The Influence of Anomalous Magnetic Permeability on MT/MV Responses Observed at the Voronezh Massif Near Intensive Magnetic Anomalies

摘要

The basic medium model considered in magnetotelluric (MT) and magnetovariational (MV) studies assumes the magnetic permeability being fixed everywhere at the free space level. However, this assumption can cause distortions in the MT sounding results near strong permanent magnetic field anomalies. We made 2D modelling of such distortions arising along the KIR-OVOGRAD project MT/MV sounding profiles at the western slope of the Voronezh Massif. Minor changes are seen in modelled data for TM mode components. At the same time, the MV anomalies in TE mode are decreasing with the increase of magnetic permeability within upper crustal magnetic blocks. This effect may cause the decrease (or even break) of deeper low crustal conductive anomalies just below strongly magnetic bodies.