Overview
- A peer-reviewed Nature Geoscience study led by the University of Liverpool identifies two continent-sized, ultra-hot rock regions at the base of the mantle, roughly 2,900 kilometers deep, encircled by a pole-to-pole ring of cooler rock.
- Simulations could only reproduce key features of Earth’s magnetic record when strong thermal heterogeneity at the core–mantle boundary was included, matching palaeomagnetic observations over hundreds of millions of years.
- The models indicate that liquid iron beneath the hotter regions can stagnate, while flow is more vigorous elsewhere, imprinting persistent, longitude-dependent signatures on the magnetic field.
- Findings challenge the assumption that the time-averaged field behaves as a simple bar magnet and carry implications for reconstructing past continental positions, ancient climate, paleobiology, and natural resource formation.
- The conclusions rest on indirect evidence and computationally intensive modeling, and the authors note that further data and refined simulations will be needed to test and sharpen the proposed mechanisms.