New Publication: Sharper Boundaries in 3D Electromagnetic Inversion
New research by Ming Zhang, Colin G. Farquharson, and Eric Attias, published in Geophysics, introduces a three-dimensional electromagnetic (EM) inversion method designed to better resolve geological boundaries.
Conventional smoothness-regularized inversion can blur sharp resistivity contrasts. The new approach incorporates EM field-gradient information into a Gauss-Newton inversion framework, using it to adjust regularization across the model. This strengthens boundary definition while maintaining smoothness and stability within homogeneous regions.
Two synthetic tests demonstrate more accurate resistivity models and clearer anomaly boundaries than standard Occam inversion, with comparable computational cost in the cases studied. One test uses a realistic synthetic model previously adjusted to fit field data.
The study shows how information contained in EM field gradients can improve subsurface imaging and help resolve fine-scale geological features.
Well done, Ming and team!
Read the paper: "Three-dimensional electromagnetic inversion with enhanced boundary resolution via field gradient constraints."
Geophysics, 91(5), E231-E246 (2026).
