Magnetic surveying is a passive method based on the measurement of localised perturbations to the Earth's magnetic field caused by the presence of buried ferrous targets (e.g. pipes, cables, drums, military ordnance etc.).
Magnetic surveys can be conducted with a wide range of magnetometers, which can measure the amplitude of the field to within 0.01nT. Gradiometry surveys, which determine the vertical gradient of the magnetic field, are increasingly common in environmental/engineering site investigations as they are particularly sensitive to the near-surface.
Magnetic Surveying Applications
- Archeological studies
- Mapping underground storage tanks and buried drums
- Detecting piles and reinforced concrete
- Detection of underground pipes and other utilities
- Locating landfill boundaries
- Detection of buried infill
- Mineral exploration
- Geological studies
- Mapping land mines and unexploded ordnance