Loading
Nigeria's free digital learning hub. Videos, lecture notes, practice questions and leaderboards aligned with CCMAS, NBTE, NCCE, WAEC, NECO, IJMB and JAMB curricula.
Electromagnetic and magnetotelluric methods are advanced geophysical techniques used in earth investigations to probe subsurface conductivity variations. Electromagnetic methods rely on generating artificial electromagnetic fields and measuring their response as they interact with geological formations, making them effective for shallow to intermediate depth studies such as mineral exploration, groundwater mapping, and environmental assessments. Magnetotelluric (MT) methods, on the other hand, utilize naturally occurring variations in the earth’s magnetic and electric fields caused by solar and atmospheric activity. By recording these signals over a wide frequency range, MT surveys can reveal conductivity structures from near-surface layers down to the deep crust and mantle. Together, these methods provide complementary insights: electromagnetic surveys excel in high-resolution imaging of localized targets, while magnetotellurics are invaluable for regional-scale investigations of tectonic settings, geothermal reservoirs, and deep resource exploration. Their integration allows geoscientists to build comprehensive models of the earth’s subsurface, bridging shallow exploration with deep geodynamic processes.
This lecture is part of GPH 312 ELECTRICAL AND ELECTROMAGNETIC PROSPECTING METHODS in the Geophysics department. The course has 30 recorded lectures across 10 series, all free to watch. Read or download the GPH 312 lecture note to study alongside the video.