USING GOOGLE EARTH TO INVESTIGATE PLATE TECTONICS AND THE BREAKUP OF PANGAEA

We have designed and implemented a Google Earth-based interface that allows users to explore the break up of the supercontinent of Pangaea over the past 250 million years. The animation is an excellent tool for visualizing how the present day continents have moved to their current locations, and it highlights salient features of modern plate tectonics. In addition to the standard Google Earth features, this animation has a variety of added functions including a slider bar to adjust the time period of the Earth back to 250Ma. Continents can be selected and deselected in order to best visualize the movement of a continent during the breakup of Pangaea. Users can view the movement of continents from any viewpoint, or can “fix” a continent to view the motion of other continents relative to the “fixed” one. Users can also toggle hotspot and mountain belt chains to view their respective locations through time. The animation was built using the custom web-based software MaRGEE (http://geode.net/margee/), which enables polygons (such as continents) to be moved around the Google Earth globe.

The Pangaea breakup animation is targeted for use by novice general education and geoscience students from high school to undergraduate levels. We have designed exercises to complement Physical Geology course modules on plate tectonics and continental drift, and use the animation as an inquiry-based tool to improve student comprehension of the breakup of Pangaea and global plate tectonics over the past 250 million years. An example exercise consists of 10 multiple-choice questions and 5 short answer questions; questions get progressively more difficult, and students are challenged to think logically and make scientific inferences for many tectonic concepts. Preliminary assessment results showed that the multiple-choice portion of the exercise was effective and well understood amongst the students tested. However, the short-answer section produced a much greater variation in students' answers. Assessment results also suggested short-term gains in understanding of plate tectonic processes; however, long-term results are inconclusive. More advanced exercises that make use of the Pangaea Breakup animation are under development.