Fatiando a Terra Data: Bushveld, Southern Africa - Observed and preprocessed gravity

This dataset contains ground gravity observations over the area that comprises the Bushveld Igenous Complex in Southern Africa, including preprocessed gravity fields such as the gravity disturbance and the bouguer gravity disturbance (topography-free gravity disturbance). In addition, the dataset contains the heights of the observation points referenced on the WGS84 reference ellipsoid and over the mean sea-level (what can be considered to be the geoid). This dataset was built upon a portion of the Southern Africa gravity compilation available through NOAA NCEI.

Note: This is a processed and formatted version of the source dataset below. It's meant for use in documentation and tutorials of the Fatiando a Terra project. Please cite the original authors when using this dataset.

Changes made:

The original data were cropped to a region bounded by 25 and 32 degrees on longitude and -27 and -23 degrees on latitude.

Geometric observation heights were obtained by adding geoid heights to the original observation heights referenced on the mean sea-level. The geoid heights on each observation point were obtained by interpolation of the geoid available in doi: 10.5281/zenodo.5882205.

Gravity disturbances were computed by removing the normal gravity of the WGS84 ellipsoid computed through Boule.

Bouguer gravity disturbances were computed by forward modelling the topography using Harmonica starting from the topography grid provided in doi: 10.5281/zenodo.6481379 and using densities of 2670 kg/m³ above the ellipsoid and 1040 - 2670 kg/m³ below the ellipsoid.

Source: NOAA NCEI (gravity) and ETOPO1 (topography)

Source license: public domain (gravity) and public domain (topography)

Repository: https://github.com/fatiando-data/bushveld-gravity