free-air gravity anomaly
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free-air gravity anomaly[′frē ‚er ′grav·əd·ē ə‚näm·ə·lē]
A measure of the mass excesses and deficiencies within the earth; calculated as the difference between the measured gravity and the theoretical gravity at sea level and a free-air coefficient determined by the elevation of the measuring station. Also known as free-air anomaly.