primary wave

noun

1. Seismology. P wave.

primary wave

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

Word History and Origins

Origin of primary wave¹

First recorded in 1915–20

Example Sentences

Those are P waves, or primary waves, which occur first and travel the fastest, and S, or secondary waves, which travel slower but do the real damage we think of during a quake.

From Popular-Science

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

From Project Gutenberg

But a little consideration will prove that in that case the series of secondary waves could not reconstitute the primary wave.

From Project Gutenberg

For a point Q outside the shadow the integration extends over more than half the primary wave.

From Project Gutenberg

The operative part, or parts, of the curve are of course those which represent the unobstructed portions of the primary wave.

From Project Gutenberg

The conception of the lamina leads immediately to two schemes, according to which a primary wave may be supposed to be broken up.

From Project Gutenberg