Earth’s Interior Section 1

1. Earth’s InteriorSection 1 Chapter 4 Plate Tectonics

2. Earth’s Interior Intro-duction • We never have been able to visually see into the center of the Earth. • The largest mine is in South Africa and is about 3.8 kilometers (2.4 miles) deep.

3. Earth’s Interior Finding Indirect Evidence • Scientists use indirect observation to observe the Earth’s interior. • Scientists know about the interior of the Earth from waves produced by earthquakes. • Seismic waves – waves produced by earthquakes.

4. Earth’s Interior Finding Indirect Evidence • The speed of the seismic waves tell scientists about the structure of the Earth.

5. Earth’s Interior Diagram From: revisionworld.co.uk

6. Earth’s Interior A Journey to the Center of the Earth • To begin a journey to the center of the Earth, you would need to travel through solid rock. • Temperatures and pressures would change as you travel towards the center.

7. Earth’s Interior A Journey to the Center of the Earth Temperatures • At first, the temperature around the surface is cool. Then temperatures increase rapidly for several miles and then increase slowly after that. • For every 40 meters you travel inward, the temperature rises 1ºC (33.8ºF).

8. Earth’s Interior A Journey to the Center of the Earth Pressure • The deeper you travel into the Earth, the greater the pressure. • Pressure – the force pushing on a surface or area

9. Earth’s Interior Chemical Layers of the Earth • You will travel through several layers as you travel through the Earth. • The Earth is made up of three main chemical layers. • crust • mantle • core

10. Earth’s Interior Diagram From: faculty.weber.edu

11. Earth’s Interior Chemical Layers of the Earth • Each layer has its own conditions and materials. Diagram From: eoearth.org

12. Earth’s Interior The Crust • Crust – a layer of rock that forms Earth’s outer skin • Very thin layer of the Earth. • Includes both the dry land and the ocean floor. • Thickest under high mountains and thinnest under the ocean.

13. Earth’s Interior The Crust • Oceanic crust is made of dense materials. • Continental crust is made of less dense materials. • 5-40 km thick • Made of oxygen, silicon, aluminum, calcium, iron, sodium, potassium, and magnesium

14. Earth’s Interior

15. Earth’s Interior

16. Earth’s Interior The Crust Crust

17. Earth’s Interior The Mantle • Mantle – layer of solid, hot rock • Made of oxygen, silicon, iron, and magnesium. • 2,900 km thick • 68% of Earth’s mass and 82% of Earth’s volume

18. Earth’s Interior The Mantle • Traveling farther into the mantle there is increasing temperatures and pressures.

19. Earth’s Interior The Crust Crust Mantle

20. Earth’s Interior The Core • The core makes up about 33% of the Earth’s mass but only 15% of the Earth’s volume. • The core is VERY dense. • Made of iron and nickel • Temperatures range from 3630ºF – 5430ºF (2,000ºC – 3,000ºC)

21. Earth’s Interior The Crust Crust Mantle Core

22. Earth’s Interior Physical Layers of the Earth • The Earth is made up of five main physical layers. • lithosphere • asthenosphere • mesosphere • outer core • inner core

23. Earth’s Interior Litho-sphere • The crust and the upper part of the mantle are very similar, very hard and rocky. • Lithosphere – the crust and the uppermost part of the mantle

24. Earth’s Interior The Crust Lithosphere (rigid) Crust Mantle Core

25. Earth’s Interior Astheno-sphere • Material in the mantel is softer and can bend, somewhat like plastic.

26. Earth’s Interior Astheno-sphere • Asthenosphere – the soft rock layer of the Earth that can flow slowly • The lithosphere floats on top of the asthenosphere. • Enormous heat and pressure allow this soft, solid rock to move.

27. Earth’s Interior The Crust Lithosphere (rigid) Crust Asthenosphere (plastic) Mantle Core

28. Earth’s Interior Meso-sphere • Mesosphere– the hard rock layer that makes up most of the mantle • Extreme pressure at this depth makes the rock very hard and unable to move like the asthenosphere.

29. Earth’s Interior The Crust Lithosphere (rigid) Crust Asthenosphere (plastic) Mantle Mesosphere (rigid) Core

30. Earth’s Interior Core • The core has two parts, an outer core and inner core. • Outer core – a layer of molten, liquid metal that surrounds the inner core • Inner core – a dense ball of solid metal

31. Earth’s Interior The Crust Lithosphere (rigid) Crust Asthenosphere (plastic) Mantle Mesosphere (rigid) Outer Core (liquid) Core Inner Core (solid)

32. Earth’s Interior Physical Layers of the Earth Diagram From: geophysics.ou.edu

33. Earth’s Interior Physical Layers of the Earth Diagram From: faculty.weber.edu

34. Earth’s Interior Physical Layers of the Earth Diagram From: spring.net

35. Earth’s Interior Physical Layers of the Earth Layers of the Earth Depiction

36. Earth’s Interior Earth’s Magnetic Field • Currents in the liquid outer core force the solid inner core to spin at a slightly faster rate than the rest of the planet. • The currents created by the outer core create the Earth’s magnetic field.

37. Earth’s Interior Earth’s Magnetic Field • The Earth acts like a giant bar magnet. • A compass will point to the Earth’s magnetic North pole.

38. Earth’s Interior Earth’s Magnetic Field Diagram From: glossary.oilfield.slb.com

39. Earth’s Interior Diagram From: cnx.org