1. n. [Geophysics]

The difference between the actual value of gravity measured at a location and the value predicted by a particular Earth model. Gravity anomalies are usually determined by adjusting the known value of (absolute) gravity at a reference station by Bouguer, free-air or other corrections and subtracting the final predicted value from the measurement. (A different description is that the various corrections are subtracted from the data to reduce it to the reference level. Both interpretations are valid provided it is remembered that the resulting gravity anomaly can be caused by density anomalies—i.e., differences in density between Earth and the theoretical model—that can lie anywhere either above or below the reference level.)

See: anomaly,  Bouguer correction,  free-air correction,  gravity