1. n. [Geophysics]

In multichannel seismic acquisition, the common midpoint on a reflector, or the halfway point when a wave travels from a source to a reflector to a receiver that is shared by numerous locations if the reflector is flat-lying. Like common depth point, this term is commonly misused, because in the case of dipping layers, common reflection points do not exist.

See: channel,  dipping bed,  fold