Geophysics, a branch of Earth sciences, is the study of the Earth by quantitative physical methods, especially by seismic, electromagnetic, and radioactivity methods. The theories and techniques of geophysics are employed extensively in the planetary sciences in general.

The field of geophysics includes the branches of:

• Seismology (earthquakes and elastic waves)
• Gravity and geodesy (the Earth's gravitational field and the size and form of the Earth)
• Atmospheric science, which includes:
• Atmospheric electricity and terrestrial magnetism (including ionosphere, Van Allen belts, telluric currents, Radiant energy, etc.)
• Meteorology and Climatology, which both involve studies of the weather.
• Aeronomy, the study of the physical structure and chemistry of the atmosphere.
• Geomagnetism (study of the Earth's magnetic field)
• Geothermometry (heating of the Earth, heat flow, volcanology, and hot springs)
• Hydrology (ground and surface water, sometimes including glaciology)
• Physical oceanography
• Tectonophysics (geological processes in the Earth)
• Geodynamics (numerical study of the inner Earth)
• Exploration and engineering geophysics (see also Archaeological geophysics)
• Geophysical Engineering
• Glaciology
• Petrophysics
• Applied geophysics
• Mineral Physics
• Engineering geology