Different subsurface materials have different bulk densities. In microgravity surveying, areas of contrasting density are located by collecting surface measurements of the variation in the Earth’s gravitational field.
A gravity meter is a highly sensitive spring balance. When positioned above a dense material it records the acceleration due to gravity (g) as a relative high (a positive gravity anomaly). When positioned above a low density material (e.g. an air filled cavity) the gravity meter records a relative gravity low (or negative gravity anomaly).
Microgravity Surveying Applications
- Cavity detection (including bomb shelters, hidden tunnels/adits, old mine workings, sinkholes and dissolution features)
- Mineral exploration
- Density determination
- Grouting investigations
- Shallow pipe and sewer detection
As part of RSK's one stop solution, we have the capability to undertake follow up intrusive investigations utilising dynamic probe testing to verify the findings of gravity survey.