Mapping geological faults using image processing techniques applied to hill-shaded digital elevation models

Image processing techniques have previously been used to extract lineaments from aerial photographs and satellite images as a means for identifying linear surface traces of planar geologic structures such as faults and fractures. A major limitation of aerial photographs is their dependence on natural east-west solar illumination paths which highlight north-south linear features, perpendicular to the solar illumination. Hill-shaded digital elevation models (DEMs) are an alternative source for topographic imagery. The advantage of hill-shaded imagery is the freedom to select illumination from any angle. We present a procedure for extracting lineaments from hill-shaded DEMs and make comparisons of extracted lineaments to mapped faults from the Saline Range, California, and Yucca Mountain, Nevada. Results of these comparisons illustrate the effectiveness of extracting lineaments from hill-shaded DEMs.