1. Earth’s Interior Section 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).
A Journey to the Center of the Earth

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 Crust (rigid) 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 Crust (rigid) 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 Crust (rigid) 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