Research news on magnetotelluric surveying

Magnetotelluric surveying is a passive geophysical method that measures naturally occurring, time-varying electric and magnetic fields at the Earth’s surface to infer subsurface electrical resistivity structure. It exploits a broad spectrum of natural source signals, from ionospheric and magnetospheric variations to lightning, and uses their frequency-dependent penetration depths to image structures from near-surface to mantle scales. Field measurements of orthogonal electric and magnetic field components are processed to obtain impedance tensors and tipper functions, which are then inverted using 1D, 2D, or 3D electromagnetic inversion algorithms to produce resistivity models relevant to tectonics, geothermal systems, mineral exploration, and crust–mantle studies.