The science behind Plate Tectonics
Plate tectonics is a quantitative, robust and testable, geologic model describing the surface motions of Earth's outer skin. It is based on real data and assumptions, and built using the scientific method. New space geodesy data provide important quantitative (and independent) tests of this model. In general, these new data show a close match to model predictions, and suggest that plate motion is steady and uniform over millions of years. Active research continues to refine the model and to better our understanding of plate motion and tectonics. The exercise presented here aims to help students experience the process of doing science and to understand the science underlying the plate tectonic theory.
Key words: plate tectonics, global plate motion models, assumptions, geologic data (spreading rates, transform fault azimuths, earthquake slip vectors), space geodesy tests.
Geared toward undergraduate non-majors general education courses, and introductory-level majors courses. Also serves as a window into the historic (discovery) and recent geological literature on plate tectonics for instructors who have not had coverage of this material in their own training, or have not been able to keep up-to-date with it.
Skills and concepts that students must have mastered
Reading, writing, some basic math, and knowledge of how to access library materials.
How the activity is situated in the course
This can be used as a stand-alone exercise. It works well to introduce plate tectonics, or as a concrete example of how inductive and deductive thinking work together to create a "circle of science".
Content/concepts goals for this activity
This exercise aims to help students experience the process of doing science and to understand the science underlying the plate tectonic theory.
Higher order thinking skills goals for this activity
The exercise asks students to take a thorough and critical look at the science behind one of geology's major paradigms. Much of this science is typically glossed over in introductory courses, which can leave students to develop misconceptions about how plate tectonics works and how the theory developed and was tested.
Other skills goals for this activity
Critically evaluation of selected peer-review papers with specific guiding questions.
Description and Teaching Materials
Students read a long well-written narrative that summarizes how all of the component pieces (assumptions, data, tests, etc.) fit together to make up the theory of plate tectonics. A number of questions follow, from which instructors can pick and choose, to emphasize which particular aspects of "the science behind plate tectonics" they want students to get.
The Science Behind Plate Tectonics (Microsoft Word 2.2MB May30 12)
Teaching Notes and Tips
I find it best to assign the reading before attempting to lecture about this material. I talk about the material with the students, then have them work on the questions independently. We then go over their calculations and answers in class as a group.
I mark-up and grade the answers to the questions that students turn in.
References and Resources