seismo

Seismo is a combining form derived from the Greek seismós meaning shaking or earthquake. In English and other languages it is used to form terms related to earthquakes and the propagation of seismic waves through the Earth. The term appears mainly in seismology, the scientific study of earthquakes, and in related fields such as geophysics and engineering.

Common seismo- terms include seismometer, seismograph, seismogram, and the adjective seismic. A seismometer is an instrument that detects ground motion; a seismograph is a device that records the motion, often the same instrument with a recording function. A seismogram is the graphical record produced by the instrument. Seismic is the broader adjective describing anything related to earthquakes or seismic waves.

Seismic waves are classified as body waves, including P-waves (compressional) and S-waves (shear), and surface waves that travel along the Earth’s exterior. P-waves are usually the fastest and arrive first; S-waves follow and cannot travel through liquids, helping reveal Earth's interior structure. The study of these waves allows scientists to infer properties such as material density and state within the planet.

Methods in seismology include seismic reflection and refraction, which probe subsurface layers, and seismic tomography, which constructs three-dimensional images of Earth’s interior. In exploration seismology, controlled sources (vibrations or blasts) generate waves to map underground formations.

Applications include earthquake detection and hazard assessment, engineering design for seismic resilience, and natural-resource exploration. Global networks of seismometers monitor the planet continually, enabling rapid earthquake alerts and advancing scientific understanding of seismic phenomena.