Layers of the Earth

1. The Layers of the
Earth!

2. Earth Layers
• The Earth is divided into four main
layers.
*Crust
*Mantle
*Outer core
*Inner core

3. http://www.glossary.oilfield.slb.com/DisplayImage.cfm?ID=124

4. The Crust
* The Earth’s crust is the
outermost surface.
*It is a very thin layer of solid
rock. It is the thinnest layer
of the Earth.
*The crust is 5-35km thick
beneath the land and 1-8km
thick beneath the oceans.
* The crust of the Earth is
broken into many pieces
called plates. The movement
of these plates causes
earthquakes.

5. The Lithosphere
• The lithosphere is composed
of part of the crust and the
upper part of the mantle (the
top 100 km).
• It is composed of hard,
brittle rock

6. The Athenosphere
* The athenosphere is the
part of the mantle
underneath the
lithosphere.
* It is made of molten rock
and metal so that it
“flows” like hot asphalt.
* The athenosphere is the
part of the mantle that
moves and causes the
tectonic plates of the
crust to move as well.

7. The Mantle
* The mantle is the largest
layer of the Earth. It is
2900km thick.
*It includes the lithosphere and
athenosphere.
*It is relatively flexible—it
flows like very viscous liquid.
*It is very hot—1600°F at the
top and 4000°F towards the
center of the Earth.

8. The Core
* The core of the Earth is
like a ball of very hot
metals. The core is divided
into 2 layers—Outer and
Inner.
* The core is SO hot and has
SO much pressure that if
you were to go there—you
would be squished into
something even smaller than
a marble.

9. The Outer Core
* The outer core is liquid
metal iron and nickel
with 10% sulfur and/or
oxygen.
* It is very hot—
4000-9000°F.
* The outer core is
2,250km thick.

10. The Inner Core
* The inner core is solid
metal due to the
extreme heat and
pressure.
* It is composed of iron
and nickel. It is
responsible for the
magnetic field the Earth
generates.
* The inner core is 800km
thick and is 9000°F.

11. Review
1) What are the four layers of the Earth?
2) The Earth’s crust is very ______?
3) The mantle is the largest layer of the
Earth? True or False
4) Is the Outer Core a liquid or a solid?

12. Answers!
1) Crust, Mantle, Outer Core, Inner Core
2) Thin
3) True
4) Liquid