A method of attenuating interbed multiples in multiply-reflected seismic waves is performed at a computer system, the method including: providing multiple beams of seismic data and an earth model related to a geological volume; selecting one of the beams as an input beam associated with a pair of source and detector located near a top surface of the geological volume; determining at least one of (i) a source-side stationary pegleg arrival and a corresponding detector-side primary beam and (ii) a detector-side stationary pegleg arrival and a corresponding source-side primary beam; predicting an interbed multiples beam using at least one of (i) the detector-side primary beam delayed by the source-side stationary pegleg arrival and (ii) the source-side primary beam delayed by the detector-side stationary pegleg arrival; and deconvolving the predicted interbed multiples beam with the input beam to remove at least a portion of interbed multiples present in the input beam.