Recently, a captivating discovery was made under the Pacific Ocean: land lost since 200 million years have resurfaced. The researchers of theETH Zurich a you California Institute of Technology are at the origin of this revelation, which could shake up our vision of plate tectonics and the ancient evolution of our planet. Basically, this new data pushes us to review certain geological principles that we thought were well established.
The earth’s mantle: a real pillar
The Earth's mantle is really a big part of the internal structure of our planet. It can reach up to 2 900 km thick and represents approximately 84% of total volume of the Earth. Mainly made up of minerals rich in silicates, iron and magnesium, it is mainly solid but behaves like a viscous fluid due to geodynamic movements. These movements are mainly responsible for tectonic phenomena such as earthquakes, volcanoes or even the movement of continents.
The intense heat coming from the Earth's core greatly influences the internal processes of the mantle. It causes convection currents where hot material rises and cold material sinks. This endless cycle actively participates in constantly reshaping the earth's surface.
What if we looked inside?
To explore these inaccessible depths, scientists rely on seismic waves generated by earthquakes. These waves pass through different layers of the earth, bending and reflecting. By analyzing the time between their transmission and reception by seismic stations scattered around the globe, geophysicists can build a detailed picture of what is happening inside the Earth.
Recently, an innovative method called complete waveform inversion has allowed researchers to reconstruct all of the seismic waves produced during an earthquake. Thanks to this, they discovered strange phenomena in areas thought to be tectonically calm, similar to a gravitational anomaly in the Indian Ocean.
Amazing discoveries at the heart of the mantle
The research revealed areas similar to fragments of tectonic plates in regions without ancient evidence of subduction. These findings challenge some conventional wisdom about plate tectonics and what ultimately happens to subducted plates.
Anomalies have also been spotted in the mantle using seismic waves. Some cold, dense regions could be made from ancient, preserved tectonic plates, while other anomalies could come from iron- or silica-rich rocks from the early Earth.
-What does this change for our geological vision?
These recent discoveries show that the Earth's mantle is much more complex than our previous models indicated. They also provide valuable clues about the ancient evolution of our planet, which requires us to seriously review our overall understanding of tectonic processes.
To refine these models, scientists now plan to use a sophisticated mix of electromagnetic, mineral and supercomputing data to get a more precise view of the inner workings of the Earth's mantle.
The continued study of the mantle reveals that there is still a lot to discover about our planet. Each technological advance allows modern scientists to deepen their exploration and understanding, little by little unveiling the mysteries buried beneath our feet. This endless quest only highlights how essential this research is to better understand not only past history but also the future geodynamic potential of our world.
A reaction? Leave a comment
Did you like this article? Subscribe to our free newsletter for engaging articles, exclusive content and the latest news.
Related News :