Recent research has revealed significant insights into the Earth’s inner core, particularly its shape, which appears to be changing over time. This inner core, a solid sphere of metal surrounded by a liquid outer core, has been observed for decades, with scientists suspecting it deforms as it rotates. New findings indicate the inner core has undergone shape changes over the past twenty years, identified through seismic waves from earthquakes strong enough to reach the Earth’s centre.
The research team utilised data from seismic waves and found that while the inner core once rotated faster than the Earth, its spin began to decrease around 2010. The study highlights that variations in seismic wave patterns now suggest deformation along the core’s surface could be occurring, possibly influenced by the dynamics of the outer core.
Dr John Vidale, a key author of the study published in Nature Geoscience, noted that observing such changes offers a deeper understanding of the forces at play within our planet. As the inner core continues to solidify, it is expected to grow while affecting the generation of Earth’s magnetic field, which shields us from solar radiation. While much remains to be explored, these findings enhance our understanding of the inner core’s complex behaviour and its implications for Earth’s long-term evolution.