ENS

What Is a Volcano?

Start Here

Look First

An active volcano with glowing lava flowing down its dark rocky sides and a large plume of grey ash rising into the pale sky.
  1. What do you think is happening in this picture?
  2. Does the volcano look beautiful, frightening, or both? Why?
  3. Would you like to see a volcano like this in real life? Why or why not?

Before You Read

Words You Need

Learn

Read and Listen

Volcanoes are found in many parts of the world. Some are far from towns and cities, but people live near others. Many volcanoes look like mountains, and they may stay quiet for hundreds of years.

Far under the ground, rock can become so hot that it turns into liquid. Gas in this hot rock can create pressure. The pressure can push the rock toward the top of the volcano. When hot rock, gas, and ash come out, the volcano erupts. This is called an eruption.

The hot rock that comes out is called lava. It can move quickly down the sides of the volcano. An eruption can also send ash, gas, and pieces of rock high into the air. This can be dangerous for people who live nearby.

Scientists watch volcanoes that may erupt again. When they think an eruption is coming, they warn people nearby. People may need to leave their homes and move far away until it is safe to return.

Quick Check

Understand It

  1. All volcanoes are far from towns and cities.
  2. Rock under the ground can become so hot that it turns into liquid.
  3. An eruption can send ash, gas, and pieces of rock into the air.
  4. What can pressure do inside a volcano?
  5. What may people need to do before an eruption?

Build

Chunks

Place

  1. Hot liquid rock is the ground.

  2. Pressure pushes the hot rock the volcano.

  3. Hot rock, gas, and ash come the volcano.

  4. Lava can move the volcano.

down the sides of far under out of toward the top of
A cutaway view of a volcano shows hot liquid rock far underground, rising through a passage to the crater, coming out with ash and gas, and flowing as lava down the volcano’s sides.

Repeat

far under
Hot liquid rock is far under the ground.
toward the top of
Pressure pushes hot rock toward the top of the volcano.
out of
Hot rock, gas, and ash come out of the volcano.
down the sides of
Lava can move down the sides of the volcano.

Now Try

Use It

Supported output: Volcanoes can...
Supported output: During an eruption...
Supported output: Living near a volcano might be...
Extend topic: If scientists warned me about an eruption, I would...
Extend topic: Have you ever seen a volcano in real life?
Extend topic: Would you like to visit a quiet volcano? Why or why not?
Extend topic: What would you take with you if you had to leave your home quickly?
Extend topic: Where would you go until it was safe to return?

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