Study: Earth's core is undergoing structural changes

A recent study published in the journal "Nature Geoscience" suggests that the Earth's inner core is less solid than previously thought and that it has undergone significant structural changes in the past two decades. According to research led by John Vidale, a professor at the University of Southern California, these changes are located close to the surface of the inner core and could be the result of viscous deformation caused by interaction with the outer core.

• Turbulence in the outer core, a disruptive factor

The Earth's outer core, made of molten iron, is known for its turbulent dynamics, but until now there was no evidence that these movements could influence the structure of the inner core on a human time scale. "It was known that the outer core is very active, but now we have clear evidence that this activity affects the inner core and that its shape changes over time," explains Vidale.

• Changes observed using seismic data

The research team used seismic data collected from 121 repeated earthquakes recorded between 1991 and 2024, located near the South Sandwich Islands in Antarctica. This data revealed differences in the behavior of seismic waves: those that crossed the inner core remained consistent, while waves that only touched it showed previously unexplained variations. The researchers believe that these differences are best explained by temporary changes in the shape of the inner core.

• Implications for understanding the planet

The inner core of the Earth plays a key role in maintaining the planet's magnetic field, and these new findings could fundamentally change the way we understand the internal dynamics of the Earth. The study suggests that these changes could be influenced by density anomalies in the lower mantle or by convective flows in the outer core, but further research is needed to confirm these hypotheses.