VGP Spotlight, September 2014: Back to School Edition
Welcome to the new VGP Spotlight Features! Each month we will be bringing you a short piece from VGP scientists highlighting some aspect of their research, education, or outreach work in the field. Our inaugural edition is geared for the back-to-school theme, given that many of us are doing just that right now.
Spotlight Feature: Explosive Education!
By Karen Harpp1 and Alison Koleszar2
- Geology Department, Colgate University, Hamilton, NY email@example.com
- Jackson School of Geosciences, University of Texas, Austin, TX firstname.lastname@example.org
Ever find yourself teaching volcanology but struggling to convey the power of an eruption to your students? Sure, we can show videos all day long, but it just isn’t the same as witnessing an eruption. What we’re about to explain isn’t the same as being at an eruption either, but it’s a pretty simple, very effective way to inject some volcanic excitement into a class or lab (or just to get a bunch of kids really excited about science)! Below, we present an overview of how to carry out the safe demonstration of an explosive volcanic eruption.
The short version of the demonstration is this: Liquid nitrogen is poured into a soda bottle, which is capped and sunk into a trashcan filled with water (with some alacrity, mind you…!).
Highly skilled volcanology students pour liquid nitrogen into the weighted bottle. We use a metal weight custom-made for us by our machine shop technician, but three bricks duct-taped around the bottle work just fine. After pouring in about an inch thick layer of liquid nitrogen, they will cap the bottle and place it gently into the trashcan full of water (all while wearing safety glasses, of course).
Within 10-15 seconds, the force of the expanding nitrogen propels a column of water 10 or more meters into the air, making a spectacular eruption column. You can watch a (very amateur) version of this here.