The document discusses the four main layers of the Earth - crust, mantle, outer core, and inner core. The crust is the outermost layer and is the thinnest, ranging from 5-35km thick under land and 1-8km thick under oceans. The mantle is the largest layer, making up over 80% of the Earth's volume. It is divided into the rigid lithosphere and flowing asthenosphere. The outer core is liquid, while the inner core is solid due to extreme heat and pressure.

1. The Layers of the
Earth!

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

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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
• On your mantle layer, draw a
dotted line around the very
edge of the circle. This is
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. Draw a
dashed line about an inch
under your dotted line.
* 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