What is the Earth Made of?

Part of Planet Earth Week

So what is Planet Earth made up of...


  • It's the thinnest layer of the earth.
  • It is made up of both oceanic and continental crust.
  • The oceanic crust (the area under our oceans and seas) is roughly 7 km (5 miles) thick and composed of the dark igneous rock basalt. Basalt is formed underwater when lava reached the earth's surface at a mid-ocean ridge - we heard about this when looking at Tsunamis!
  • The continental crust averages 35 km (22 miles) thick but will be much deeper - as much as 70 km (40 miles) in some mountainous regions of the world.


  • The Mantle is the second layer of the Earth and makes up around 84% of our planet!
  • It is divided into 2 sections - the Upper Mantle and the Lower Mantle
  • The mantle is much thicker than the crust and is almost 3000km deep and is made up of hot, solid rock.

Tectonic Plates

  • The Tectonic plates are a combination of the crust and the outer mantle
  • They actually move but very very slowly only a few inches a year
  • When they touch each other it is called a fault and can cause an earthquake or a volcano- we will learn more about Tectonic Plates later in the week.

Outer Core

  • The Earths outer core is very very hot and is made up of iron and nickel
  • It is so hot that it is actually liquid!
  • It creates something called a magnetic field which is very important as it creates a protective shield around us to protect the earth from the sun's solar winds!

Inner Core

  • The inner core is made up of iron and nickel also but it is under immense pressure and although just as hot this means it stays solid!

Now have a go at our activity to make a pop-up card activity with all the layers of the earth detailed!

We also have a game for you to play that will help you to learn all about the layers that make up Planet Earth!

Just do the first level as you will need to learn about Tectonic plates to do the next section!

Make Pop-Up Earth
Make Pop-Up Earth (PDF)

Slip Slide Collide (Open University)
Slip Slide Collide (OU)

This page is part of the Planet Earth Week information.

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