abstract A relation is derived for correcting dT/dΔ for a single dipping interface under a seismic array: ( d T d Δ ) = ( δ T δ Δ ) ′ sin ( Ω − ω ′ ) sin ( Ω − ω ) . The formula depends only on the azimuth angles: ω is the computed azimuth, ω′ is the observed azimuth, Ω is the azimuth of the normal to the tilted interface, and (δT/δΔ)′ is the observed quantity. The relation is explicitly independent of the dip and the velocities of the media on either side of the interface.