Ground motion is the movement of the

Earth’s surface Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

from

earthquakes An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they c ...

or explosions. Ground motion is produced by

seismic wave A seismic wave is a mechanical wave of acoustic energy that travels through the Earth or another planetary body. It can result from an earthquake (or generally, a quake), volcanic eruption, magma movement, a large landslide and a large ma ...

s that are generated by sudden slip on a fault or sudden pressure at the explosive source and travel through the Earth and along its surface. This can be due to natural events, such as

and volcanic eruptions, or human activities, such as the detonation of

nuclear weapons A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either nuclear fission, fission (fission or atomic bomb) or a combination of fission and nuclear fusion, fusion reactions (thermonuclear weap ...

. There are two main types of seismic waves: body waves and surface waves. Body waves travel through the interior of the Earth, while surface waves travel along the Earth's surface. Ground motion is typically caused by surface waves, which are the most destructive type of seismic waves. Ground motion is measured using a

seismometer A seismometer is an instrument that responds to ground displacement and shaking such as caused by quakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The out ...

, a device that detects and records the movement of the Earth's surface. Seismometers are used by seismologists to study earthquakes and other types of ground motion. The recordings produced by a seismometer are known as seismograms, and they can be used to study the characteristics of the ground motion, such as its duration, amplitude, and frequency. Ground motion is typically measured in three components: west-to-east, south-to-north, and vertical. Recordings from multiple seismometers can be combined to form a detailed model of the ground motion. This is known as a seismograph, and it can be used to study the spatial and temporal characteristics of the ground motion. Seismographs can also be used to create maps of the ground motion, which can help scientists understand the distribution and intensity of the seismic waves.

References

{{Seismology-stub Seismology

See also

References