The artifacts are also similar in magnitude to the lateral smearing that occurs in 3D models when using relatively coarse 3D geometries. 3D experiments can be justified when a dense grid of shots and receivers is used or if a volume image, as opposed to a cross-sectional image, is required. Shot points indicated by white dots and receivers spaced at 1 km are located along each line. Dots are shot points. In all cases, the anomaly has been imaged at a greater depth and with a lower magnitude than the true anomaly.
White ellipse indicates position of true velocity anomaly.
Thick, short dashed line represents depth to the true reflector. Thin, solid line represents depth to the recovered reflector in the 3D models for the 3D geometries as labeled. Thin, long dashed line represents depth to the reflector from the 2D inversions. The PcP reflection points associated with each final model are superimposed on each plot. Contour interval is 1 km.