1. n. [Geophysics]
The difference in the arrival times or traveltimes of a reflected wave measured by receivers at two different offset locations. Normal moveout (NMO) is moveout caused by the separation between a source and a receiver in the case of a flat reflector. Dip moveout (DMO) occurs as an effect in addition to NMO when reflectors dip. Problems that require static corrections can also produce moveout.