The surface of the internal nucleus of the earth can change shape and would have undergone over time structural transformations: a study recently published on Nature Geoscience and conducted by researchers of the University of Southern California (USC) led by John Vidale. So far the terrestrial internal nucleus was considered a completely solid sphere, but thanks to the study of seismic waves It turned out that the fluid external nucleus influences the shape of its surfaceThat It can therefore vary over time. The discovery is important because changes in the nucleus could influence the duration of the day and the earth’s magnetic field.
How the discovery on the structural changes of the terrestrial internal nucleus took place
The researchers discovered that the internal nucleus can change shape by analyzing the seismic waves of earthquakes. In fact, these provide information on the structure of the Earth as they propagate within it change characteristics according to the materials they encounter. In particular, they have been examined repeated earthquakes (i.e. occurred at different times in the same place) that occurred In 42 locations near the southern sandwich islands of Antarctica between 1991 and 2024. While the researchers analyzed the waves recorded in Yellowknife seismic station in Canada, they realized that the wave forms of some seismic signals have changed between 2004 and 2008. This change took place in correspondence with the internal nucleus and indicates a viscose deformation of its surface. In particular, on the border between external and internal nucleus they would be small depressions and reliefs. “For the first time we are seeing that it is deforming“Says John Vidale, seismologist of the University of Southern California in Los Angeles.
https://www.youtube.com/watch?v=vuqsdryq2JW
The cause of the change in the form of the internal nucleus of the earth and possible effects
The cause of the change of form was identified in theinteraction between the external nucleus and the internal nucleus. The external nucleus, in fact, being fluid is characterized by convective motions which disturb the internal nucleus, dragging the material and therefore deforming the surface. The anomalies of the seismic waves would also be connected to a change in the rotation speed of the internal nucleus. This layer, in fact, revolves faster than the earth, but recent studies say that he slowed down his rotation in 2009 and then start to rotate in the opposite direction. It is just as they were trying to understand the variations in the rotation of the internal nucleus that the researchers discovered the changes of form.
The variations of the internal nucleus could affect the movement of the external nucleus and the cloak, influenced the duration of the day and the terrestrial magnetic field.
The new studies of Californian researchers reveal internal dynamics to our planet so far unknown, but they need further insights capable of confirming the discovery.
