1. n. [Geophysics]

The inability of a system to exactly match input and output amplitude, a general example being an electronic amplifier and the classic example being a home stereophonic amplifier.

See: bias,  dispersion,  distortion,  dynamic range,  harmonic distortion,  zero-phase

2. n. [Geophysics]

A change in the amplitude of a waveform that is generally undesirable, such as in seismic waves.

See: distortion,  seismic wave