MAGNETIC FIELD NEAR THE OUTCROP OF AN ALMOST HORIZONTAL CONDUCTIVE SHEET

Abstract

The magnetic field components are studied near the outcrop of an almost horizontal (elongated) conductive sheet when an electric dipole lies far away from the outcrop but close to the sheet. The results have been applied to the case of the transmission of seismic electric signals (SES) by considering the current aspects on the orientation of the maximum principal stress with respect to the fault. Assuming that the latter orientation coincides with that of the emitting dipole source, it seems likely that the SES are accompanied by magnetic field variations with prominent BZ component. These variations become detectable near the outcrop only for strong earthquakes (with M>=6.5) at epicentral distances of the order of 100 km.