1. Layers of the Earth Notes

2. Earth’s Layers Earth is divided into layers 2 different ways
Composition
What it’s made of
Physical properties
What can be observed/doesn’t change chemical properties
Crust

3. Earth’s Layers by Composition
Crust
Core
Mantle
Core

4. Earth’s Layers by Composition
Crust
Outermost layer
Thinnest layer
Composed mostly of oxygen, silicon, and aluminum
Two types
Oceanic (found under oceans; more dense)
Twice as much iron, calcium, and magnesium which are more dense minerals
Continental (found under land; less dense)

5. Earth’s Layers by Composition
Mantle
Between the crust and core
Much thicker than crust
Composed of more magnesium and less aluminum and silicon than the crust so it is more dense than the crust

6. Earth’s Layers by Composition
Core
Below the mantle; at the center of Earth
Makes up 1/3 of Earth’s mass
Composed primarily of iron and nickel
Almost no oxygen, silicon, aluminum, or magnesium
Heats the mantle by convection

7. Earth’s Layers by Physical Properties
Lithosphere
Asthenosphere
Mesosphere
Outer Core
Inner Core

8. Earth’s Layers by Physical Properties
Lithosphere
Solid, outermost part of Earth
Includes crust and rigid upper part of mantle
Divided into pieces called tectonic (or lithospheric) plates

9. Earth’s Layers by Physical Properties
Asthenosphere
Found directly under the lithosphere
Tectonic (lithospheric) plates move on this layer
Made of solid rock that flows slowly

10. Earth’s Layers by Physical Properties
Mesosphere
Found directly under the asthenosphere
Lowest part of the mantle
Very strong

11. Earth’s Layers by Physical Properties
Outer Core
Found beneath the mesosphere
Liquid layer of Earth’s core
Surrounds inner core
Made of iron and nickel
Heats the mantle by convection

12. Earth’s Layers by Physical Properties
Inner Core
Found beneath the outer core
Solid layer of Earth’s core
Very dense
Made of iron and nickel

13. Earth’s Magnetic Properties
Earth acts like a giant magnet
Earth (like any manufactured magnet) exhibits 2 poles
North
South
Earth’s outer core spins as Earth rotates
This creates the magnetic field

14. Compass
A compass is composed of a small, light-weight magnet (called a needle)
Balances on a point
One pole of the magnet will be attracted and point toward the Earth’s North Pole
This pole on the magnet is called the north pole of the magnet
Compasses are used for navigation from any point on Earth’s surface
Possible because of Earth’s magnetic field

15. Layers of Earth Comparisons
PHYSICAL PROPERTIES
COMPOSITION
Crust
Lithosphere
Mesosphere
Mantle
Asthenosphere
Core
Outer Core
Inner Core

16. Layers of Earth Comparisons
Crust
PHYSICAL PROPERTIES
COMPOSITION
Lithosphere
Mesosphere
Mantle
Asthenosphere
Core
Outer Core
Inner Core

17. Layers of Earth Comparisons