through magnetic reversals, that is, we could experience changes in the magnetic poles, which have occurred in the past and could happen again now.
- On the other hand, we would be talking about unusual tectonic activity (which could influence a greater number of earthquakes and volcanic eruptions)
- Finally, greater exposure to solar radiation due to the weakening of the magnetic field.
What once seemed like a stable and predictable world is now revealed to be a planet in constant change, where hidden forces thousands of miles deep continue to shape our destiny without us realizing it, and how little we know about it!