Scientists discover Earth’s core is growing ‘lopsided’ - and solve a 30-year mystery
The Earth’s core is growing lopsided, scientists have discovered, but it is unclear why.
The solid-iron core in the middle of the planet has been growing faster under Indonesia’s Banda Sea, seismologists at the University of California in Berkeley found.
The growth on one side of the molten metal is the product of iron crystals that form as the molten iron cools, but something in the Earth’s outer core or mantle under the south Asian country is removing heat at a faster rate than on the opposite side, under Brazil. The faster the cooling, the faster that iron crystallisation occurs – and the faster the growth increases.
Such a disparity has significant implications for the Earth’s magnetic field, and the convection currents in the core that generate the field are what protects us from dangerous solar particles.
While the core is solid iron, it is surrounded by a fluid outer core and then a mantle of hot rock. In the mantle and the outer core, heat from the crystallising iron and hotter rock in the mantle moves upwards towards the surface, pushing colder material down. This movement is what generates the magnetic field.