as a geophysics major, you will learn to apply the principles of physics to the study of the earth. in geophysics, evaluation of gravity, magnetic and electrical fields, seismic wave propagation and heat flow are used to deduce the earth's structure, composition, physical properties and dynamic processes. these studies may emphasize exploration geophysics, which uses geophysical techniques in the search for petroleum, natural gas, mineral deposits and groundwater resources. the techniques of geophysics are also used to investigate the shallow portions of the earth to determine conditions for the suitable location of dams, bridges, nuclear power plants, waste disposal sites and highways.