Formulae for the moments of the magnetic-field response can be derived for simple models like a half-space, thin and thick sheet. For these models, formulae only exist for lower-order moments. Assuming the conductance is finite, we can derive expressions for multiple order moments. As an example, we derive moment formulae for a smooth Gaussian conductivity distribution and use these to invert airborne electromagnetic data from an area in the Athabasca Basin of Canada. If we constrain the Gaussian model to be similar to a thin sheet or a thick sheet at the surface, we get estimates of the overburden depth or thickness which are much greater than what is known from drill information. However, if we solve for the three Gaussian parameters, then we find that the depth of the most conductive part of the overburden is realistic, being above the base of overburden as determined from drilling. Features of geological interest can be identified from the derived images that are not apparent on the original data.
Presentation Date: Wednesday, October 14, 2020
Session Start Time: 1:50 PM
Presentation Time: 2:15 PM
Location: Poster Station 2
Presentation Type: Poster
