Magnetics

Magnetic surveying measures the magnetic field strength and/or its components at a series of locations over an investigated area. The objective of magnetic surveying is delineating magnetic materials, mapping geological structures, or determining the basement depth.

Earth's magnetic field represented by a dipole at the Earth’s center

Typically, magnetic surveying using a magnetometer has been used for the delineation of magnetic anomalies. Magnetic anomalies is a function of the geometry of the body, direction of the Earth’s magnetic field, direction and content of the body’s magnetism, and orientation of the survey with respect to the Earth’s field. A gradiometer is the arrangement of two magnetometers that measures the difference of the magnetic field gradients. Either instrumentation setup has been employed in the past for magnetic anomaly detection and mapping.

Typical applications for the gravity profiling included:

• Locate buried ferrous materials such as steel well casings, tanks and pipes
• Locate and map buried waste sites and landfills
• Detect buried ordnance
• Map basement faults and geology
• Archeological investigations

Recent advancements in data collection include GPS controlled surveying.