Russian Journal of Earth Sciences
Vol. 3, No. 4, October 2001
Modeling of seismo-electromagnetic phenomena
N. Gershenzon and G. Bambakidis
Department of Physics Wright State University, Dayton, Ohio U.S.A.
A model for seismo-electromagnetic (SEM) phenomena is described. The
electromagnetic signals generated by mechanical disturbances in the earth’s crust
have been calculated and compared with reported seismo-electromagnetic signals
(SEMS). The major known SEM phenomena, namely, tectonomagnetic
variations, electrotelluric anomalies, geomagnetic variations in the ultra-low
frequency range and electromagnetic emission in the radio frequency range, have
been considered. We have calculated the spectral densities associated with
various types of sources. The set of formulas necessary to calculate the detected
(filtered and averaged) electric and magnetic fields generated by mechanical
disturbances for a wide range of frequencies and at various distances from the
source are presented. Based on these formulas, we discuss the conditions under
which electrokinetic, piezomagnetic and piezoelectric effects could be
responsible for SEMS. A comparison of estimated values of SEMS with reported
field measurements leads to the conclusion that the sources of most anomalous
SEMS are relatively close to the detector. In other words, the source of the signal
is local, although the source of the mechanical disturbance which activates it, i.e.
the epicenter of an earthquake, may be far away. Recommendations for field
experiments (appropriate detector sitting, detector parameters and frequency
range) following from the model developed here are presented.
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