Mock volcano entertains geography students

By Matthew Rainwater

DeKALB | There was a volcanic eruption late Tuesday morning outside Davis Hall on the east side, in the sitting area by the fountains.

There’s no cause for alarm and please, do not evacuate the campus at this time. It was only a demonstration featuring a volcano in a garbage can for Beth Johnson and Chris Greer’s introductory geology courses.

Johnson and Greer are both lecturers and teaching assistants working on their PhD’s. This demonstration should be left to professionals, as there is handling of liquid nitrogen, which rests at negative 300 degrees Fahrenheit.

Students in both classes were told to meet outside Davis Hall and that something was going to explode. Johnson and Greer had been discussing volcanoes in their classes for the past few weeks, so students were ready for something interesting.

Johnson and Greer explained the process to their students and told them what to expect and look for during the demonstrations. They used water balloons, ping-pong balls, whiffle balls and Styrofoam packaging peanuts to demonstrate the distribution of volcanic materials.

For everything to work, both instructors duct-taped a Coke bottle filled with liquid nitrogen between two bricks so the bottle would sink to the bottom. The first experiment used a one-liter Coke bottle, creating a high burst of power due to holding four atmospheres of pressure, sending water shooting high into the air.

The explosion was exciting and unexpected, said freshman sociology major Andy Rifkin.

For the second experiment, a 20-ounce Coke bottle was put into a garbage can. The smaller bottle created a mushroom-cloud effect, making a much smaller explosion than the first one. This occurred because there was less room for the pressure to build within the bottle.

“There is better eruptions with the use of a Coke bottle due to its shape, and creates better results than a Pepsi bottle,” Johnson said. “Because Coke bottles are more narrow than a Pepsi bottle.”

Johnson first found out about the demonstration while attending Augustana College. She wanted to share the experience with her students.

“I want my students to enjoy and have some fun while watching this demonstration because it stays with you and I want them to take this knowledge and apply it elsewhere,” Johnson added.

Matthew Rainwater is a Campus Reporter for the Northern Star.