Can Subsurface Water Flow be Sensed Magnetically? Results from Electrokinetic Volcano Simulations

Friedel, S.
FEMLAB GmbH, Zürich

Today, geophysical exploration can provide information on the interior of volcanoes even before the edifice is mechanically destroyed by measuring physical fields at the surface and interpreting them with the help of sophisticated modeling techniques. An especially interesting method to map and monitor active volcanic zones is the observation of electromagnetic fields.

Electrical voltages can be caused when fluids — such as hydrothermal liquids, vapour or infiltrated rain water — flow through porous rock. Understanding this effect and using it for the investigation of structures and improving the prediction of volcanic activity relies heavily on numerical simulations.

This study describes numerical experiments investigating the conditions that are necessary to produce measurable quasi-static electric and magnetic signals by hydraulic flow in volcanoes.