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Inside a Volcano

Understand the inside of a volcano: magma is hot melted rock underground, lava is the same material after it reaches the surface, and volcanoes have a magma chamber, vent, and crater

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What a learner can do afterwards

  • Explain that magma is melted rock underground and lava is the same material above ground
  • Label a magma chamber, vent, and crater on a volcano cross-section
  • Describe the path magma takes from underground to the surface during an eruption

The lesson

Deep under a volcano there is hot, melted rock. While it is still underground, we call it magma. When magma pushes up and reaches the surface, it gets a new name: lava. Magma and lava are the exact same material. The only thing that changes is where it is.

ChamberVentCraterLava
Magma sits in the magma chamber, rises up the vent, and comes out through the crater. Once it is out, it is called lava.
Try it together

Picture a volcano like a mountain with a hidden pocket of melted rock inside. That pocket is the magma chamber. A narrow pipe called the vent connects it to a bowl-shaped opening at the top, called the crater. When the volcano erupts, magma rushes up the vent and flows out of the crater.

Good to know

Here is a simple trick: if it is still under the ground, call it magma. As soon as you can see it flowing outside, call it lava.

Magma is melted rock underground. It travels up through the vent from the magma chamber and becomes lava once it flows out of the crater.

Watch it

Where it sits

Where this leads

Jobs that lean on this skill. Follow one to see everything it is built on.

Then practise

8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.

Inside a Volcano · Science, ages 7 to 9 · LightMySky