1. Layers of the Earth

2. DECEMBER 19 Layers of the Earth
Get out your note books and label a new page with today’s date and the title of this unit.
DECEMBER 19
Layers of the Earth

3. How deep is the deepest hole that we can dig?
Write the stuff in Green in your notes.

5. http://www.bbc.com/future/bespoke/story/20150306-journey-to- the-centre-of-earth/

6. We have dug
40, 603 feet deep.
(7.7 miles, 12.4 Km)
It would take another 60,000 feet (18 Km) to reach the bottom of the earth’s crust, the very outer layer.

7. Why does the earth have layers?
Turn and talk to your neighbor.

9. Why does the earth have layers?

10. Make some observations about sediment tubes

11. So…if we can’t actually dig that deep… How do we know what materials make up the earth’s layers? How do we know if it’s solid or not?

12. How do we know what materials make up the earth’s layers?
By studying data from earthquakes
Seismic waves travel faster through denser materials…like iron…
And slower in less dense materials …like molten rock or lava

13. We are going to make a model of the layers of the earth.
Important stuff to know: 1. What’s it make of (chemical composition) 2. Density of that stuff (why it’s in layers) 3. Temperature at that depth

14. Tape the information sheet into your notes:

15. Start with the atmosphereᵒC
Nitrogen,
Oxygen,
CO2
Gas
500 Km
.001
-55 to 100

16. Look at the globe. It is a model of our earth.
The Crust is the next layer
Look at the globe. It is a model of our earth.
The crust covers the sphere completely.
The crust is under the oceans.
Where the lowest parts of the crust are is where the water gathers.
The highest points are land and mountains stick up even higher.

17. ᵒC 1
H2O
liquid
Granite
Basalt
8-32 Km
30-400
Solid

18. Mantle Has a tar-like consistency (melted rock)
Flows in Convection Currents
Is the reason our continents move
Made of Silicon, Magnesium

19. 2700 Km 3.4-5.6 800-2000 Melted Tar Granite, Basalt Silicon, Magnesium

20. Outer Core Very Hot!!! Made of Nickel and Iron (very dense materials)
Melted into a liquid
Makes our magnetic field

21. ᵒC
2200 Km
Nickel, Iron
Liquid

22. Inner Core Even hotter! Why is it hot? Where did it get its heat from?
Turn and talk to your neighbor

23. Where does Earth get its hot inner core?
1. Heat comes from the smashing together of the matter when it was formed
Clap your hands together hard enough for long enough and your hands will get warmer
That heat has been insulated by the outer layers, so it stayed hot over a long time
2. Heat also comes from the decay of radioactive elements, just like a nuclear power plant, but slower

24. ᵒC
1200 Km
Nickel, Iron
Solid

25. If the inner core is hotter than the outer core, why is it solid instead of liquid?
Turn to your neighbor and discuss

26. If the inner core is hotter than the outer core, why is it solid instead of liquid?
The tremendous pressure of the rock around the inner core makes it a solid because the molecules cannot expand enough to be a liquid.