primary wave

American  

noun

1. Seismology. P wave.

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primary wave Scientific  

1. A type of seismic body wave in which rock particles vibrate parallel to the direction of wave travel. Primary waves are alternatingly compressional and extensional, and cause the rocks they pass through to change in volume. These waves are the fastest traveling seismic waves and can travel through solids, liquids, and gases.

2. Also called P wave

3. See Note at earthquake

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Etymology

Origin of primary wave

First recorded in 1915–20

Example Sentences

The first wave is a sound wave–like primary wave, or P-wave, moving at about four miles per second.

From Slate • Apr. 18, 2018

In this case the motion in different directions varies as cosθ, vanishing at right angles to the direction of propagation of the primary wave.

From Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 4 "Diameter" to "Dinarchus" by Various

It is accordingly necessary to suppose that the secondary waves start with a phase one-quarter of a period in advance of that of the primary wave at the surface of resolution.

From Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 4 "Diameter" to "Dinarchus" by Various

When the primary wave is plane, the area of the first Fresnel zone is πλr, and, since the secondary waves vary as r-1, the intensity is independent of r, as of course it should be.

From Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 4 "Diameter" to "Dinarchus" by Various

The fronts of these secondary waves all lie on a surface, which becomes the new surface of the primary wave.

From Heroes of Science: Physicists by Garnett, William