Particle.news
Download on the App Store
5 ARTICLES
·
last wk.

Carbon-Rich Core Model Explains How Earth’s Inner Core Began to Freeze

Atomic-scale simulations indicate that about 3.8% carbon by mass would reduce the required supercooling to roughly 266°C.

Drawing of Earth with cutaway showing the mantle and inner and outer core. Magnetic field lines produced by the geodynamo extend into space and interact with the solar wind. The iron-rich core at Earth's center is slowly freezing from the inside out. This growth of the solid inner core powers the magnetic field that shields our planet from harmful space weather. How and when the inner core first began to freeze remains a mystery but new research shows that solving it could reveal the core's composition, giving us a clearer picture of Earth's deep interior. Credit: Dr. Alfred Wilson
Artist's concept of Earth's core (Credit: NASA/JPL)
Image

Overview

  • Researchers from the University of Oxford, the University of Leeds, and University College London report the findings in Nature Communications.
  • The team ran simulations of roughly 100,000 atoms at inner-core pressures and temperatures to track crystal nucleation from liquid iron.
  • Results show silicon and sulfur impede freezing, whereas carbon accelerates it, challenging common assumptions about the core’s light elements.
  • Extrapolating the simulations suggests 2.4% carbon still needs about 420°C of supercooling, but 3.8% carbon aligns with both nucleation and the observed inner-core size.
  • The study implies carbon may be more abundant in the core than previously thought and offers a new constraint for models of Earth’s thermal history and magnetic field generation.