This is a seismic section extracted from a 3-D seismic survey at approximately the same location as the 2-D seismic on the previous slide. Note the fault is much sharper, with amplitudes coming up to the fault and then stopping. This is a classic fluid seismic response. 2-D seismic data is collected along a line, and when migrated or focused in processing, it only has data along the line to improve the quality. 3-D seismic data is collected with many parallel lines with about the same line spacing as trace spacing. With 3-D, if there is energy out of the displayed cross-section, it is all available for the migration processing (or focusing).
(acqusition, 2-D processing, fault interpretation, reef interpretation, and siliclastic interpretation)