Physical principles reveal what lies beneath the surface and inside the planet. Geophysics applies the methods of physics to the study of Earth—its interior structure, composition, and dynamic processes. Seismology, gravity, magnetics, electrical methods, and heat-flow studies are major branches.

Seismic waves from earthquakes or controlled sources image crustal and mantle structure. Gravity and magnetic surveys detect variations in density and magnetization that outline buried geology. Electrical and electromagnetic techniques map conductivity contrasts useful in resource exploration and environmental work.

Geophysics underpins oil and mineral exploration, earthquake hazard assessment, and fundamental research into plate tectonics and the core. Because most of Earth’s interior is inaccessible to direct sampling, geophysical remote sensing remains indispensable. Advances in instrumentation and computing continually improve resolution and depth of investigation.

• Application of physics to Earth studies
• Includes seismology, gravity, and magnetics
• Images subsurface structure and properties
• Essential for exploration and hazard evaluation