A team of researchers from the University of Maryland, USA has made a unique discovery: a series of dense structures completely unknown until now inside the Earth. Located about 3,000 kilometres deep, they are located under the Pacific Ocean, located exactly between the core and the planet’s mantle and, now, it is necessary to continue investigating to know the origin of their formation.
For many years, it has been known that earthquakes generate a series of seismic waves that move through this space, being able to modify their route, accelerate or even spread over thousands of kilometres, being captured by seismographs on the planet. These waves modify their movement if they encounter changes in the temperature, composition and density of the rocks, so a team of experts wanted to analyze what type of materials caused the variations.
To do this, the team of geophysicists at the University of Maryland, led by seismologist Doyeon Kim, used an algorithm with which to try to understand if these seismic waves could reveal any secret from the Earth’s interior. It was a computer system that has traditionally been used to try to discover the phenomena that occur in our galaxy. Conveniently, it was used to investigate what Earth’s ‘depths’ were like.
Once the system for the investigation was found, the experts did something never done before: simultaneously analyze thousands of recordings of seismic waves, all located under the Pacific Ocean basin. Never before has there been such a large sample of this type of element, taking into account a type of very specific waves called shear waves, with which they managed to discover numerous echoes that would explain the presence of unknown structures.
“We found echoes in about 40% of all seismic wave pathways. That was surprising because we expected them to be rarer and what that means is that the anomalous structures at the core-mantle boundary are much more widespread than previously thought. This shows us that this region has many structures that can produce these echoes, something that we had not realized before because we had a narrow vision,” explains Kim in a statement.
With this research, geologists have managed to discover that the waves that move between the nucleus and the mantle routinely change their movement at very specific and established points, something that unmistakably suggests the presence of structures that give rise to these changes. Its composition is unknown, although it has been discovered that they are more numerous than previously thought, according to the study published in ‘Science Mag’.
Now, following research will try to know what kind of materials form it and why they are there, two answers that can help us unravel some of our planet’s riddles, such as the “intricate processes that have caused our planet to evolve and change over time,” experts explain. Large structures of an unknown dense material that are 3,000 kilometres below our feet.