Life as we know it depends largely on the stability of the Earth’s magnetic field. But this stability (or the absence of this) depends in turn on factors that we still do not understand. Some of these factors are in the outer space, others instead are thousands of kilometers hidden under our feet.
From the bottom up. Huge geological structures located in the land mantle They could be contributing To destabilize the magnetic field that protects the land from radiation and particles from space. These are the “sunk continents”, the large provinces of low speed (LLVP).
Sunk continents. This last name is due to the fact that these rock masses located in the deep layers of the land mantle stand out from the rest of its surroundings because the seismic waves move more slowly through them. Through this method we know the existence of two large LLVP, one located under the African tectonic plaque and the other located under the peaceful plaque.
We do not know exactly what they are or what is the origin of these rock masses. A hypothesis indicates that could be remains of the impact between the primal earth and a second planet called Theia. The Moon would be one of the results of that impact, another would be that part of The remains of Theia would have been “embedded” on earth, specifically in the mantle, giving rise to these “lost continents.”
However, other studies have pointed out that these masses would be formed, at least partially of ocean cortex buried through subductive geological processes, which would make them more close to “lost continents” of the surface of the earth. The new study can be linked to this last hypothesis.
Fed by a “fire ring.” The team He modeled the movements Convectives of the land mantle, also creating a reconstruction of the possible movement of the tecton plates on the surface of the Earth in the last 1,000 million years. Thus they found indications that the African dough would contain older and more “mixed” than the peaceful mass, which would contain 50% more oceanic crust, a more “young” cortex and different from the surrounding mantle.
This could be explained with the call “Pacific Fire Ring”, A vast network of failures, many of them subductive that little by little they engulf part of the earth’s crust. This “banquet” would have been producing for at least 300 million years and would be serving to feed the Pacific LLVP.
The details of the study were published In an article In the magazine Scientific Reportsof Nature.
In diversity is the key. Until now, intuition pointed out that these two underground “continents” had a similar composition. The reason is precisely that the two slow down the passage of seismic waves in a similar way, which leads us to the intuition of thinking that these are very similar in their characteristics.
However, the team responsible for the new work indicates that this may not be the case. The reason is that the temperature is more than the material that makes these regions slow the waves that cross them.
The balance is complicated. The formations are more or less opposite in the Terrestrial globe, which in principle is great news: since these masses influence the way in which the temperature of the earth’s core is spread in higher layers, which in turn affects the conductive movements inside the nucleus of the planet.
Since these movements are those that allow the existence of a magnetic field On Earth, the way in which they occur has a lot of impact on this field. If the LLVPs are different, the way in which the field is generated ceases to be symmetrical as one would expect, which gives rise to the appearance of imbalances.
Discussing the different hypotheses. As we pointed out at the beginning, the new study can be linked to the idea that the LLVPs are the result of the sinking of earth cortex pieces and not the remains of a planet of the original solar system. Although the study does not offer conclusive evidence confirming this first hypothesis, It can be seen as a new more test in this address.
Image | Oxford University; Panton, Davies, et al. (2025) / NASA/Goddard Space Flight Center Scientific Visualization Studio
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