An extension of the closed-form solution for the gravity curvature (Bullard B) correction in the marine and airborne cases

Abstract

Geoscience Australia recently revised the corrections applied to the Australian National Gravity Database (ANGD) and switched from applying the simple Bouguer correction to the observed gravity values in its database to applying the more accurate gravity curvature (Bullard B) correction. This change is a straightforward procedure in the case of land-based gravity surveys. However, due to the inherent non-linearity of the Bullard B correction, the original formula for the gravity curvature correction is not applicable to observed data from gravity surveys, which involve layers of different materials, as is the case in marine or airborne gravity surveys. Here we present an extension of the closed-form solution for the Bullard B correction, which allows its proper application in any gravity survey setting. In particular, we present formulae to correctly apply the Bullard B correction to observed gravity data from airborne and marine gravity surveys.