Geologically constrained 2D and 3D airborne EM inversion through cross-gradient regularization and multi-grid efficiency. Issue 1 (1st December 2016)

• Record Type: Journal Article
• Authors: Scholl, C.; Hallinan, S.; Neumann, J.; Mulè, S.; Watts, M. D.
• Is Part Of: ASEG Extended Abstracts (Online). Volume 2016:Issue 1(2016)
• Page Start: 1
• Page End: 6
• Publication Date: 2016-12-01
• Subjects: Cross-Gradient -- Geosteered -- Inversion -- Electromagnetics -- Gradiometry; Prospecting -- Geophysical methods -- Periodicals; Prospecting -- Geophysical methods; Periodicals
• DOI: 10.1071/ASEG2016ab229
• Languages: English
• ISSNs: 2202-0586

Abstract

Abstract : With a goal of increasing the geological reliability of single and joint domain inversion, including those set in rugged terrain, we present an expanded scope for cross-gradient regularized inversion. The basic application covers the usual structural similarity objective - comparing the gradient fields of distinct property volumes derived from different geophysical domains - but a particular advantage comes when including gradients derived a priori, from geology or any ancillary property set, providing reference gradient control during single or joint inversions. In the first example, straightforward cross-gradient joint inversion of synthetic datasets of airborne EM (AEM) and airborne gravity-gradiometry (AGG) improves both the lateral and vertical definition of closely adjacent but distinct bodies. Two further AEM examples include surface and subsurface geology in the cross-gradient inversion; a) complex foothills setting, and b) buried massive sulphide. Both outputs demonstrate a marked improvement in interpretability over the standard smooth model approach.