In geophysics, the study of potential fields (gravimetry and magnetism) allow us to characterize geological bodies through two of their properties: density and magnetic response.
They are the two oldest and probably most complete methods since they provide us with information from the seafloor to the earth crust and even the mantle. The gravimetric method studies the contrast in density of the subsurface rocks and allows to differentiate between oceanic and continental crust. The magnetic method allows us to know the variations in the magnetic properties of the rocks of the crust. In marine research cruises it is very useful to determine the age of the seafloor, which has been key to formulate the theory of Plate Tectonics, the last scientific revolution in the 20th century. The combined study with the two methods allows us to reconstruct the tectonic evolution of Antarctica during the last million years.