Geophysics is a term that might discourage any but the most inquisitive Earth Scientist but, simply put, it is the study of the Physics of the Earth. As the Earth is very large and relatively slow-moving it is described by the classical Physics disciplines such as heat, gravity, magnetism, electricity, vibrations and waves. Everything we know about the deep Earth, apart from the superficial pinpricks provided by boreholes, we have learned from...