Comparison of the effects between single and multiple scattering on coda waves for local earthquakes

The effects of multiple scattering on coda waves have been investigated by an extension of the single-scattering theory. The contributions to the coda power due to multiple scattering from a uniform distribution of isotropic scatterers in a two-dimensional infinite elastic medium have been numerically evaluated. The results show that at shorter lapse time, the coda power is well explained by the single-scattering theory. At longer lapse time, the effects of multiple scattering need to be considered. The neglect of multiple scattering gives rise to an overestimation of the values of the quality factor ( Q ) by a factor of 1.4.