Structure of the Earth

The Earth is enormous but we can’t see most of it because it’s deep down underground.  Let’s look at how the Earth is like a ball composed of different layers. Find out more about Structure of the Earth!

Crust – All the rocks and dirt that we can see, or dig down into, make up the outer layer of the earth called the crust.  Just like the crust on a big pizza, the earth’s crust is just a thin layer over top of the mantle, which makes up the biggest portion of the Earth.

Mantle – The mantle is composed of heavy rock that is deep in the earth and therefore subject to intense heat and pressure.  In the Upper Mantle, the rock is mostly solid but the rock in the Lower is so hot that it’s close to melting, or ‘plastic’, which means the rock can move and flow a little.   Scientists believe that huge chunks of mantle, with thin crusts on top, move around, causing earthquakes at the earth’s surface.

Core – The core of the Earth is so deep and hot that no one has ever been able to drill down to it.  However, by sending energy waves down into the earth and recording how they reflect back up, scientists believe they know what the core is like.  The Outer Core, is made up of the heaviest elements in the earth like iron and nickel, and is liquid because it’s so hot that nothing can stay solid.  However, the very center of the Earth is under so much pressure that, although it’s even hotter, the heavy elements in it can’t melt, so the Inner Core is solid.

Atmosphere – Of course, there’s one more layer to the Earth – the atmosphere!  This is the thin layer of air that surrounds the Earth and separates us from outer space.