The Bedtime Scientist

A question

Why do volcanoes erupt?

A calm, true answer. Then, if the wondering keeps going, the whole episode.

The short answer

Because melted rock is lighter than the solid rock above it, so it rises. Gas dissolved inside it expands as it nears the surface, rather like a shaken bottle when the cap comes off.

Most eruptions are not explosions at all. Most are slow and oozing, and they build land rather than destroy it. Hawaii was made that way, layer by patient layer, and volcanic soil grows some of the richest farmland on Earth.

Go deeper tonight

Volcanoes: How the Earth Breathes

The full episode, in one calm voice, with nothing that startles.

The episode

Volcanoes: How the Earth Breathes

0:00 11:00
Sleep timer

Read the guide for this one in the morning.

This connects to

Air and pressure Heat and energy

One idea turns up in many different nights. Follow one and the library starts to join up.