Underground multielectrode sensor for identification of incoherent nonstationary electrical processes.

Abstract

In geophysical exploration and geomagnetic monitoring, the self-potential method examines slowly varying electric potentials measured across horizontally extended electrodes. Subsequently, electric methods were applied in earthquake precursor studies facing significant troubles such as the unknown source of precursory electric parameters changes and potential effects mainly of magneto-ionosphere origin. There is urgent request to update the mechanism explaining a promising number of observations since attempts to focus on stress and strain changes and fluid flow have not yet yielded useful results. Theoretical and experimental work has reinvestigated the conditions of how measurements should be made using a new class of sensor. The methodology relies on long-range couplings in the Earth's core - Earth's mantle - Earth's crust - ionosphere system evolving in an impulsive manner globally in space and time. The aim of proposed approach consists in the detection of electrical contrasts within the vertical and lateral zones subsurface (channels and layers). Proton migration develops DC and AC electromotive force registered as electrical intensity across arrays of vertical sequences of subsurface electrodes. Field measurements present observational characteristics of measured time series using the multielectrode method. Clearly visible contrasts above slow-changing signals even without post-processing noise reduction procedures are emphasized. Main results presented are detailed observations of incoherent occurrence of underground electrical signals which were followed by major earthquakes occurred at various distance.