1. Interior of the Earth
Lecture #3

2. Surface
71% water
29% dry land

3. Formation of Earth ~4.6 billion years ago Earth melted
Gravity compressed matter into a smaller volume
Earth melted
Radioactivity
Energy of particle motion transformed into heat
Iron falls toward interior displacing lighter materials
Meteor impacts
Energy of motion –> heat
Collisions with left over material from solar system formation collide with earth.
Earth heats up and liquefies.
Liquid settles out into layers by density.
Meteor impact formed Moon

4. Earth’s Layers Convection causes cooling Settle into 3 layers
Cooled earth off rapidly
Heavy Fe and Ni sank due to gravity
Low density molten materials rose
Settle into 3 layers
Crust
Mantle
Core
Layer’s classified by density of rock.

6. Crust
10 – 100 km thick
1% of Earth’s volume
1% of Earth’s mass

7. Crust 2 Types of crust Oceanic Continental dense rock young
less dense rock
old

8. Mantle About 3000 km thick 80% of Earth’s volume 66% of Earth’s mass
Consists of solid rock
Top flows like molasses.
Caused by High pressure/temperature

9. Core About 3500 km thick 19% of Earth’s volume. 33% of Earth’s mass.
Very dense
90% iron and 10% nickel
2 Parts
Outer Core
Iron and nickel in a liquid state.
Inner Core
Solid iron and nickel

10. Crust/Mantle Interaction
Lithosphere (C/M)
Solid
Floats on asthenosphere.
Asthenosphere (M)
molasses
Mesosphere (M)
Stiffer rock

11. Words of Wisdom