Explore the Volcano Eruption & Magma Dynamics Lab
Control magma temperature, silica and gas content and watch the eruption style flip between a gentle lava flow and an explosive blast.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
Illustration. Open the tool for the real thing.
See it in action
The Volcano Eruption & Magma Dynamics Lab with sample data entered and the result showing.
What is the Volcano Eruption & Magma Dynamics Lab?
Control magma temperature, silica and gas content and watch the eruption style flip between a gentle lava flow and an explosive blast. It runs in your browser, so a change to a setting or a drag on an object shows up at once.
Volcanologists use exactly these viscosity-silica-gas relationships to forecast whether a volcano like Kilauea (effusive) or Mount St. Helens (explosive) will erupt gently or catastrophically.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
Viscosity rises steeply with silica content and falls as magma gets hotter.
Thick, viscous magma traps gas bubbles until pressure shatters it into ash: that is an explosive eruption.
Runny, low-silica (basaltic) magma lets gas escape smoothly, producing effusive lava flows.
Push silica above 65% and gas above 3% and see the eruption turn explosive.
Set silica low and temperature high for a lazy effusive flow.
Try the challenge: reach an Explosivity Index of 7 or higher.
Used for
Pick one to see how it fits.
Teachers
For teachers: project the Volcano Eruption & Magma Dynamics Lab on the board, let students predict the result, then run it together and test this: Set silica low and temperature high for a lazy effusive flow. For students: change one thing at a time and write down what changes.
Try it freeHow it compares
A plain look at this tool next to the usual alternative.
| This simulation | Textbook diagram | |
|---|---|---|
| Interactive | Drag, tap and change settings | Fixed picture |
| Install | Nothing to install | Not needed |
| Cost | Free to use | Depends on the book |
Questions people ask
Why is rhyolite more explosive than basalt?
Rhyolite has more silica, which makes long silicate chains that raise viscosity, trapping gas until it bursts out violently.
What is the Volcanic Explosivity Index modeling here?
A simplified index combining viscosity and gas content, matching the real pattern that gassy, viscous magma erupts more explosively.
Is the Volcano Eruption & Magma Dynamics Lab free to use?
Yes. The Volcano Eruption & Magma Dynamics Lab is free, needs no signup or download and runs in your web browser. It is part of the Geology group of AZRS simulations.
Does the Volcano Eruption & Magma Dynamics Lab work on a phone or tablet?
Yes. The Volcano Eruption & Magma Dynamics Lab takes touch input as well as mouse input, so you can use its 5 adjustable settings with a finger. A larger screen makes the controls and graphs easier to read.
How do I use the Volcano Eruption & Magma Dynamics Lab?
1. In the Volcano Eruption & Magma Dynamics Lab, use the controls to change Magma temperature, Silica content (SiO₂), Dissolved gas content, Chamber overpressure, Vent diameter. The simulation reacts instantly. 2. In the Volcano Eruption & Magma Dynamics Lab, press "Trigger eruption", "Reset chamber" to start, reset or change what is happening. 3. Start with this experiment: Push silica above 65% and gas above 3% and see the eruption turn explosive. Drag any glowing handle, object or slider with your mouse or finger and the Volcano Eruption & Magma Dynamics Lab responds in real time. 4. Change one setting at a time and watch which readout moves, then compare it with this idea: Viscosity rises steeply with silica content and falls as magma gets hotter.
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Try the Volcano Eruption & Magma Dynamics Lab now
Control magma temperature, silica and gas content and watch the eruption style flip. Free to use.
Try it free