About 2,500 years ago, the Greek philosopher Pythagoras wondered about the real shape of our planet. Through research using two cities as a basis, the philosopher, in a series of calculations, managed 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 conditioned even more questions, such as: is the Earth round? What’s 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 composed 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 right 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 for getting to know the world.
For it is the interaction between these layers, proportional to differences in composition and physical state, that lead 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 the radioactive decay of 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 a convection current. These streams are masses of liquid rock (magma) flowing from the Earth’s interior to the surface. In this way, they generate a new ocean floor.
Consequently, this “release” of magma on the surface will create new rocks, that is, a new crust. This new crust will gradually push against the old one, and this leads to the phenomenon of continents moving.
Therefore, if there is a creation, consequently there will be a “destruction” or “recycling”. This happens in subduction zones, where denser tectonic plates sink back into the Earth’s mantle.
It is at this stage that the most recent discovery made by scientists and published in the journal 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 terrestrial magma. These points were called ultra-low speed zones (ULVZs).
But what does that mean in practice? It means that, in the zone comprising the boundary between the outer core and the lower mantle, the ULVZs end up generating the emergence of agglomerations of ancient rock formations.
And as you know, all the formation that returns to the Earth’s interior 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 about 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.
