Geophysical electromagnetics: imaging the subsurface from shallow to deep


Locating critical minerals, monitoring geologic storage of CO2, managing aquifers, remediating land, and monitoring changes to permafrost are just a few examples of important geoscientific problems that require us to characterize the subsurface. Much like how medical data such as an MRI or X-rays are used for non-invasive imaging, geophysical surveys collect data that are sensitive to the physical properties of the subsurface. In particular, electrical conductivity can be a diagnostic physical property for many geoscientific applications and this motivates the use of electrical and electromagnetic (EM) geophysical methods in a variety of applications. In this talk, I will show examples of the use of EM across a range of scales, including applications in mineral exploration, carbon capture and storage, groundwater, and detecting and classifying unexploded ordnance. These examples illustrate the value of numerical simulations to understand physical responses, the role of inversions for estimating models of the subsurface, and new research avenues for combining machine learning with physics-driven approaches.