1. n. [Geophysics]

The effect of the separation between receiver and source on the arrival time of a reflection that does not dip, abbreviated NMO. A reflection typically arrives first at the receiver nearest the source. The offset between the source and other receivers induces a delay in the arrival time of a reflection from a horizontal surface at depth. A plot of arrival times versus offset has a hyperbolic shape.

Alternate Form: normal moveout

2. n. [Geophysics]

The procedure in seismic processing that compensates for the effects of the separation between seismic sources and receivers in the case of a horizontal reflector.

Alternate Form: normal moveout