Geophysics is the science of the Earth that is concerned with the study of the physical properties and characteristics of rocks, such as those properties that relate to magnetism, gravity, electricity, electromagnetism, radiation and thermal energy. Through data processing, it is possible to deduce a 2-D or 3-D model of the Earth and its layers and subsurface geologic structures. These geophysical data are derived from the variations or differences in the physical characteristics of Earth materials.