1. A method for interpreting electromagnetic survey data, comprising: acquiring electromagnetic survey data near a top of a portion of the Earth's subsurface; generating an initial model of the portion of the Earth's subsurface, the model including at least spatial distribution of formation resistivity within the portion; applying the initial model to an artificial neural network trained to generate expected electromagnetic survey instrument response to the initial model; comparing the acquired electromagnetic survey data to an output of the artificial neural network; and adjusting the initial model, and repeating applying the model to the artificial neural network and the comparing until differences between the output of the network and the acquired survey data fall below a selected threshold.