What is magnetometry?
Geomagnetic field anomalies are caused by the presence of rock types and artificial objects with contrasting magnetic properties.
Magnetometry is used, for example, to detect underground objects with different magnetic properties (with ferromagnetic materials, mainly iron and steel), to map lithological types with different magnetic susceptibility, etc. Influence of field time variations, regional anomalies and other disturbing effects (utilities, structures, etc.) can be minimized by so-called gradient measurement (gradiometers).
For the localization of metal underground objects, magnetic measurements are combined with measurements with metal detectors, which are suitable for finding shallowly stored or smaller mainly metal objects.
Kappametry and the DEMP method
Kappametry is useful for the differentiation of rock types (especially on samples), which can be used to quickly determine the magnetic properties (magnetic susceptibility kappa). The measured data are processed in the form of maps of graphs of measured data or in the form of maps of isolines of measured values. For clarity during the presentation one can use the 3D display.
The device for electromagnetic dipole profiling (GEM-2) provides both information on the geoelectric properties of the environment and on the susceptibility of rocks. It thus combines the geoelectric method with magnetometric survey.
This procedure is used by G IMPULS especially when surveying old landfills.