geophysics is the application of physics to problems in earth science. many people are familiar with a branch of geophysics known as seismology, which is used extensively in the search for petroleum. besides seismology, geophysicists use gravity, magnetic and electromagnetic fields, and even remote sensing from satellites to probe beneath the earth’s surface. the obvious applications of geophysics are in oil and mineral exploration, but geophysics is widely used in any situation where information on the subsurface is required—for example, environmental assessment and remediation, civil engineering, oceanography and space exploration.