Electrokinetic geophysics — a review

Electrokinetic phenomena occur in porous rocks and include streaming potential, electro-osmotic and electrophoretic effects. Geophysical techniques can generate acoustic body waves that stimulate electrokinetic coupling at subsurface boundaries. The electromagnetic effects generated are observed using surface electric field sensors. Improved methodologies, aided by recent modelling of the coupled acoustic and electromagnetic wave equations, are re-exploring electrokinetic behaviour in the near surface. The methodologies are aimed at providing geophysical tools that may characterize environmentally sensitive parameters such as the fluid content, the fluid geochemistry and the microstructural fabric of the subsurface.