Gravimeters are devices designed to measure slow changes in gravity at or near the surface of the earth. The largest such variations are due to the tidal forces from the sun and the moon and the elastic response of the earth to them. Other causes include changes in atmospheric pressure, changes in ground water, vertical crustal motion, and movement of magma beneath the surface. The superconducting gravimeter provides greater long-term stability than can be obtained by other instruments and consequently allows measurement of phenomena that have not been previously observable. I will describe the construction and function of the superconducting gravimeter and some of the physical and geophysical problems to which it has been applied.

ANL Physics Division Colloquium Schedule