The Earth’s Interior

1. The Earth’s Interior

2. The earth is constantly ________ changing Throughout its long history, the surface has been ___________________________________ lifted up, pushed down, bent and broken

3. Volcanoes give us a clue as to what is deep, ________________ beneath our feet

4. The deepest mine in the world only scratches the surface of the earth’s crust

5. The world’s deepest mine is ______ deep • You would have to travel more than ____ times that distance – ____________ – to reach the Earth’s center… 3.8km 1600 Over 6000km

6. two Geologists use ____ main types of evidence to learn about the Earth’s interior • Direct evidence from _____________ • Indirect evidence from _____________ rock samples seismic waves

7. Evidence from Rocks • Geologists have drilled holes as much as _____ deep. These drills bring up _____________. • From these samples, geologists can make inferences about conditions ____________. • Also, sometimes the Earth blasts rocks to the surface from depths of more than 100km. These rocks provide even more evidence about ___________________ 12km rock samples deep inside the Earth’s interior

8. Evidence from Seismic Waves • Some seismic waves can pass only through _______ • Some seismic waves can pass through both _______________________ • Geologists use this knowledge to figure out ________________________ solids solids and liquids what is inside the Earth

9. The three main layers of the Earth • The Crust: ______ thick • The Mantle: ______ thick. • The Core: ______ thick 5-70km 2867km 3482km

10. The Crust There are two types of crust: _________: 10-70km thick ________: 5-10km thick Continental Oceanic

11. Continental Crust Continental crust varies in thickness, depending on whether or not it has been ___________________ folded into mountains

12. Continental CrustWhat’s it made of? • Continental crust is mainly made of … Granite!!! It’s light, only ____ lb/ft3 168

13. Oceanic CrustWhat’s it made of? • Oceanic crust is made of … Basalt!!! It’s heavy, at ____ lb/ft3 188

14. The many faces of basalt

18. The Lithosphere • The main characteristic of the lithosphere is that it is ________ • When it gets put under stress through ________________, it cracks and breaks • We experience this as an ___________ brittle plate tectonics earthquake

19. The Lithosphere • It is made of the ______ and the upper, rigid portion of the _______ crust mantle

20. The Mantle • The layer below the crust is called the _______ • The top part of the mantle is ______ like the crust and is part of the ____________ • The rest of the mantle is ________. This means it can flow, kind of like a super thick _______ mantle brittle lithosphere plastic liquid

21. The Asthenosphere • Just Lithosphere Asthenosphere Just as the __________ is rigid, the ____________ is _______ Plastic means that it can _____ and doesn’t _____ or break when _________ Although it’s plastic, it is still ______. If you kicked it, you’d stub your toe… plastic flow crack stressed solid

22. Examples of plastic things: glaciers

23. Tar

24. The Core • The Core is made mostly of the metals ____ and _______, and has ____ layers. • A ______ outer core, and a ______ inner core iron nickel two liquid solid

25. The layers of the Core • The outer core is a layer of _____ material that surrounds the ___________ • Despite _________________, the outer core is liquid • The inner core is a dense ball of __________ • In the inner core, extreme pressure _______ the atoms of iron and nickel so much that they cannot _________________________ liquid solid core enormous pressure solid metal squeezes spread out and become liquid

26. The Core and the Earth’s magnetic field • Scientists think that _________ in the ________________ create Earth’s ___________ • Because the Earth has a ______________, it acts like a _______________ movements liquid outer core magnetic field magnetic field gigantic magnet

27. This magnetic field protects us from __________________,and allows _______________ cosmic radiation life to exist