A small device implanted in the lunar surface during the deployment of the ASK to detect vibrations of the Moon from artificial and natural sources.

a small, cheap instrument for measuring ground motion

a device to transform seismic energy (movement) to an electrical voltage – voltage that is proportional to the velocity of the seismic wave motion.

A device used in surface seismic acquisition, both onshore and on the seabed offshore, that detects ground velocity produced by seismic waves and transforms the motion into electrical impulses. Geophones detect motion in only one direction. Conventional seismic surveys on land use one geophone per receiver location to detect motion in the vertical direction. Three mutually orthogonal geophones are typically used in combination to collect 3C seismic data. Hydrophones, unlike geophones, detect changes in pressure rather than motion.

A geophone is a device which converts ground movement (displacement) into voltage, which may be recorded at a recording station. The deviation of this measured voltage from the base line is called the seismic response and is analysed for structure of the earth.