Magnetic tensor gradiometry and marine CSEM

Abstract

In recent times, surveys employing tensor gradiometers have been used in mineral exploration. Some reasons for this are potential advantages such as improved resolution, data interpolation, noise suppression and relative insensitivity to survey orientation. The last two potentialities are particularly germane to marine CSEM surveys, which are typically sparsely sampled and require processing of measured fields to ensure that the correct vector component is analysed. In a series of numerical modelling studies of typical frequency-domain CSEM surveys in both shallow and deep water columns, this paper shows that tensor gradient measurements have advantages over conventional CSEM measurements in terms of target definition, especially when survey lines do not fall over target centres.