Аннотация:Electromagnetic perturbations of currents generated during microfracture opening are studied in this paper. The currents are caused by a movement of the Earth's conducting layers in the geomagnetic field. The main idea of the paper is that, under certain conditions, effective magnetic moments of all currents related to the individual microfractures turn out to have the same direction, regardless of a fracture's spatial orientation, This circumstance naturally provides a maximum electromagnetic effect.