Subducting Plate Graphs
Some modifications of target audience
Type and level of course in which you would use this activity:
We've used this in workshops on plate tectonics for middle school and high school teachers. This is a modification of “Real Evidence of a Subducting Plate” by McLelland and Martin, created for use in high school classes. The activity can be used in undergraduate introductory courses, as well as for pre-service teachers.
Skills and concepts that students should have mastered before beginning the activity:
The students should be familiar with the concepts of plate
tectonics, subduction, and the relationship between subduction and earthquakes.
How the activity is situated in its course
This is part of a sequence of activities, starting with Dale Sawyer's Discovering Plate Boundaries, and followed up with Hot Spot Motion.
The students will graph earthquakes along the west coast of South America to create a graphic outline of the shape of the subducting plate. In a possible extension, students could use the IRIS Earthquake Browser (www.iris.edu/ieb/) to generate their own data, and use a program like Excel to create the graph.
Students should be able to describe the relationship between the earthquakes and the subducting plate along the coast of South America. They should be able to suggest possible explanations for the differences in the slopes of the graphs at different latitudes. They should also be able to suggest possible error sources.
Supporting references and/or URLs
Students may be interested in comparing their graph to the modeling data of subducting plates at http://rses.anu.edu.au/seismology/projects/RUM/slabs/slabs.html.