About 2,500 years ago, the Greek philosopher Pythagoras wondered about the true shape of our planet. Through research using two cities as a basis, the philosopher, in a series of calculations, was able to almost correctly state the spherical diameter of the Earth.
Since then, several other studies have emerged, proving the shape of our planet more than once. But like almost everything in Science, this has led to even more questions, such as: is the Earth round? What is in the middle of it?
Nowadays, with the evolution of the scientific method and the creation of technologies, as well as space exploration, we know that the Earth is made up of five layers, namely: crust, upper mantle (or asthenosphere), lower mantle, outer core and inner core.
Some scholars say that for those who do not study Geology in depth, it is only necessary to have knowledge of the Crust, Mantle and Core divisions. However, for those who study the subject, or who are interested in it, the five divisions are the correct thing to know.
But what do these divisions imply for humanity? Well, for anyone who has ever heard of an earthquake, a volcanic eruption, or who lives at high altitudes, this is essential knowledge of the world.
It is the interaction between these layers, proportional to the differences in composition and physical state, that leads to these events.
For example, tectonic plates are large pieces of crust that move over the upper (plasma) mantle, driven by internal energy generated by radioactive decay in the Earth’s core.
Traces of Earth’s crust around the core
As in the example above, tectonic plates are moved by what is known as convection currents. These currents are masses of liquid rock (magma) that flow from the Earth’s interior to the surface. In this way, they cause a new ocean floor to be created.
Consequently, this “release” of magma onto the surface will create new rocks, that is, a new crust. This new crust will gradually push the old one, and this leads to the phenomenon of continental movement.
Therefore, if there is a creation, there will consequently be a “destruction” or “recycling”. This happens in subduction zones, where the densest tectonic plates sink back into the Earth’s mantle.
This is the stage where the most recent discovery made by scientists and published in the magazine Science Advances. Study carried out using seismic waves captured by fifteen monitoring facilities in Antarctica over three years.
Those responsible for the research discovered that there are points where there is a slower movement of the Earth’s magma. These points were called ultra-low velocity zones (ULVZs).
But what does this mean in practice? It means that, in the zone that comprises the boundary between the outer core and the lower mantle, ULVZs end up generating the emergence of agglomerations of ancient rock formations.
And as we know, all the formation that returns to the interior of the Earth comes from the ocean floor, so this is nothing more than ancient rocks that made up the ocean millions of years ago.
Logically, as in all science, there is still much to discuss regarding this discovery. However, the scientists responsible for the research believe that perhaps the entire core-mantle boundary is covered by a thin layer of ancient oceanic rocks.
