Layers of the Earth Facts for Kids
Let’s explore some facts about the layers of the earth! Then, why not take a look at the activities to support your learning in the section at the end to test what you have learned?
So, what is in the centre of the Earth?
The Earth is made of three layers that are just like an onion. These are the crust, the mantle and the core. These three layers of Earth are both physically and chemically different.
Some of these layers have even more layers in them and they are always moving.
The Earth is mostly made of rock and metal. As scientists can’t really get right to the middle of the earth, it’s not easy for them to know what’s way down in the middle.
How did scientists determine Earth has layers?
Scientists use waves to study the different layers of the earth. They rely on seismic and magnetic analyses to investigate the Earth’s structure.
There are always new theories coming out as measuring equipment and knowledge improves.
3 Main Earth’s Layers
#1. The Core
The core is made of two layers – the inner and outer core. When the Earth formed 4.5 billion years ago, the heavy substances sunk to the middle and these formed the inner core.
The lighter ones, like air and water, stayed on the top on the crust.
The inner core is a bit like a solid lead ball, which is about 1,500 miles (2,400 kilometers) thick. That is thick!
Earth’s inner core is the innermost geologic layer of planet Earth.
Under all that pressure, it actually can’t melt. Are you ready for this? It is between 9,000 and 13,000 degrees Fahrenheit (4,982 and 7,204 degrees Celsius) in temperature.
That is seriously hot and unbelievably it’s as hot as the sun’s surface.
When you consider that a kettle reaches 212 degrees Fahrenheit (100 degrees Celsius) at boiling point, then you can imagine just how hot the inside of the Earth is!
The inner core is said to spin at a different speed to the rest of the planet causing the Earth’s magnetic field.
The outer core is the liquid largely iron and nickel layer of the earth that lies below the mantle. It is about 1,400 miles (2,300 kilometers) thick.
Some people have said that it is actually 3,200 miles (5,150km) thick and 7,200 to 9,000 degrees Fahrenheit (3,982 to 4,982 degrees Celsius) in temperature.
It is because of the flow of metals in this inner core that the Earth is magnetic.
The influence of this magnetic field extends beyond the Earth far into space and forms a barrier that helps protect the Earth from the Sun’s destructive solar winds. Wow that’s interesting.
How hot is the core of the Earth?
The Earth’s core is same temperature as the surface of the Sun – now estimated at 6,000 C (about 10,800 F). The fluctuating temperatures in the core depend on pressure, the rotation of the Earth, and the varying composition of core elements.
#2. The Mantle
The mantle earth layer is about 1,800 miles (2,900 kilometers) thick and makes up about 85% of the Earth’s weight.
It is made of molten (melted) iron, minerals and other semi-solid rocks that can flow under pressure.
It is thought that when the rocks rise due to the very intense heat and then cool, this means that they sink back to the core and this movement causes the crust to break into sections, or plates.
When these move and crash into each other it causes earthquakes and volcanic eruptions. It is because of this movement that mountains and new sea floors are formed.
Sea floors are made of a thick rock called basalt which press into the mantle and then fill with water.
The various continents are made from lighter blocks that float on the mantle like massive icebergs.
When the mantle layer is explored they usually do it from the sea bed where the layer is thinner than on land.
The first time they explored the mantle was in 1996, but they eventually gave up as they just couldn’t get it right.
In 2007, scientists drilled to 23,000 feet (7,000 m) below the seabed from a Japanese ship called Chikyu, in an area between Cape Verde Islands and the Caribbean Sea.
This drilling was three times deeper than any other previous drillings that they had done.
How hot is the mantle of the Earth?
The temperature of the mantle varies greatly, from 1000° Celsius (1832° Fahrenheit) near its boundary with the crust, to 3700° Celsius (6692° Fahrenheit) near its boundary with the core.
#3. The Crust
The crust is an outer solid layer and is where life as we know it exists with mountains, sea and soil. It is about 3-5 miles (5 – 8 kilometers) thick in the ocean bed.
It is mostly made from basalt rock and is around 25 miles (40 kilometers) thick on land which is mostly made from granite rock.
This is the only layer of earth that can be investigated by drilling into it. So we know way more about his layer than any of the others!
Seismic Waves
The layers beneath the crust are investigated by watching how the waves that travel through the Earth (Seismic waves) from earthquakes or eruptions, behave.
The machine that is used to measure these waves is called a seismograph.
Interesting Facts About the Earth’s Layers
Did you know that the inner core and the outer core of the Earth are as big as Mars?
Meteorites have bits of nickel and iron in them and scientists believe that they may be pieces from other planets which have exploded!
The mantle of the earth is solid rock, but amazingly it can be moldable, just like play dough. I don’t think that this is the type of stuff to play with as it’s so crazy hot!
Activity Time – Test Your Knowledge!
Test your knowledge of this subject using our activity sheet to use in class or at home: 
Questions about Layers of the Earth (all answers found on this page).
Also check out the Layers of the Earth Activity – Playdough Planet activity on our blog!
