(n.) Geophysics. A phenomenon of relative seismic velocities of strata whereby a shallow layer or feature with a high seismic velocity (e. g. , a salt layer or salt dome, or a carbonate reef) surrounded by rock with a lower seismic velocity causes what appears to be a structural high beneath it. After such features are correctly converted from time to depth, the apparent structural high is generally reduced in magnitude. Ant: Push-Down. See: Depth Conversion, Salt Dome, Velocity Anomaly