First off, that’s not true. I’ve never written a book on anything. Heck, I can barely read—most of this blog is written via speech-to-text software. Okay, that part’s also not true. Schwhatevs.
Anyhoo, did you know there are different types of earthquakes? Not like “bad ones” and “really bad ones”, but in the way that they occur. There are different kinds of faultline movements that can cause earthquakes. Specifically, there are “dip-slip” fault movements, and “strike-slip” movements. The results are ultimately essentially the same, but the how is different. This easy Demo Science experiment will help you demonstrate that difference to your students.
The Battle of the Century: Dip-Slip vs. Strike-Slip
Good thing you’re in a classroom, because you’ve already got everything you need for this science demo right there. All you need are three hardcover books of roughly the same size. Pretty simple, no?
First, hold the books firmly together in your meathooks, with the spines facing upward. Bring the books in close to your chest, then push up on the middle book so it slides up betwixt the outer books—you may need a student volunteer to help with this part. Repeat the pushing/lifting so the middle book lifts straight and smoothly out from the other two.
Then, reset. This time, hold the books out away from your body while again keeping them held together firmly. Press hard on the two outer books so that the center book stays in place without you touching it. Gradually release the pressure until the middle book slips downward. Catch it between the others if you can, otherwise get ready to break its fall by deflecting it with your foot—you don’t want a banged up spine!
Finally, reset the books and hold them together while resting them on a table or desk. Holding onto the two outer books only, slide the whole mess back and forth repeatedly until it all starts to slide apart.
Are You Sure That’s Science?
It’s totally science! Way, way much science. The first two trials above displayed dip-slip fault movements. In the first part, the book popping up in the middle was reminiscent of a thrust fault; in the second, when the center book slipped down, you created an analog of a normal dip-slip fault. The third trial demonstrated a strike-slip fault, in which the fast buildup and release of friction and energy resulted in movement.