Final Answer:
1. Crust – hard and rigid, the Earth’s outermost and thinnest layer. Only a few miles (5 km) thick under the oceans and averaging 20 miles thick under the continents.
2. Mantle – Divided into two sub regions, upper and lower, this dense layer made of hot semi rock is located directly below the crust and is about 1800 miles thick.
Lithosphere – made up of the crust and tiny bit of the mantle, this layer is divided into several constantly (very slowly) moving plates of tectonic plates that hold the continents and oceans.
Asthenosphere – The plates of the lithosphere move (on top) on this hot, malleable semi liquid zone in the upper mantle, directly below the lithosphere.
3. Outer Core – The only liquid layer of the Earth – a sea of mostly iron and nickel. It is roughly 1800 – 3200 miles below the surface and about 1400 miles thick. Temperatures reach 4000–5000° C.
4. Inner Core – An extremely hot, solid sphere of mostly iron and nickel at the center of the Earth. It is 3200 to 3960 miles below the surface and about 750 miles in diameter.
How do you think scientists discovered the layers of our Earth?
They studied how seismic waves from earthquakes travel through the Earth — different layers bend or block the waves in different ways, helping scientists figure out what’s inside.
Parent Tip: Review the logic above to help your child master the concept of layers of the earth worksheet middle school.
