Earth’s inner core reveals structural transformation as study detects viscous deformation 3,000 miles below surface

USC researchers discover Earth's inner core is deforming due to outer core turbulence. Learn how this structural shift affects the planet's rotation and day length.

By: AXL Media

Published: Feb 24, 2026, 7:56 AM EST

Source: The information in this article was sourced from ScienceDaily

The Breaking Development

New research published in Nature Geoscience has identified that Earth’s inner core is undergoing a profound structural transformation, moving away from the traditional image of a static, solid iron-nickel ball. According to lead investigator John Vidale, a professor of Earth Sciences at USC Dornsife, seismic waveforms recorded from repeating earthquakes show uncharacteristic properties that indicate physical activity within the core. This discovery suggests that the boundary between the inner and outer core is shifting and changing shape over time, a process known as viscous deformation.

Background and Context

For decades, the scientific community has debated the rotation of the inner core, specifically whether it rotates faster or slower than the Earth’s surface. In mid 2024, the same USC research team confirmed that the inner core began to slow down its rotation relative to the mantle around 2010. However, as Vidale analyzed multiple decades of seismograms, he encountered a dataset that stood out from the rest, eventually realizing he was looking at evidence that the core is not perfectly solid. The study utilized data from 121 repeating earthquakes near Antarctica’s South Sandwich Islands occurring between 1991 and 2024.

Key Players and Stakeholders

The study was led by John Vidale in collaboration with Wei Wang of the Chinese Academy of Sciences, using receiver-array stations in Alaska and Canada to capture seismic waves. According to the research team, the molten outer core, which is known for its turbulent motion, appears to be the primary driver behind these internal shifts. This discovery is of immense interest to the global geophysical community, as it provides a new lens through which to view the "geodynamo" effect, the process that generates Earth’s protective magnetic field.