Earthquake Machine (Activity 2 of 2)


Investigating an earthquake’s frequency and magnitude

The Earthquake Machine is a simple model that demonstrates earthquake mechanics. The parts of the Earthquake Machine represent the elements of an active fault. Earthquake Machine (Activity 1 of 2) introduced the model and used a qualitative approach to observe the stick-slip fault behavior that leads to earthquakes. In this second activity, learners take quantitative measurements to explore earthquake frequency and magnitude.

Why is it important to learn about the unpredictable behavior of earthquakes? More than 143 million people are exposed to potential earthquake hazards in the U.S. that could cost thousands of lives and billions of dollars in damage. An understanding of earthquake magnitude and frequency of occurrence is fundamental to earthquake hazard mitigation. An important tool for mitigation is the ShakeAlert® Earthquake Early Warning system for the of the U.S. which detects significant earthquakes quickly so that alerts can be delivered to people and automated systems.


For the 5- and 15-minute activities, learners should be able to:

• Explain the unpredictability of magnitude and timing (frequency) of earthquakes as a part of the natural Earth system.

• Describe the global trends for earthquakes.

For the 45- to 60-minute activity, learners should be able to:

• Critically analyze data generated by the Earthquake Machine and use the data to develop an evidence-based response to a provided claim statement.