GRAVIMETRY

The gravity method is a passive, non-destructive geophysical technique involving the precise measurement of the Earth’s gravitational field at specific locations on the Earth’s surface. The careful processing and imaging of these measurements provides the detection of  gravity changes due to lateral variation in subsurface density. The method can be used to detect density variation on all scales; from microgravity surveying for natural or man-made voids to prospect scale surveying for ore deposits, to space-borne surveying to characterise the shape of the Earth’s core. Geo Alps specialises in ground based gravity surveying from microgravity (10s of m) to regional (100s of km) scales. The gravity technique is based on measuring localised variations in the Earth’s gravitational field which are caused by materials of different densities. The presence of an anomalously high (or low) density body in the subsurface causes a localised high (or low) anomaly in the measured gravitational field. The gravity effects described can be extremely small, however modern instrumentation and exhaustive data processing techniques enable detection of both geological and artificial structures or voids. The Gravity method  is used by Geo Alps while working in difficult settings where other more rapid and economical methods cannot be employed. It is a method capable of performing in environmentally sensitive areas such as inside buildings and parking garages. Most of the sites requiring gravity surveys, often as the only resort, involve mapping voids, underground wash-outs, sink holes and other cavities