Inside the Earth: earthquakes and volcanoes, in 3D

What the simulation shows

• The Earth cut open to scale: crust, mantle, outer core, inner core (labelled).
• Close on the core: the solid inner core glowing, as hot as the Sun's surface.
• Currents in the mantle: hot rock slowly rising and cooler rock sinking.
• A cross-section: an ocean plate moving away from a ridge where new rock rises.
• The ocean plate diving under a continent (it's heavier).
• The diving plate melts; magma rises and a volcano erupts above it.
• Crust crumpling upwards into mountains where the plates push.
• A fault seen from above: a road across it bends as stress builds, then the blocks suddenly slip and snap it.
• Seismic waves rippling out from the quake; the seismograph swings; a callout: magnitude 7.

The real numbers it runs on

The simulation is built on these facts, so the narration and the picture always agree:

• The Earth has four main layers: a thin rocky crust (5 to 70 km), the mantle (hot rock that flows very slowly, down to 2,900 km), a liquid iron outer core and a solid iron inner core, about 5,400 °C, as hot as the Sun's surface. It's 6,371 km to the centre; the deepest hole ever dug reached 12 km.
• Heat from inside keeps the mantle slowly churning; the crust is broken into plates that ride on it, moving about 5 cm a year, about as fast as fingernails grow.
• At mid-ocean ridges plates move apart and magma rises to make new crust. Where an ocean plate meets a continent it dives under it (subduction), because ocean crust is heavier.
• The diving plate melts, and the magma rises to feed volcanoes: the Pacific 'Ring of Fire'.
• Where plates push together the crust crumples into mountains: India pushing into Asia raised the Himalayas, still rising about 5 mm a year.
• At a fault the plates lock and stress builds for years; when it snaps, the rock slips metres in seconds: an earthquake. Each step up in magnitude is about 32 times more energy.

The script this video was made from

“Why the ground shakes”: the narration of the video above. Each highlighted moment in the simulation happens on the word that names it.

Make your own

1. Type a question, like “Why the ground shakes”, or your own angle on it.
2. ContentRoof picks this simulation, researches the facts and writes a short script, with every moment cued to a word.
3. A natural voice reads it in your language and the simulation plays in time with it. Change any line and it follows.
4. Download a vertical video for Shorts, TikTok and Reels, or use it in class.

Make this video →

Questions

More 3D simulations

How the heart pumps bloodBody organsHow the lungs workBody organsThe digestive systemBody organsHow a muscle moves a boneBody organsHow the eye worksBody organsHow a vaccine trains your immune systemCells and microbesDNACells and microbesHow a neuron sends a signalCells and microbes

All 29 3D simulations →