Seismic, volcanic, or explosive energy that travels through Earth's layers
This article is about waves that travel through Earth. For ocean waves sometimes called "seismic sea waves", see Tsunami.
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Earthquake swarm
Causes
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Characteristics
Epicenter
Epicentral distance
Hypocenter
Shadow zone
Seismic waves
P wave
S wave
Measurement
Seismometer
Seismic magnitude scales
Seismic intensity scales
Prediction
Coordinating Committee for Earthquake Prediction
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Adams–Williamson equation
Flinn–Engdahl regions
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p-wave and s-wave from seismographVelocity of seismic waves in Earth versus depth.[1] The negligible S-wave velocity in the outer core occurs because it is liquid, while in the solid inner core the S-wave velocity is non-zero
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 man-made explosion that produces low-frequency acoustic energy. Seismic waves are studied by seismologists, who record the waves using seismometers, hydrophones (in water), or accelerometers. Seismic waves are distinguished from seismic noise (ambient vibration), which is persistent low-amplitude vibration arising from a variety of natural and anthropogenic sources.
The propagation velocity of a seismic wave depends on density and elasticity of the medium as well as the type of wave. Velocity tends to increase with depth through Earth's crust and mantle, but drops sharply going from the mantle to Earth's outer core.[2]
Earthquakes create distinct types of waves with different velocities. When recorded by a seismic observatory, their different travel times help scientists locate the quake's hypocenter. In geophysics; the refraction or reflection of seismic waves is used for research into Earth's internal structure. Scientists sometimes generate and measure vibrations to investigate shallow, subsurface structure.
^G. R. Helffrich & B. J. Wood (2002). "The Earth's mantle" (PDF). Nature. 412 (2 August). Macmillan Magazines: 501–7. doi:10.1038/35087500. PMID 11484043. S2CID 4304379. Archived (PDF) from the original on 24 August 2016.
A seismicwave is a mechanical wave of acoustic energy that travels through the Earth or another planetary body. It can result from an earthquake (or...
A P wave (primary wave or pressure wave) is one of the two main types of elastic body waves, called seismicwaves in seismology. P waves travel faster...
resulting from a sudden release of energy in the lithosphere that creates seismicwaves. Earthquakes can range in intensity, from those so weak they cannot...
causation of seismic events and geodetic motions had come together in the now well-established theory of plate tectonics. Seismicwaves are elastic waves that...
measurements of an earthquake's seismicwaves as recorded on a seismogram. Magnitude scales vary based on what aspect of the seismicwaves are measured and how they...
reflected seismicwaves. The method requires a controlled seismic source of energy, such as dynamite or Tovex blast, a specialized air gun or a seismic vibrator...
generally encouraged the use of the term seismic sea wave rather than tidal wave. However, like tidal wave, seismic sea wave is not a completely accurate term...
A seismic shadow zone is an area of the Earth's surface where seismographs cannot detect direct P waves and/or S waves from an earthquake. This is due...
Seismic tomography or seismotomography is a technique for imaging the subsurface of the Earth with seismicwaves produced by earthquakes or explosions...
Reflection seismology Seismic refraction Seismic tomography Seismicwave Apollo 14 and 16 Active Seismic Experiments and Apollo 17 Lunar Seismic Profiling (PDF)...
refraction of seismic waves by rock or soil layers to characterize the subsurface geologic conditions and geologic structure. Seismic refraction is exploited...
Seismic velocity structure is the distribution and variation of seismicwave speeds within Earth's and other planetary bodies' subsurface. It is reflective...
sound waves are variations of the local pressure and particle motion that propagate through the medium. Other examples of mechanical waves are seismic waves...
gravitational waves and may cause shifts in the atoms. Hence, the magnitude of seismicwaves can be detected by a relative shift in the gravitational waves. The...
as mechanical waves (e.g. water waves, sound waves and seismicwaves) or electromagnetic waves (including light waves). It arises in fields like acoustics...
various seismicwaves in different regions and depths, those with fast wave speeds or diameters first arrive at the station, followed by other waves, resulting...
medium in question. Attenuation also occurs in earthquakes; when the seismicwaves move farther away from the hypocenter, they grow smaller as they are...
compressional (P-waves) while it absorbs the transverse or shear waves (S-waves). Outside the seismic shadow zone, both types of wave can be detected but...
mechanical sense, are commonly known as either Love waves (L waves) or Rayleigh waves. A seismicwave is a wave that travels through the Earth, often as the...
as a specialized air gun. Seismic sources can provide single pulses or continuous sweeps of energy, generating seismicwaves, which travel through a medium...
focal depth can be calculated from measurements based on seismicwave phenomena. As with all wave phenomena in physics, there is uncertainty in such measurements...
of the source event, such as measured by various seismic magnitude scales. The type of seismicwave generated, and its orientation. The depth of the event...
longitudinal waves, and surface waves. Some of the most common examples of mechanical waves are water waves, sound waves, and seismicwaves. Like all waves, mechanical...
mantle convection. Recording of seismicwaves from controlled sources provides information on the region that the waves travel through. If the density...
In physics, a standing wave, also known as a stationary wave, is a wave that oscillates in time but whose peak amplitude profile does not move in space...
and surface wave magnitude (Ms ) scales. Subtypes of the moment magnitude scale (Mww , etc.) reflect different ways of estimating the seismic moment. At...
make such structures more resistant to earthquakes. An earthquake (or seismic) engineer aims to construct structures that will not be damaged in minor...
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