A method for interpreting electromagnetic survey data includes acquiring
electromagnetic survey data near a top of a portion of the Earth's
subsurface. An initial model of the portion of the Earth's subsurface is
generated. The model includes at least spatial distribution of formation
resistivity within the portion. The initial model is applied to an
artificial neural network trained to generate expected electromagnetic
survey instrument response to the initial model. The acquired
electromagnetic survey data are compared to an output of the artificial
neural network. The initial model is adjusted, and the applying the model
to the artificial neural network and the comparing are repeated until
differences between the output of the network and the acquired survey
data fall below a selected threshold.