Gravimetric fluctuation

A gravimetric fluctuation is a localized and nonlinear variation in gravimetric fields and in the concentration of graviton subatomic particles.

On Stardate 43625.2, the sensors of the USS Enterprise (NCC-1701-D) picked up unusual gravimetric fluctuations, like that of a temporal displacement vortex, but there was no discernible event horizon, center or outer edge. Also, navigational subsystems were unable to give coordinates on the object. 

In fact, this event occurred when the starship USS Enterprise'' (NCC-1701-C), lost for 22 years, came through a temporal rift. After the return of the Enterprise-C to their own timeline, everyone was back at their normal stations and left no direct evidence of the temporal upheaval.''

Gravimetrische Fluktuation