GSA Penrose Conference
Google Earth: Visualizing the Possibilities for Geoscience Education and Research


Using Google Earth: From Teaching Geologic Map Interpretation to Conducting Research in the Western Desert of Egypt
Barbara J. Tewksbury1

(1) Department of Geosciences at Hamilton College, in Clinton, NY


The interactive 3D terrain viewing capability of Google Earth makes it a terrific resource for teaching geologic map interpretation. I have developed a successful approach where students start by doing their own geologic mapping in Google Earth before they know anything about strike, dip, or types of contacts. Being able to tilt and view from any direction allows students to make their own geologic maps successfully and to visualize the correlation between real world bedrock geology and 2D maps. The tilt and fly-through views also help students to see directly which way contacts are inclined and to successfully sketch topographic profiles and cross sections. While many instructors start with horizontal contacts because they seem simpler and don’t require defining strike and dip, I start with inclined contacts because they are actually easier for students to “see” in Google Earth and allow derivation of the concepts of dip (first) and then strike from direct visualization in Google Earth. This approach, which emphasizes visualization rather than memorization of patterns and rules, is applicable in both introductory geology and structural geology.

High resolution imagery in Google Earth not only provides an educational platform for teaching about bedrock structures but also, in some parts of the world, enables research in largely inaccessible areas. Over the last two years, I have initiated several research projects in the remote Western Desert of Egypt where high resolution Google Earth imagery has revealed extraordinary and largely unstudied fold and fault structures exposed over a distance of nearly 600 km between about 23.0° and 27.7° N. Lack of previous recognition of most of these structures can be attributed in part to the fact that most of the exposures lie in extremely remote areas, in part to the fact that they are enigmatic at Landsat resolutions, and in part to the fact that many are subtle structures that are difficult to see from the ground. They are crystal clear in Google Earth, and the complete lack of vegetative cover allows detailed maps to be made over huge areas that can then drive targeted field research in accessible portions of the region.

In December 2010, we had the opportunity to test our mapping of these structures in an area north of Kharga Oasis. Google Earth was absolutely critical to the success of our work. We mapped structures and established stratigraphy ahead of time on large scale, high resolution printouts from Google Earth Pro, which enabled us to target specific areas for field checking to maximize the small amount of time we had in the field. We took the printouts into the field with us marked with lat/lons for the critical areas, and we quickly discovered why these structures had never been mapped before. Had we not known from the Google Earth images that the structures were there, we would never have even seen them from the ground. And even though we knew the structures were there, had we not had the printouts, the lat/lons, and a GPS unit, we would never have found them on the ground.

Websites:
Links to the Egypt research: http://people.hamilton.edu/btewksbu/
The approach to teaching geologic map interpretation: http://serc.carleton.edu/NAGTWorkshops/structure/approach.html
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