Magnetic methods, including magnetometry and microgravity surveys, are a popular, effective approach for near-surface metal detection – and GeoSonics/Vibra-Tech is synonymous with accuracy, quality and reliability in the field.
Magnetometry surveys are used to measure disturbances in the earth’s magnetic field generated by buried ferrous objects such as pipes, drums or a UST. Geologic structures such as igneous dikes or ore bodies can also cause local deviations in the earth’s magnetic field. The shape of the magnetic anomaly is an indication of the feature’s location and approximate depth of burial. The ease of data acquisition and low cost of such surveys make them ideal for delineating old landfills or buried debris, locating abandoned well heads, investigating the source of coal burns or acid mine drainage, detecting faults, and archaeological investigations.
Microgravity surveys are used to detect very small variations in the earth’s gravity field, such as those caused by near-surface features of engineering significance, including faults, buried river channels, fissures and solution cavities. Depth to bedrock and approximate fill thickness can also be measured if density values can be assumed for the material. The microgravity method is particularly useful in urban areas where other geophysical methods fail because of electrical interference or traffic noise.