How can we model elastic rebound in the classroom?
This animation shows the change in distance over time as the Earthquake Machine overcomes friction and jumps during an "earthquake". Observe that the red line steps up in small increments, while the blue line has large sudden movements, similar to the large movement expected during a catastrophic earthquake along a subduction zone. The change in strain over time is illustrated in the animation linked above: Earthquake Machine: Graphing Time vs Strain. Observe that the strain in the red line constantly builds and is then released, while in the blue line, the strain builds in sudden steps until a catastrophic release of energy occurs.
Model graphs time vs. distance to illustrate:
- Build up and release of strain in the earth.
- The first block simulates small earthquakes between tectonic plates.
- The second block simulates the locked zone of two plates.
- During small earthquakes strain is transferred to block #2
- Strain between the blocks builds until #2 finally moves, equivalent to a major earthquake.