A new physical mechanism is proposed, liquid-in-solid convection, whereby heat is transported upward in molten blobs of magma, which rise through the solid Mantle as solid melts above and congeals below them due to convection within the blob. The blobs are initiated by Rayleigh-Bernard convection within the molten core, a stochastic process. Sufficiently large blobs carry their own magnetic field due to a magneto-hydrodynamic dynamo effect. Rising MHD dynamos account for rapid changes in the surface geomagnetic field such as the South Atlantic Anomaly. In reality blobs are greatly elongated vertically and are manifested as “plumes”, “diapers” and “LVZs”.
Reid, J. (2019) The Fluid Catastrophe Cambridge Scholars Publishing, Newcastle upon Tyne, U.K.