Earthquakes: They’re Earth-Shattering!

This week students became seismologists, studying the origin, nature, and effects of earthquakes. We began with an introduction to the structure of the earth’s interior and the tectonic plates that form its outer layer. We discussed the damage that quakes can cause, as well as why some regions are more likely to have earthquakes than others, depending on the type of tectonic plate boundaries they are near. We emphasized the different landmasses that result from the different movements of the plates.

Some food for thought: Along which boundaries would earthquakes be more common: convergent, transverse (transform), or divergent? Why? 
[hint: Which ones would store the most energy due to “stress/tension” created by the movement of tectonic plates? 
There could be more than one answer!]

After our initial discussion, students worked through a series of workstations to demonstrate different aspects of earthquakes, including the structural integrity needed for buildings to help survive a quake and how plate boundaries relate to the number of earthquakes in an area. Students used an earthquake machine to demonstrate how the plates slide past each other and observed the build up of tension that occurs. The rippling that was observed in the water is similar to the elastic energy that get stored and then released during an earthquake!

After lunch, we learned about P-waves and S-waves, that take place as a result of an earthquake. We compared these earthquake waves to lighting and thunder, where the lighting comes first, just like the P-wave (primary), followed by thunder, similarly to the S-wave (shear). Finally, students did some seismology work in finding the epicenter of an (imaginary) earthquake, given the times that P-waves and S-waves were detected at three different locations. The most exciting part of this epicenter activity was learning to use drawing compasses!

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