Geological analyses of northern Wasatch Range, Utah digital elevation models

The Wasatch mountain range in north central Utah is part of the Intermountain Seismic Belt of the interior of the western U.S. and separates three distinct physiographic provinces: the Basin and Range, the Middle-Rocky Mountain, and the Colorado Plateau. The 343 kilometer long seismically active Wasatch normal fault in Utah has 6 to 10 distinct segments, an average displacement per rupture event of 2.0 meters, and a recurrence interval for large earthquakes (greater than 7.0) of once every 220 to 666 years. Studies of the Lost River fault suggest segment boundaries can influence rupture direction and propagation of large earthquakes.; Linear and curvi-linear patterns, which may represent features in topography created by tectonic and other processes, have been identified in 1:250,000 scale digital elevation models (DEMs) of the Wasatch range between Ogden and Salt Lake City, Utah, using a Geographic Information System (GIS). These patterns match known trends of major fault and fracture systems in the area. Directional filters used on the Ogden 1:24,000 scale DEM have produced patterns and trends similar to those produced by the GIS methods. The location and three dimensional orientation of faults, fractures, range front scarps, and faceted spurs have been found in the Ogden, Utah, 1:24,000 scale DEM using valley-bottom, ridge-top, slope-gradient, and slope-break detection methods. The slope-break detection method has identified range front scarps, Pleistocene Lake Bonneville shorelines, and well defined drainage patterns along the Wasatch front in 1:24,000 scale DEMs near Ogden and Draper, Utah. Image plots and stereonets are used to identify and quantify patterns and trends expressed on 1:24,000 and 1:250,000 scale DEM topography and correlate them with known geological structures in the northern Wasatch range of Utah.