What is Gravity method?

Gravity techniques measure minute variations in the earth's gravity field. Based on these variations, subsurface density and thereby composition can be inferred. These variations can be determined by measuring the earth's gravity field at numerous stations along a traverse, and correcting the gravity data for elevation, tidal effects, topography, latitude, and instrument drift.

Typical applications of gravity surveying include:
*  Mapping bedrock topography,
*  Locating voids or cavities,
*  Formation or pluton boundaries,
*  Location of faults, buried river channels, and fissures,
*  Monitor aquifer storage change (using time lapse technique.