1. Essential Question: How are the Earth’s layers divided?
Earth’s Interior
Essential Question:
How are the Earth’s layers divided?

2. Earth’s Interior Vocabulary
Crust –
Mantle –
Lithosphere –
Athenosphere
Mesosphere
Outer core –
Inner core -

3. Who Studies the Earth’s Structure?
Geology is the study of the solid Earth.
Geologists study the forces that have shaped the Earth throughout its long history.

4. How Do Scientists Know What’s Inside Earth?
Because of the extreme conditions in the Earth’s interior, geologists cannot explore deep into the Earth.
Instead they use seismic waves from earthquakes to study how they travel through the Earth.
The speed of seismic waves and the paths they take reveal how the planet is put together.
Geologists have found that the Earth’s interior is made up of several layers.

5. So How Many Layers Are There?
If you were to travel into the Earth, you would find 3 main layers each with its own conditions and materials.
Crust
Mantle
Core
The deeper into the Earth layers you travel, the greater the temperatures and pressure.

6. Layers Diagram

7. Earth’s Crust The crust is the outermost layer of the Earth’s surface.
The crust is composed of rocks, mountains, soil and water.
The crust is the thinnest layer of all of Earth’s layers.
There are 2 types of crust:
Continental crust that forms the continents made of less dense rocks like granite.
Oceanic crust that is beneath the ocean and made of dense rock like basalt

8. Diagram of Earth’s Crust

9. Earth’s Mantle
Between 5 and 40 kilometers deep, a new layer of hot rock is found called the mantle.
This solid material upper layer of the mantle and the crust form a rigid layer called the lithosphere (100 km thick)
Beneath the upper layer of the mantle is a softer, pliable layer of hot rock called the athenosphere.
The lithosphere “floats” very slowly on top of the athenosphere.
Beneath the athenosphere, is another 2900 km of solid mantle material.

10. Diagram of Earth’s Mantle

11. Earth’s Core
The center layer of the Earth is called the core made of nickel and iron.
The core consists of 2 parts:
Outer core – the layer of molten metal that surrounds the inner core.
Inner core – the dense ball of solid metal due to the extreme pressure there.
The core makes up 1/3 of the Earth’s mass, but only 15% of its volume.
The whole core is a little bit smaller than our moon.

12. Earth’s Core Diagram

13. Let’s Review What is the study of the solid Earth called?
Scientist who study the forces that have formed the Earth’s surface are called what?
What 2 things increase the deeper within the Earth’s layers one may go?
How many layers does the Earth have?
What are the 2 sublayers with the Earth’s interior?
What is the difference between the parts of the core? Why?