Filtering of interface waves by up/down splitting of multicomponent recordings at a liquid-solid or vacuum-solid interface

Multicomponent particle velocity recordings at the sea floor or at the surf ace of the earth should ideally be decomposed into up-going P- and S-waves to decouple the P- and S-wave information from subsurface layers. We show t hat Rayleigh waves excited by a land vibrator source, as well as Scholte (o r Stoneley) waves excited by the down-going field from a marine source arra y or sea floor vibrator source, are automatically filtered from the multico mponent recordings through the decomposition process. The interface wave co ntribution is zero on the up-going components, implying that the interface waves are left on the down-going components, which normally are of little i nterest in seismic exploration. The algorithm may straightforwardly be impl emented in slowness or wavenumber domain. The data must be adequately sampl ed to avoid spatial aliasing. Interface waves scattered in the near surface, being upwards reflected towa rds the geophones, will in principle not be removed by the decomposition pr ocedure. The decomposition strategy for attenuation of interface waves from multicomponent data should be a reasonable approximation when the layers c lose to the recording surface do not produce any significant scattered ener gy. The ideal medium is a thick non-scattering sediment column below the re corders.