Gravity prospecting involves the measurements of variations in the gravitational field of earth (g). Average value of 'g' at earth's surface is 9.80ms-2. Gravitational attraction depends upon density Surfaced underlying rocks. So, density is the physical parameter to which gravity surveys are sensitive
Newton's Universal law of gravitation:
The force of attraction between two bodies is directly proportional to the product of the two masses and inversely proportional to square of the distance between them.
where M and m are the masses of the two bodies, r the distance between them, G= 6.67x10-11Nm2kg-2 is the universal gravitational constant.
Land gravity surveys can be carried out by SCINTREX made Autograv CG-5.
- Regional survey:1-5Km station interval
- Semi regional survy : 500-1000m station interval.
- Detailed survey : 500-100 m station interval.