1. Today’s Warm-Up Friday, January 10
Write What You Know! Write as much as you can for five minutes on the prompt below, try for at least 3-4 complete sentences.
Astronomy Throwback! Do other planets in our solar system also have layered atmospheres and layered interiors like the Earth does? Why?
Why is the Earth’s core made of metal, and the mantle and crust made of different types of rock? Why isn’t everything the same inside the planet?

2. Earth’s Interior
Section 1.1

3. Exploring Inside Earth
How do we know about the Earth’s interior structure?
Direct Evidence: Rock Samples
From drilling, volcanoes, and tectonic movement
Indirect Evidence: Seismic Waves
Energy waves from earthquakes, change path and speed as they move through the Earth. Why?
Waves travel differently through different materials

5. Journey to the Center of the Earth
As you go deeper into the Earth . . .
Temperature increases, it gets hotter!
Pressure increases
Material becomes more dense
Materials change from lighter rock to heavier rock to metal
Lots of water trapped inside Earth!

6. Crust Crust is solid, rigid rock Breaks under pressure
Broken into many tectonic plates

7. Crust How far down have we gone? Deepest bore hole (drill) 12 km down
Deepest cave discovered
3 km down
Border between crust and mantle
5 km average oceanic crust
70 km average under mountains

8. Mantle
Rock samples from:
- Volcanic eruptions
- NOT DRILLING!
Lithosphere: solid, rigid, tectonic plates (crust and upper mantle)
Asthenosphere: solid, plastic, convection currents (middle mantle)
Mesosphere: solid, rigid (lower mantle)

9. Core Outer Core: liquid metal (nickel & iron)
Inner Core: solid metal (nickel & iron)
Why is Inner Core solid not liquid?
PRESSURE!

10. Magnetic Field

11. Magnetic Field The Earth rotates to the east
Outer core rotates west, inner core rotates east, in the opposite direction!
Speed of core’s rotation is faster than the planets, and changes over time!
This generates our magnetic field, or magnetosphere
Protects us against solar wind! Creates auroras at the poles!
What would happen if the entire core cooled down into solid metal and stopped rotating?