6533b86cfe1ef96bd12c80d3
RESEARCH PRODUCT
A critical discussion of the electromagnetic radiation (EMR) method to determine stress orientations within the crust
Axel VollbrechtU. KelkaM BockMichael KrumbholzMichael KrumbholzSteffi BurchardtSteffi Burchardtsubject
010504 meteorology & atmospheric sciencesStratigraphySoil Science010502 geochemistry & geophysicsSignalElectromagnetic radiation01 natural sciencesStress (mechanics)03 medical and health scienceslcsh:StratigraphyGeochemistry and PetrologyPoint (geometry)Very low frequencyEarth-Surface Processeslcsh:QE640-699030304 developmental biology0105 earth and related environmental sciences0303 health scienceslcsh:QE1-996.5Geovetenskap och miljövetenskapPaleontologyCrustGeologyData setlcsh:GeologyGeophysicsCommon spatial patternGeologiEarth and Related Environmental SciencesSeismologyGeologydescription
Abstract. In recent years, the electromagnetic radiation (EMR) method has been used to detect faults and to determine main horizontal stress directions from variations in intensities and directional properties of electromagnetic emissions, which are assumed to be generated during micro-cracking. Based on a large data set taken from an area of about 250 000 km2 in Northern Germany, Denmark, and southern Sweden with repeated measurements at one location during a time span of about 1.5 yr, the method was systematically tested. Reproducible observations of temporary changes in the signal patterns, as well as a strongly concentric spatial pattern of the main directions of the magnetic component of the EMR point to very low frequency (VLF) transmitters as the main source and hence raise serious concerns about the applicability of the method to determine recent crustal stresses. We conclude that the EMR method, at its current stage of development, does not allow determination of the main horizontal stress directions.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-01-01 |