The migrated and depth-converted sections are visualized as monochrome variable-area plots (with or without wiggle lines) and envelope sections. These two can also be overlaid with one another, producing a “two-attribute” picture. Two-attribute representation is typically used for near-surface data.
The variable-area plot is the classical way to visualize traces. The area between the baseline and the trace is filled in black whenever the polarity of the trace is positive. The trace itself (“the wiggle”) may or may not be drawn. The data is clipped at the 98th percentile before plotting to bring out the smallest features.
In envelope sections, each trace is replaced by the instantaneous amplitude (envelope) of the corresponding analytic trace, and the data is smoothed by averaging it to e.g. a 500-meter resolution. The data is represented as a seismic contour plot, with double linear interpolation performed between sample points. The colour map is a logarithmic greyscale or a colour gradient.