1. n. [Geophysics]

A type of vertical seismic profile in which the source is moved to progressively farther offset at the surface and receivers are held in a fixed location, effectively providing a mini 2D seismic line that can be of higher resolution than surface seismic data and provides more continuous coverage than an offset VSP. 3D walkaways, using a surface grid of source positions, provide 3D images in areas where the surface seismic data do not provide an adequate image due to near-surface effects or surface obstructions. Walkaway VSPs in which the receivers are placed just above the reservoir are gaining acceptance as a tool to quantify seismic attributes and calibrate surface seismic data.

See related terms: offset,  receiver,  source,  vertical seismic profile