Conclusion

As has been shown, gravity gradiometry offers a significant increase in resolution and accuracy over conventional scalar gravimetry. Figure 2 illustrates this very convincingly, where we compare airborne gravity gradiometry data with conventional free air gravity data over a salt structure. This demonstrates the superior measurement of the gravitational field that a gradiometry survey provides, resulting in both improved spatial resolution and definition of geological features.

Gravity Gradiometry vs. Conventional Gravity
Figure 2: Example of a high resolution Airborne Gravity Gradiometry data set acquired over a salt province and a conventional gravity dataset. Note that the scales are different and the corresponding GGI data area is shown superimposed on the conventional gravity image. Blue anomalies denote areas of reduced mass and therefore salt, warm colours denote areas of increased mass and therefore clastics and carbonates.

To summarise, Gravity gradiometry instrumentation has four major advantages over conventional scalar gravimetry:

  • Increased signal bandwidth
  • Higher signal to noise
  • Ideally suited to high dynamic environments
  • Five independent measurements

The combination of these factors means that Gravity Gradient Imaging (GGI) delivers a more complete geologic picture over a wider bandwidth and with increased resolution.