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A study by scientists at the University of Southern California has found that the Earth's inner core undergoes structural changes under the influence of turbulence from the outer core, which can affect its rotation and shape.
The inner core was previously thought to be a solid sphere, but new data from seismic analysis suggest it is being deformed. John Vidale, the project's lead researcher, said: "What we ultimately found is evidence that the near surface of the Earth's inner core is undergoing structural changes."Scientists used records of 121 recurring earthquakes in the South Sandwich Islands area, collected from 1991 to 2024, which allowed them to observe previously unknown features of the core's behavior.
The unexpected results came from analyzing seismic waves from receiving stations in Alaska and Canada, where one data set had unusual properties. Vidale explains: "At first, the data set confused me", but further analysis showed that these changes are a manifestation of internal core activity. Scientists concluded that the changes in the inner core are associated with its interaction with the outer core, in particular, with turbulent processes that affect its shape and motion.
This discovery is the first evidence that the dynamics of the outer core directly affect the inner core on timescales noticeable to humanity. "What we're seeing in this study for the first time is probably the outer core disrupting the inner core.", – emphasizes Vidale. This research can help to better understand the Earth's magnetic and thermal fields and their role in long-term geophysical processes.
