Modeling large-scale geoelectrical structures with inhomogeneous backgrounds using the integral equation method: applications to the bathymetry effect study in marine CSEM data

We apply a new formulation of the integral equation (IE) method with inhomogeneous background conductivity (IBC) for modeling marine controlled source electromagnetic (MCSEM) data in areas with significant bathymetric inhomogeneities. We also introduce an approach for accuracy control of the IBC IE method. This new approach provides us with the ability to improve the accuracy of computations by applying the IBC technique iteratively. This approach seems to be extremely useful in computing EM data for multiple geological models with some common geoelectrical features, like terrain, bathymetry, or other known structures. It may find wide application in inverse problem solution, where we have to keep some known geological structures unchanged during the iterative inversion. The effectiveness of this approach is illustrated by modeling marine controlled source electromagnetic (MCSEM) data in model with significant bathymetric inhomogeneities.