Creating Shaded Relief

TIPS & TRICKS
Creating Shaded Relief

Sometimes, a surface with low overall relief can appear quite bland in map view. These tips and tricks cover several options that can be used separately or together to increase surface relief in the map view.

When a horizon does not show a clear colour definition in the map view, the first change to make is the Min/Max limits of the horizon since the default Z range is usually several thousand milliseconds or meters.

  1. Click the spanner icon next to Property.
  2. Turn off the Use min and max from class settings option.
  3. Click Adjust.

The next change to make is the colour bar itself, as the default colour is a faded pastel range.

  1. Click on the colour icon in the Horizon Settings window to open the Time (TWT) class settings.
  2. Select a richer colour bar such as the Rainbow_Classic.ducolbar instead. To do this, right-click in the colour bar box, select Load, and select the desired colour bar.
  3. Consider setting your default class settings to match your data set while viewing the class settings. The default time range is 0-10000. Try 0-4000 for conventional data or 0-200 for high-res shallow data.

Try displaying with and without contours. Refer to Contouring (Map View) for more details.

Dense contours provide an instant shaded relief effect. The following is a 5ms contour for a conventional dataset:

Tip: Turn off the labels for a cleaner view.

You can create a shaded map using surface groups using the following steps:

  1. Change the attribute to Dip Pseudo-Angle.
  2. Click the spanner icon, and change the dip class to a low angle such as 0-50 for conventional or 0-0.5 for high res data, and make the colour black-white.
  3. Set the transparency to 50%.
  4. Save as a custom property.
  1. Create a surface group.
  2. Add the seabed horizon twice, and change the top attribute to the dip attribute.

Review the resulting shaded surface.

Optionally, add contours and use the mixed attribute colour range settings to adjust to your dataset.

Summary

Default settings are designed to cover a large range of data displays, but some datasets will need adjustments to optimise or enhance the display. Using colours, Z ranges, contours, and dip attributes, you can transform a plain map into an enhanced map as depicted below: