1. A method executed by a computer system, comprising: applying, using a multidimensional model, a multidimensional wavefield extrapolation on a first survey data gather for a target physical structure, to predict data representing a first multiple, the multidimensional model being of a layer in which the first multiple occurs; producing modified survey data by performing a subtraction of the predicted data representing the first multiple from the first survey data gather; applying, using the multidimensional model, a multidimensional wavefield extrapolation on a second survey data gather generated from the modified survey data, to predict data representing a second multiple, wherein the first survey data gather is one of a common shot gather and a common receiver gather, and the second survey data gather is a different one of the common shot gather and the common receiver gather; combining the first multiple and the second multiple to produce data representing total multiples; and subtracting the total multiples from the first survey data to produce survey data with the total multiples attenuated, the survey data with the total multiples attenuated representing reflections from the target physical structure.