Earthquakes that occur within plate boundaries, called intraplate earthquakes, have long intrigued both students and educators. Classroom exploration of U.S. seismicity and hazards maps inevitably generates numerous questions from the learners regarding the New Madrid Seismic Zone (NMSZ). Unfortunately, many earth science teachers are not prepared to exploit this interest by discussing the ongoing debate regarding the seismic hazard in the region. This intreractive demonstration is designed to empower teachers, through the use of a physical model, the Booby Trap (TM), to explore both the possible mechanics of intraplate quakes and what this may mean for hazard models in the region.
Students will be able to
Using a block-and-sandpaper model, students collaborate in small groups to investigate how energy is stored elastically in rocks and released suddenly as an earthquake (the earthquake cycle). This activity emphasizes the role of mechanical models in understanding and testing ideas in science.
Animation of the single-block "Earthquake Machine", a mechanical model of the earthquake process using a wood block, sandpaper, and rubber bands. This model shows how "Forces, Faults, and Friction" interact as elastic energy is slowly stored when the rubber back stretches and then is rapidly released as the block jerks during an "earthquake".
Graphing time vs. distance using the classic block-and-sandpaper "earthquake machine"
Graphing time vs. strain using the classic block-and-sandpaper "earthquake machine"