Clarification of the geophysical definition of a gravity field

Abstract Several dictionaries, including the Encyclopedic Dictionary of Exploration Geophysics (Sheriff, 2002), define gravity field as a region or a space in which a gravitational effect exists, or gravitational forces can be detected. This definition differs significantly from others in the geophysical literature, which often define the gravity field as the gravitational force at any point within a region or a space. Defining the gravity field as a region or a space is misleading. It is not a standard physics definition of a field, and thus it confuses the field itself with the region over which the field exists. Our proposed definition for the gravity field is as follows: a gravitational force or gravity exerted on a unit mass at a point in a space or on the surface of the earth or its vicinity. Thus, the gravity field is defined as a force or a force field rather than a region or a space. A measurement of gravity fields should be made in a region or a space in which gravity fields exist.