Produced by: Mohsin Shaikh
Massive continent-sized mineral structures beneath Africa and the Pacific could be disrupting Earth’s magnetic field.
James Panton and Cardiff University researchers suggest these mantle anomalies may be unbalancing Earth’s magnetosphere.
The two structures, each up to 900 km high and thousands of km wide, were first revealed by seismic data in the 1980s.
Scientists believe these structures contain recycled oceanic crust, covering up to 30% of Earth’s outer core and slowing seismic waves.
The Pacific anomaly contains 50% more fresh oceanic crust, making it denser than the African mantle structure.
The structures block heat from escaping evenly, potentially disrupting convection currents that generate Earth’s magnetic shield.
The African anomaly has already been linked to a weakening magnetic field, raising concerns about future geomagnetic shifts.
The Pacific anomaly is fed by constant subduction, while the African anomaly contains older, more mixed crust.
Scientists need gravitational field data to fully understand how these mantle structures could alter Earth’s protective magnetosphere.