1. A method, executed by a computer, of updating a model of a subterranean structure, comprising: computing a partial decomposition of an operator that is used to compute a parameterization representing an update of the model, wherein the partial decomposition of the operator is selected from the group consisting of a partial singular value decomposition of the operator, and a partial eigendecomposition of a Fisher information operator; combining a term based on additional information with the partial decomposition of the operator to derive the update of the model.