Scientists have made new revelations about our planet’s deepest secrets by identifying changes to the shape of Earth’s inner core. Researchers used earthquake data from 1991 to 2023 to study the solid inner core, finding signs of deformation over the past 20 years.
The team discovered that the inner core once spun faster than Earth itself but has slowed down in recent times. The current spin reversal is thought to be caused by changes in the shape of the inner core. This could hold clues about the forces deep inside Earth that power our magnetosphere, protecting us from solar radiation and deadly radiation.
The study built on previous research that found inner core rotation had changed over the past decade. However, this new study introduces a new perspective – non-rotational changes – adding another dimension to the discussion. The researchers found signs of deformation in waves from earthquakes that were strong enough to reach Earth’s center.
The team analyzed 168 paired waves from quakes in 42 locations near the South Sandwich Islands and detected amplitude changes in a type of core-penetrating P wave, hinting at deformations in the inner core’s shallowest level. The scientists believe the outer core is pushing on the inner core, moving it around.
These findings have implications for Earth’s long-term evolution, particularly regarding our magnetic field, which protects us from solar radiation. While a direct connection between life on Earth’s surface and the inner core remains distant, changes at the ICB (inner-outer core boundary) could still have an impact on Earth’s evolution.
Source: https://edition.cnn.com/2025/02/10/science/earth-inner-core-changing-shape/index.html