SM3.10/EMRP2.10/ERE5.5Seismo-electromagnetic conversions: observations, theory and modelling (co-organized)
Conversions from seismic to electromagnetic energy occurring in porous saturated media have been observed since the 1930’s and were rapidly identified as being of electrokinetic nature. However the subject has recently gained new perspective as the theory explained this transient effect to result from the coupling of Biot’s and Maxwell’s equations with regard to the electrical double layer. The seismoelectromagnetic effect, including both seismoelectric and seismomagnetic phenomena, can be divided into two aspects:
- First, a coseismic electromagnetic signal highly similar to the generated seismic wave and travelling with it;
- Second, an evanescent electromagnetic dipole resulting from the conversion of mechanical into electromagnetic energy at an interface marking a discontinuity in rock, pore or fluids properties.
A reversed conversion mechanism from electromagnetic into mechanical energy is observed in electroseismics. In this case, an active electrical field passing an interface releases a mechanical source mechanism that generates seismic waves. Both methods are expected to eventually combine the spatial resolution of seismics with the sensitivity of electrical methods to fluid flow. In this regard, it could ultimately offer a direct access to various hydraulic parameters ranging from porosity to hydraulic conductivity or salinity.
In this session, we welcome contributions embracing seismoelectrics, seismomagnetism, electroseismics or electrokinetics at high and low frequencies. We invite contributors to present their works dealing with experimental observation of those phenomena at field or lab scale. Special attention will be paid to the either saturation- or frequency-dependent investigation of these effects. Innovations in data acquisition as well as improvements in data processing and filtering will be addressed. Further contributions tackling theoretical developments and modelling aspects are utterly expected, with special focus on forward 2D- and 3D-modelling.