The dimensionless quality factor. It is the ratio of the peak energy of a wave to the dissipated energy. As waves travel, they lose energy with distance and time due to spherical divergence and absorption. Such energy loss must be accounted for when restoring seismic amplitudes to perform fluid and lithologic interpretations, such as amplitude versus offset (AVO) analysis. Q is also described as the reciprocal of attenuation, but that is not strictly correct because the attenuation coefficient has units of inverse length.