Earth is divided into layers including the crust, mantle, and core. The crust is the outermost layer and varies in thickness, being thicker under mountains and thinner under oceans. Below the crust is the mantle, which makes up over 80% of the Earth's volume and consists of hot, dense rock. The mantle is divided into the upper and lower mantle. The outer core is liquid and thought to drive the Earth's magnetic field. Within the core is the solid inner core.

1. Earth Layers

2. Earth is divided into 3
basic layers:
1. Crust
2. Mantle
3. Core
These layers are then
subdivided into smaller layers.

3. Earth Layers
CRUST:
•Is the outermost layer on the earth.
•Thickness varies. Under mountains it
can be as thick as 60 km and less
than 5 km under the ocean.
•It is the least dense of all the layers.
(lightest layer)
•It is made up of silicon and oxygen

4. 2 TYPES OF CRUST:
• Continental crust
is less dense,
made of Granite.
• Oceanic crust is
very dense, made
of Basalt.

5. 2 TYPES OF CRUST:
• Continental crust is less dense,
made of Granite.
• Continental crust has a thickness
of 35 to 40 kilometers
and is mainly made up of the
elements sodium,oxygen, silicon,
aluminum, potassium, and
calcium.
• The continental crust is usually
found under land masses

6. 2 TYPES OF CRUST:
•Oceanic crust is very dense,
made of Basalt.
It has a thickness of 7 to 10
kilometers and found under
ocean floors.

7. BASALT GRANITE

8. MANTLE:
• Located below the crust.
• It is the largest layer (about 2900
km thick). Rock layers are
movable. (plastic)
• Hot soften rocks made up of more
magnesium and iron.
• Density increases with depth due
to increase in pressure.

9. MANTLE:
•The mantle makes up 80 percent
of the earth’s volume and 68
percent of the earth’s mass.
•It consists a temperature ranging
from 15,000-30,000 degree Celsius
•It is made up mostly of silicate
rocks made up of elements Fe, Si,
O and Mg.

10. MANTLE: Divided into 2 parts
• Upper mantle- 670 kilometers
thick
•Lower Mantle - 2230 kilometers

11. “Gutenberg Discontinuity”
named after Beno Gutenberg who
is an American-German
Seismologist it is the boundary
between lower mantle and outer
core.

12. The boundary between upper
mantle and crust, is called
“Mohorovicic Discontinuity”
named after Andrija Mohorovicic
who is a Croatian Meteorologist
and Seismologist

13. ASTHENOSPHERE:
• Soft – can bend like plastic, layer in the
upper portion of the mantle
• It is located right below the Lithosphere.
Lithosphere floats on this layer (like
jello)

14. CORE: Located below the Mantle.
• It is divided into 2 layers
Outer Core
Inner Core

15. Outer Core:
• is liquid and is made up of mostly
iron (easily magnetized)
• The movement of materials in the
liquid O.C. is inferred to be the
cause of Earth’s magnetic field!
• The O.C. is about 2250 km thick.
•It was theorized that the liquid O.C.
is ithe source earth’s magnetic field.

16. Inner Core:
• Is the center of the Earth –
1200 km thick.
• It’s solid iron and nickel. Most
dense layer (heaviest)
• The increased pressure
causes the I.C. to be solid

17. The boundery between outer
core and inner core is called
“Lehmann Discontinuity.”
Named after Inge Lehmann a
Danish Seismologist who
discovered that the inner core
is solid while the outer core is
made up of molten materials.

18. CRUST
MANTLE
OUTER CORE
INNER CORE
Lithosphere
Asthenosphere
In your notes lets draw together a
diagram of the Earth