The depths of the ocean remain the final frontier of human exploration on Earth. It seems like every other day, scientists are announcing the discovery of some new, previously unknown—and probably hideous—species in the briny deep. Who knows what other wonders our mighty seas hold?
One interesting fact that your students probably don’t know: the ocean floor is covered in peanut butter. Okay, that’s completely untrue, but the surface of the ocean floor can change so much, so quickly that it wouldn’t surprise me one bit if an oceanographer popped out of his research submarine and was like, “Yep, extra crunchy for miles down there!”
To help your students better understand just how quickly the ocean floor can shift and change (and to give yourself a handy excuse for a mid-class snack), we present this easy-peasy-lemon-squeezy Demo Science science demo. Check it out!
20,000 Graham Crackers Under the Sea
For this experiment, you’ll need just a few delicious supplies: graham crackers and peanut butter. Though crunchy peanut butter is the superior style in every other way, creamy PB actually works better for this demo. It’s probably best to make sure you’ve enough graham crackers and peanut butter for your students as well (you know how whiny kids can be always are). You’ll probably also want to bring in a roll of parchment paper, unless you want to clean peanut butter off a bunch of desks.
Gather your students around, then splorp a dollop of peanut butter on your desk or other hard, flat surface. Take two graham crackers and place them side by side, with their edges touching, on top of your PB blob. Doesn’t matter what sides/edges.
Press down gently but firmly, and slowly slide the crackers away from each other. As they slide apart, the peanut butter should ooze out from betwixt and below them.
Pass some squares of parchment paper around, then distribute graham crackers and PB to each of your students and let them recreate the experiment themselves. When they’re done learning, they’re free to devour their supplies (except the parchment paper) as you fill them in on the science-osity of what just went down.
Jif, Reese’s, Peter Pan, Skippy… It’s All Science!
The peanut butter smooshing out from the growing space between your graham crackers is a tasty visual representation of the continual growth and change of the ocean floor. Liquid hot magma circulates convectively in the mantle below the earth’s crust, and forces its way out through divergent boundaries between tectonic plates. A prime real-life example of this process is the Mid-Atlantic Ridge, which is basically the George Clooney of oceanic geological ridges.