Geophysics is the lateral and vertical mapping of physical property variations that are remotely detected utilising non-invasive technologies to characterise the geology, geological structure, groundwater, pollution, and human artefacts beneath the Earth's surface. Many of these technologies have traditionally been used to explore economically valuable minerals including groundwater, metals, and hydrocarbons. Geophysics is the non-invasive study of Earth's subsurface state by the measurement, analysis, and interpretation of physical fields at the surface. Some investigations are performed to establish what lies right beneath the surface (the upper metre or so), while others go down to tens of metres or more. The circumstances of melting of Earth's most massive active volcanic system, the mid-ocean ridges, are being depicted by geochemistry and geophysics in very consistent ways. To improve our understanding of the Earth's structure, geophysical tools are increasingly utilised to map broad geological areas. Hydrocarbons, minerals, and groundwater are some of the resources that can be found and recovered. Potential CO2 deposits in the subsoil are being mapped.