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)
- Completeness of the ActivitySheet web page
For more information about the peer review process itself, please see http://serc.carleton.edu/NAGTWorkshops/review.html.
This page first made public: Oct 3, 2005
This material is replicated on a number of sites as part of the SERC Pedagogic Service Project
How to set up the demonstrationBuilding the actual earthquake machine can take from 2 to 5 hours, depending on availability of materials and basic construction skills. The apparatus consists of a wooden board 3-4 feet in length with a winch on one end. A pulley leads from the winch to the brick and is oriented so that the force acting on the brick has no vertical component. A strip of sandpaper down half of the length of the board increases friction. Earthquake Machine Diagram and Specs provides a list of materials and a diagram of the apparatus. Photo from USGS Earthquake Model.
How to do the demonstrationThe earthquake machine can be used in less than 5 minutes for a simple demonstration of how elastic energy is stored (as the winch is cranked) and then released in a sudden slip event. Cranking the winch slowly in silence is very effective, so students hear the grinding of brick upon sand paper as the slip event takes place. Alternatively, the machine can be used for a longer demonstration to illustrate the nature of recurrent slip and to explore alternative hypotheses of earthquake occurrence. Doing the demonstration in class outlines one way in which the demonstration can be used in class, along with tips for engaging students in the demonstration.
Ideas for discussing the earthquake demonstration in classMore ideas for class provides background material for topics of discussion related to the demonstration, including
- three hypotheses about earthquakes that can be tested, and
- background lecture material about the elastic rebound theory for the cause of earthquakes, and its relation to plate tectonics.
References and resources
- A U. S. Geological Survey website contains a complete description of how to build and use the earthquake machine.
- R. S. Stein, Parkfield's unfulfilled promise (News & Views), Nature, 419, pp. 257-258, September 19, 2002. A pdf for this article is available at the USGS website referred to above.
- The National Earthquake Information Center compiles and maintains an extensive, global seismic database on earthquake parameters and their effects.