Geoscientists at the University of Southern California, the University of Los Angeles, the Chinese Academy of Sciences, Cornell University, the Institute of Geology at the University of Utah and the University of Utah have said they have detected structural changes near the center of the Earth.
The inner core of the Earth was previously thought to be solid. Image credit: USC Graphics/Edward Sotero.
Professor John Vidale, a researcher at the University of Southern California in Los Angeles, said:
“What we discovered is evidence that the surface near the inner core of the Earth is undergoing structural changes.”
Located 5,000 km (3,000 miles) on the surface of the Earth, the inner core is fixed by gravity within the outer core of the molten liquid. Until now, the inner core was widely considered to be a solid sphere.
“The original purpose was to further diagram the deceleration of the inner core. However, when I was analyzing decades of earthquake records, one dataset of seismic waves remained. It was strangely distinctive from that,” Dr. Vidale said.
“Later I realized I was staring at evidence that my inner core was not solid.”
In this study, the authors recorded seismic waves recorded by Yelson and Yellow Knife Receber Array Stations in North America from repeated seismic pairs in the North-South Sandwich Islands between 1991 and 2023.
One dataset of seismic waves from the latter station contained non-characteristic properties that researchers have never seen before.
“The dataset initially confused me,” Dr. Vidale said.
It was not revealed that seismic waveforms represent additional physical activity in the inner core until the team improved their resolution techniques.
Physical activity is best described as a temporal change in the shape of the inner core.
New research shows that surfaces near the inner core can undergo viscous deformation, altering their shape and shifting at the shallow boundary of the inner core.
The most obvious cause of structural changes is the interaction between the inner and outer cores.
“It is widely known that the melted outer core is a turbulent flow, but that turbulence has not been observed to contiguously contiguously to the inner core of the human timescale,” Dr. Vidale said. Ta.
“The first thing we're looking at in this study is the outer core that probably disrupts the inner core.”
“This discovery could open the door to uncover previously hidden dynamics deep within the Earth's nucleus, and lead to a better understanding of the Earth's thermal and magnetic fields.”
study Published in the journal Natural Earth Science.
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Je Vidale et al. Variations in annual scales at both rotation speed and surfaces near the inner core of the Earth. nut. GeosciPublished online on February 10th, 2025. doi:10.1038/s41561-025-01642-2
Source: www.sci.news
