geofüüsikat

Geofüüsika, the Estonian term for geophysics, is the science that studies the Earth's physical properties and processes using methods from physics. It covers the interior, surface, and near-surface environments, using measurements of gravity, magnetic fields, seismic waves, heat flow, and electrical and electromagnetic fields.

Geophysics uses a range of techniques. Seismology analyzes seismic waves to image the interior and monitor earthquakes. Gravimetry detects gravity-field variations to infer density structure. Magnetometry and geomagnetism investigate the Earth's magnetic field and its changes. Electrical and electromagnetic methods, including resistivity, induced polarization, magnetotellurics, and ground-penetrating radar, reveal subsurface conductivity and structure. Geodesy uses satellite and ground observations to determine shape, gravity field, and dynamics. Borehole measurements, thermal methods, and remote sensing complement surface surveys.

Subfields include seismology, geomagnetism, gravimetry, electrical geophysics, magnetotellurics, geothermal geophysics, hydrogeophysics, and geodesy. Applications span exploration for oil, gas, and minerals; subsurface imaging for engineering and environmental purposes; earthquake and volcanic hazard assessment; geothermal energy; groundwater and environmental studies; and archaeological investigations.

Modern geophysics arose from 19th- and 20th-century work in gravity, magnetism, and seismology, expanding with airborne, marine, and borehole surveys and digital data processing. It is taught worldwide in universities and practiced by research institutes, energy companies, and government agencies. International organizations such as the American Geophysical Union (AGU) and the European Geosciences Union (EGU) support geophysical research and data sharing.