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Volcano: From Magma Chamber to Eruption

Explore underground magma, gases, fractures, and pathways to the surface as a cutaway system.

Cross-section · 1/5

The magma chamber sits far below the ground

A volcano is remembered by the shape of its mountain, but most of the work happens under the ground. The line running across the middle of the cross-section is the ground surface, and everything below it is underground. Five layers of equal thickness are stacked there, and the roof of the magma chamber lies about two and a half layers down. The layers are a depth scale you can count.

Background: USGS: What We Do — Volcano Hazards Program (what is studied, from magma storage below to eruption products at the surface).

Find the ground surface line, then count how many layers lie between it and the magma chamber.

Quiet volcanoQuiet observation

Mission 0%Pressure 28%Risk 35.2%

models/volcano-magma-chamber/model.glb

Observation Mission0%

Check the crater exitTouch the crater pin and set the starting point of the outflow.
Lean toward flowing conditionsWith low viscosity and low gas, see whether lava flow prevails over explosion.
Watch the glowing streak run down the slopeConfirm the state where the lava reach extends and the dark rim with a glowing center spreads down the slope.

Observation PointCrater

Observation pinCraterThe entrance for the plume. The more gas, the higher the ash-laden column rises.

Why This BranchPressure building

Still reading the buildupPressure 28% is rising, but conduit formation and groundwater contact are not decisive. Combine the small earthquakes, gas, and uplift to see the next branch.

Decompression degassing30%

As magma rises and the pressure drops, the dissolved gas becomes bubbles, producing the difference between a plume and a lava flow.

Pressure source28%

The magma chamber does not swell like a water balloon as a whole; the force escapes into fractures and weak places.

Stickiness42%

The higher the viscosity, the more bubbles are trapped; the lower it is, the more gas escapes and it flows out as lava.

View LayerCross-section

Show the volcanic edifice, strata, magma chamber, conduit, and groundwater layer in a readable way.

Live ReadoutPressure building

Eruption risk35.2%

Explosivity30.6%

Lava flow44.6%

Phreatic explosion24.2%

Pyroclastic risk30.1%

Ground uplift3.8cm

Plume height0.3km

Lava reach35.7%

Quakes 27Swarm 31%Gas 34%Ash 30%Steam 23%

Quiet observationFirst read the underground layout. More than the volcano’s outline, where the pressure escapes inside is the key.This model is a pseudo-simulation for exploration. For real volcanic decisions, follow the observations and alerts of the responsible agencies.

Observation Log3

Ground uplift 3.8 cm / volcanic earthquakes 27 / swarm level 31%
Gas emission 34% / plume height 0.3 km / underground pressure 28%
The magma chamber is small and the conduit has not opened yet.

Discovery check

In the cross-section, what is drawn as the ground surface?