Geophysics, a key Earth science branch, studies the Earth's interior by analyzing variations in physical properties like magnetism, resistivity, conductivity, gravity, and seismic waves. It reveals seismic structures, thermal and radiation gradients, and Earth's layers (crust, mantle, outer core, inner core). Geophysics aids in earthquake monitoring with seismographs and has advanced significantly in the petroleum and mining sectors, locating oil fields, ore deposits, and underground reservoirs. Most geophysical research supports petroleum, mining, and groundwater exploration.