Gravimetric prospecting basically aims at the detection and study of bodies and underground structures by means of the modifications that the presence of these produces in the terrestrial gravitational field, because of the differences of density between the different types of rocks.

It is another method that takes advantage of a natural Newtonian field, the gravitational, so it is not necessary to create it previously and the observations are to determine the value of gravity in a series of points (stations) that cover, with greater or less density, the study zone.

The mass of the earth's crust, in its first 5 km, is responsible for only 4.5 ten thousandths of the total terrestrial attraction (most of it is due to the mantle), so that the variations in the density of the rocks that constitute said Surface part of the court produce anomalies of the order of one millionth of the terrestrial gravitational field and even less. Therefore Gravimetric Prospecting requires the use of instruments of great sensitivity and precision (of the order of 10-8), since only bodies or structures can be detected when they differ in their density from the surrounding rocks (density contrast).

gravimetry

A gravimetric survey usually consists of the determination of the differences of gravity between a series of points called stations that are distributed approximately uniformly over the study area. The results obtained are compared with those corresponding to an ideal soil model with homogeneous density subsoil. The differences obtained in this comparative process, called reduction, are called gravimetric anomalies and they are the ones that serve as the basis for the detection and determination of disturbing bodies or structures.

In the example below we observe what kind of anomaly produces .............
Map of gravimetric anomalies

Gravimetry applications

The applications of this technique are multiple:

  • Search and prospection of mineral deposits (saline diapiros, sulphurs, oil and gas deposits, "screening" of anomalies found by other methods such as electromagnetic, etc.)
  • Basin undulations and detection of structures in the sedimentary layers, which are useful in Hydrogeology.
  • Location of underground cavities, well natural (karstic terrain) or artificial (archeology).
  • Tectonic and geological mapping studies.
  • Etc.

Contact us

C/ Beja 1 Local 1

28917 - Leganes (Madrid - Spain)


Phone: +34 917 500 904

Email: ocsa@ocsa-geofisica.com


"We seek efficient solutions for professionals"

"Our techniques such as seismic refraction, high resolution seismic reflection, electrical tomography or georadar reduce project costs"

"We carry out geophysical for large and small businesses"

Politica de calidad y medio ambiente
certificado iso-9001
certificado iso-14001