The inner workings of the Earth

Geoscientists have discerned that movements seen on the Earth's surface are likely driven by a massive and deep recycling of geological material. An important element of this scenario appears to be the dynamic boundary between the Earth's core and mantle. Investigations of the motions within the planet involve disciplines such as seismology, mineral physics, convection modelling, geodesy and geomagnetism. The paper presents the current understanding of the structure and dynamics of the Earth's interior, and discusses some speculative ideas. There are sections on: plate tectonics, mantle convection, thermal boundary layers, seismic tomography, thermal and chemical models of the core-mantle boundary (CMB), mineral phase changes, and the CMB and the geomagnetic field. -G.E.Hodgson