Subduction Zone Earthquakes
This activity was selected for the On the Cutting Edge Reviewed Teaching Collection
This activity has received positive reviews in a peer review process involving five review categories. The five categories included in the process are
- Scientific Accuracy
- Alignment of Learning Goals, Activities, and Assessments
- Pedagogic Effectiveness
- Robustness (usability and dependability of all components)
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This page first made public: Apr 29, 2008
- The difference between earthquake focus and epicenter
- That the deepest earthquakes are farthest from the trench.
- That most earthquakes occur on only one side of the trench.
- The relationship between subduction angle to earthquake epicenters
- That there is no relationship between earthquake magnitude and earthquake position or depth.
Context for Use
- One legal-size (8.5 x 14) piece of paper labeled Oceanic Lithosphere" showing a trench at one end, a series of earthquake foci, and a depth scale along one edge. (See handout.) Earthquake magnitudes are denoted by size of the symbol and are categorized as small, medium, and large.
- One 8.5 x 11 piece of clear transparency film labeled "Continental Lithosphere".
- Two transparency markers (different colors).
Subduction Zone Earthquakes Templates (Acrobat (PDF) 85kB Apr29 08)
During a lecture, have the students hold the transparency level while allowing the paper to hang downwards at any angle. The paper represents the descending oceanic crust and the transparency represents the overriding plate. Students use the marker to plot the locations and magnitudes of each earthquake, and then use that information to answer instructor-led questions concerning the relationships between earthquake magnitude, position, and depth.
Teaching Notes and Tips
- If you have a personal response system, you can ask conceptest questions that focus on epicenter location or magnitude distribution. (See Reference and Resource section for conceptest questions that assess this model.)
- By walking around the class, the instructor can observe how well the groups comprehend the underlying concepts and ask individual students to explain their conceptual understanding.
- A short quiz could be given at the end of the class.
- Students could complete a worksheet containing questions about subduction zone earthquakes.
- Students could write a 'minute paper' explaining the distribution of subduction zone earthquakes.