Research results published in Nature Geoscience propose that the Earth's interior nucleus may have changed form over the last 20 years. So far, scientists thought it was completely permanent. The observed deformations are most likely due to external nucleus disorders.
The Earth's core is the deepest part of our planet, consisting of the interior and outer nucleus. The erstwhile is referred to as a solid, uniform, rigid and unchanging sphere of metal. The outer nucleus is liquid, and thanks to gravity and density differences, it is liable for the interior nucleus.
A squad of scientists from the University of confederate California (USC) challenged this view. In Nature Geoscience, prof. John Vidale's group discovered evidence that the interior surface of the Earth's nucleus could undergo structural changes. According to scientists, changes in the form of the interior nucleus can affect its rotation, which, as previously shown, subtly modifies the dimension of the day on Earth. However, this effect is so tiny that it remains unnoticed in everyday life.
In the analysis of seismograms from the past fewer decades, scientists have come across an different set of data. 1 set of seismic waves was importantly different from the others. And it was only after any time that it was realised that they were looking at evidence suggesting that the interior nucleus is not full solid," said Prof. Vidale.
He and his colleagues utilized seismic data from 121 earthquakes close the South Sandwich Islands in the Atlantic, which occurred from 1991 to 2024. They analyzed waves received by seismic stations in Fairbanks, Alaska and Yellowknife, Canada. It was the data from this second location that revealed extraordinary properties of waves that scientists had never observed before.
At first, these data confused Prof. Vidale. It was only after his squad had perfected the analysis method that it became clear that the waves indicated additional physical activity in the interior nucleus. According to scientists, this means that the surface of the interior nucleus – contrary to what has been suggested so far – can change its form periodically. This is not a complete reconstruction, but subtle deformations that appear and disappear.
The best explanation for this phenomenon is that the surface of the interior nucleus is not completely rigid. The most probable origin of deformation is interactions between the interior nucleus and the external nucleus. It is widely known that the melted outer nucleus is turbulent (the movement of liquid metallic is chaotic and irregular), but it has never been observed that these turbulence affect the adjacent interior nucleus at a time scale that we can capture.
For the first time, evidence has been observed that the external nucleus may, however, interfere internally," explained Prof. Vidale. As he added, this discovery opens the way to a better knowing of the previously unknown dynamics occurring in the depths of the Earth. It can besides aid to realize processes related to the magnetic and thermal fields of our planet.
The results of the studies should be interpreted with caution and avoid the implications of the conclusions. There are inactive many unknowns. We cannot be 100% certain that our explanation of these changes is entirely correct – concluded Prof. Vidale. He besides pointed out that discipline is constantly developing and that the limits of cognition are inactive shifting. Like many another researchers, I was besides incorrect in the past – he admitted.
Continued here:
Discovering the fresh dynamics of the Earth's nucleus
