GSA Penrose Conference
Google Earth: Visualizing the Possibilities for Geoscience Education and Research
Integrating Geologic Maps and Cross Sections in an Interactive 3-D Environment
(1) Department of Geosciences, Williams College, Williamstown, MA, USA 01267
Traditional geologic maps and cross sections are common, time-tested, and effective ways to portray the structure of a region, but are best appreciated by experienced geologists. Textbooks integrate maps and cross sections into static perspective block diagrams to help students visualize basic concepts in structural geology. The inherent power of block diagrams, however, is dramatically increased by software that can create interactive 3-D models of a region, which can be rotated, panned, and zoomed by the user. The best way to create virtual block diagrams is to combine the individual strengths of dedicated GIS software with Google SketchUp and Earth, and merge the results into a single 3-D model.
Effective 3-D models drape geologic maps on topography and show how the maps and cross-sections connect at the topographic surface. Creating models in segments gives the user flexibility to ‘turn off’ individual portions of the surface to sequentially reveal multiple cross-sections. Such models help students and non-specialists visualize geologic structures, and provide geologists with a valuable tool for assessing the validity of geologic interpretations. It is even possible to construct cross sections in a 3-D environment using SketchUp.
Even the best 3-D virtual block diagrams can be challenging for students to interpret and understand. Basic concepts such as bedding and strike and dip are unfamiliar to most non-geologists. SketchUp can be used to add visual cues to maps and show the intersection of unconformities, faults, and plunging folds with the topographic surface. These accurately constructed and located models of geologic structures can be exported to Google Earth, and are particularly effective for showing how bedrock geology affects the topography of a region.