This post is part of our Drawn to Geoscience series where our own JoAnna Wendel creates (and explains her process for) comics of geoscience research.

A common challenge in cartooning: How do you show movement? If I could animate, it would be much easier showing transitions between states.

For example, in a new comic for Bethany Brookshire’s weekly science newsletter “Are You Scicurious?”, I describe how carbon dioxide dissolved in subsurface water helps a geyser erupt. One of the sticky points for a concept like this is how do I show the carbon dioxide dissolving and then creating bubbles in the water? How do I show water transition from a state of extreme pressure to less pressure? Without an animation, it’s hard to show things changing.

When planning out this comic, I had this, and several main ideas in mind:

1. Gotta feature images of the geyser actually exploding. Everyone loves when things explode.
2. I have to figure out a way to show how carbon dioxide and water change from one state to another.
3. I have to figure out a way to show water under pressure, moving underground.
4. I have to figure out a way to show what’s happening beneath Yellowstone in an easy-to-understand way while staying scientifically accurate.

For the water problem, I ended up drawing a simple representation of a “pipe,” since science communicators often refer to the deep workings of a volcano as its “plumbing.” Even if there aren’t perfectly tubular spaces that water or magma travel through, it’s an easily-understandable way to represent fluids moving underground. And the concept remains accurate—deep underground, water is under so much pressure that it can’t expand or boil.

For the carbon dioxide problem, I used arrows to show that the molecules moved from the magma, to the rock, to the water. I then decided to show three different scenes while using words to describe the process. Water starts to bubble, carbon dioxide bubbles form in the underground passages, throw in a little anthropomorphizing of carbon dioxide molecules, and you’ve got yourself a good progression of events.

For the Yellowstone piece, it was simplest just to go with a cross-section showing Earth’s different layers. Lots of diagrams already exist showing the plume of magma rising through the mantle and bumping into the crust—I just looked at one and create my own simpler version, with some added giant-bison humor. When writing the accompanying text, I originally called Yellowstone a “caldera.” But Bethany pointed at that this is probably too much of a jargon word for a casual reader, so I changed it to “supervolcano,” which many general readers would connect with Yellowstone.

(PS: If you want to receive the weekly newsletter featuring science news and my comics every Sunday, see the letter archive here, and subscribe here!) Check out the comic below!

–JoAnna Wendel (@JoAnnaScience), Eos Staff Writer