A critical discussion of the electromagnetic radiation (EMR) method to determine stress orientations within the crust

摘要: Abstract. In recent years, the electromagnetic radiation (EMR) method has been used to detect faults and determine main horizontal stress directions from variations in intensities directional properties of emissions, which are assumed be generated during micro-cracking. Based on a large data set taken an area about 250 000 km2 Northern Germany, Denmark, southern Sweden with repeated measurements at one location time span 1.5 yr, was systematically tested. Reproducible observations temporary changes signal patterns, as well strongly concentric spatial pattern magnetic component EMR point very low frequency (VLF) transmitters source hence raise serious concerns applicability crustal stresses. We conclude that method, its current stage development, does not allow determination directions.