layers of the Earth and its component

1. INSIDE THE EARTH
Plate Tectonics

2. The Composition of the Earth
A. These layers describe the chemical makeup of the
Earth, the compounds found in the layers
B. Crust – thinnest, outermost layer
- Made of oxygen, silicon, and aluminum
1. Oceanic – more dense than continental crust
2. Continental – thicker than oceanic crust
C. Mantle – middle layer (thicker than crust)
- Has more magnesium, so it is more dense than
crust
D. Core – inner layer (most dense layer)
- Made mostly of iron and some nickel

5. Facts about the layers
• The crust can be as thick as 3 miles to 75 miles in size.
• No one has ever been below or even drilled below the
crust.
• The center of the Earth is hotter than the surface of the
Sun.
• The temperatures in the mantle range from 2000-5000 ºF
• The temperatures in the core range from 7000-12000 ºF
• The core creates the Earth’s magnetic field

6. Physical Structures
We think of the Earth as having three layers;
crust, mantle and core. The Earth layers
are also described in a different way.
The five physical layers include:
1. Lithosphere 2. Asthenosphere
3. Mesosphere 4. Outer core
5. Inner Core

8. 1. Lithosphere
A. Consists of the crust and top part of
mantle
• Outermost, rigid layer
B. Made of solid rock/minerals
C. Pieces of the lithosphere are divided
into tectonic plates
• Can contain both continental and
oceanic crust
• Lithos is Greek for “rock”

10. 2. Asthenosphere
A. Under the Lithosphere
B. Part of the mantle
C. Made of bendable rock
1. Like a marshmallow
2. Still a solid but it can move and flow
D. Astheno is Greek for “weak”

11. 3. Mesosphere
A. Below the Asthenosphere
B. Lower part of the mantle
1. Touches the outer core
C. Made of hard strong solid
rock/minerals
D. Meso is Greek for “middle”

12. 4. Outer Core
– hot, liquid layer that is between the
mesosphere and the inner core
5. Inner Core
– center of the Earth
– solid, metal ball
– most dense layer