Faulty Movement
Students are introduced to faults in the context of plate tectonics. They learn about different kinds of faults and their relationship to earthquakes. Student pairs create cardboard models of the three different types of faults—transcurrent, normal and reverse—as they learn about how earthquakes are formed and impact the structure of the Earth's crust.
Figure 1. A portion of the San Andreas Fault in California.Copyright Robert E. Wallace, U.S. Geological Survey http://pubs.usgs.gov/gip/earthq3/
Engineers study faults and the location of fault lines when they design structures so that they remain secure during earthquakes and fault activity. Engineers must understand fault types and how fast the plates are moving in order to predict the resulting type of land formation, such as a hill or valley. Engineers also consider the forces of the Earth and fault lines when designing roads, airports, dams, sewage systems and methods to obtain and filter drinking water so as to reduce the likelihood of damage occurring to these structures. Engineers also design seismometers, the sensitive equipment that measures ground motion generated by earthquakes and volcanic eruptions.
After this activity, students should be able to:
- Explain the concepts of plate tectonics and continental drift.
- Describe the three main types of faults: transcurrent, normal and reverse.
- Explain that earthquakes and volcanoes occur along the boundaries of crustal plates.
- Explain why engineers need to learn about the Earth's structure.
- Write as a means of applying, analyzing and synthesizing new information.