Structure of the Earth

1. Structure of the Earth Chapter 3

2. Section 1 Layers of the Earth • Objectives: • Describe and compare the crust, mantle, and core • Describe the structure of the lithosphere • Explain why matter within the asthenosphere moves • Make a model of the earth and its layers

3. Skills Warm-up • Layer by Layer • List different objects that are made up of layers. • Classify them based on number, type, and thickness of layers. • Do most of the objects contain soft or hard centers?

4. Earth’s Interior • Earth’s surface is made up of ______, ______, and _______ • At one time, people thought earth might be ___________ • In 1864, Jules Verne wrote “Journey to the Center of the Earth” • What do you think is between earth’s surface and its center?

5. Earth’s Interior • What would you find if you could bore a hole deep into the earth until you reached its center? • 1. The _________ __________of the materials changes as you go __________ • 2. Materials increase in ________ as you go __________ • 3. __________ and _________ increase with depth, but at different rates • The way that these factors ________ in the earth’s interior produces ________ with different ________ __________ and different ________ __________

6. Layers of the Earth • 3 Main Layers based on ___________ properties: • ________ – outermost layer of the earth • ________ – middle layer of the earth • ________ – innermost layer of the earth

7. Activity • Watch parts of Journey to the Center of the Earth

9. Chemical Makeup of Layers • From _________ to _________: • Crust – contains rocky ________ (silicon/oxygen compounds) rich in _________ (Al), _______ (Fe), and ___________ (Mg) • Thickness varies from _______to _______ • Mantle – dense, mostly _____ and ____ _________ • Makes up ________ of Earth’s volume • Makes up ________ of Earth’s mass • Core – very dense, mostly two metals: ___ and ___ • Makes up ________ of Earth’s mass • Makes up ________ of Earth’s volume

12. Physical Makeup of Layers • 3 Main Layers based on ___________ ___________: • The _____________includes the crust and outer mantle – it is strong, cold and rigid • The _____________is just below in the mantle - it is hot, semi-liquid, and easily deformed (plasticity) • The ______________(mantle) below the asthenosphere – very strong and rigid because temperature isn’t high enough

13. Physical Makeup of Layers • ______ ______– liquid • Temperature overcomes pressure • Circulation of molten Fe is source of magnetic field? • ______ ______– solid • Very high pressure overcomes high temperature

14. Physical Properties of Layers • ____________________ deep inside the earth are ______ __________to melt the silicates and other substances that make it up • But, most of the earth’s interior is not ___________ • Why????

15. Physical Properties of Layers • _________ inside the earth offset the high temperatures • _______ pressures will not allow the earth’s matter to _______

17. Physical Properties • _________between __________and ________varies with depth of each of earth’s layers • Depending on this balance, matter can be ________, ________, or ___ _________ • ___________– condition where the right balance of pressure and temperature makes _______ material _______ and ___________, but not completely liquid

18. Questions So FarAnswer the following 10 questions on a sheet of paper and hand them in at the end of class (use your guided notes) • 1. How thick is the crust and what does it contain? • 2. What materials does the mantle contain? • 3. How much of the earth’s volume does the mantle make up? How much of the earth’s mass? • 4. Which layer is more dense, the mantle or the core? (Remember D = M/V) • 5. What materials account for the density of the earth’s core?

19. Questions So Far • 6. Based on their characteristic physical properties, what are the 5 zones of the earth? • 7. What does the lithosphere include? • 8. What is the hot, soft, and flowing condition of the asthenosphere called? • 9. What is the physical condition of the outer core? Why? • 10. What is the physical condition of the inner core? Why?

21. Skills Warm-up • Crust: • What objects besides the earth have crusts? • How are their crusts similar to and different from the earth’s crust?

22. Structure of the ____________ • Two distinct parts: • ___________ _______ • Less dense because of higher percentage of silicon and oxygen, has more aluminum • Contains rocks called rhyolite and granite • ___________ _______ • More dense and darker in color • Contains rocks called basalt and gabbro • Which varies in thickness more?

23. Movement in the ______________ • Material is ________ and ________ – like hot tar • Intense heat from Earth’s core causes this material to _____________ • Matter ______ as it heats, then cools and slowly _______ The result – ___________, a circular flow of matter that is very slow, but has important effects!

24. Living on Oceanic Crust • Most oceanic crust is covered with _________ • But many islands and the surface of some continents are made of oceanic crust • _________ __________ • ___________ • ___________ __________ (Idaho, Washington, Oregon) • Oceanic crust soil is not as ________ because of large amounts of _______ and ____________ • Can be used to grow _________, _________, and ____________ or to graze ____________

25. Hawaii . Iceland

26. Graphing Activity Temperature Changes in then Earth • Each student should complete the graphing activity using the data and the graph paper that I give out. • If it is not completed in class, it must be done for homework.

28. Plasticity Activity

29. Section 2 Studying the Earth’s Interior • Objectives: • Identify two types of seismic waves • Describe the movement of seismic waves • Explain how earth scientists make inferences about the earth’s core • Infer the characteristics of an object through indirect observation

30. Skills Warm-up • Boiling Over: • Without removing the cover from a pot cooking on the stove, how could you determine what was cooking inside? • How might your method of determining the pot’s contents be similar to the way scientists determine what is inside of the earth?

31. How do we know it’s hot in there? Studying the Earth How do we know that some parts are liquid and some are solid? How do we know what the chemical makeup is?

32. Studying the Earth • The interior of the earth _______ be observed _________ • Deepest mine is ___ ____ _______ • Deepest hole ever bored into the crust went down only ________ – still far from the mantle • Earth’s _________ does provide some clues • ________ _______(magma) from volcanoes is evidence for high temperatures inside the earth • But most knowledge has come from ________ ___________ of how _______ _________from earthquakes travel

33. Shock Waves • You have all probably experienced shock waves • Have ever hit a baseball or softball with a bat? • The vibrations or shock waves travel through the bat to your hands • Shock waves can also travel through the _______

34. Seismic Waves • ____________– sudden movements in the crust that can cause shockwaves • ________ _____– shock waves from an earthquake • can pass from one side of the Earth to the other • __________– instrument that detects seismic waves. • Located all over Earth’s surface • Scientists gain valuable information about the interior of earth by comparing the ________ and ________ _______of waves

36. Types of Seismic Waves • The two types most useful for studying the Earth’s interior are: • ____ _______travel in a _______________ movement of rock particles. Particles are squeezed together, then pulled apart. • ____ _______travel in an ______________ movement of rock particles. • S waves cannot travel through __________

38. Speed and Bending of Waves • _______ at which waves travel depends partly on the ________ of the rock it travels through • The higher the density, the ________ the speed • As a wave passes through the Earth and encounters rock types with different densities, its speed __________ • If a wave passes through rock layers at a slight _______, a change in speed can cause it to change _____________

39. Speed and Bending of Waves • Most seismic waves travel in a ________ path through the Earth. This curving is called _________ • When a wave passes into a rock of a different ________, its path may ______ sharply

40. Inferring from Seismic Waves • With knowledge of how seismic waves travel, scientists have: • Located the _________ between earth’s ________ • Inferred the ________/_________ __________ of layers

41. AndrijaMohorovicic • Croatian scientist • In 1909 he discovered the boundary between the earth’s ______ and _________

42. The Moho • _________ ___________– “Moho”, the boundary between the crust and the mantle. • At a depth of between ____and ____km below the surface, seismic waves suddenly ______ _____ • At this depth, rocks became much more ______, and probably of a different ________ ________

44. The Core • When an earthquake occurs, it sends seismic waves in ____ _______ • P and S waves are detected by ______________ • At a certain distance away from where the earthquake occurs starts a zone in which ____ _________can be detected • Called the _________ _______– caused by the Earth’s ________

45. The Core • Note that __________ __________ from the earthquake, only ____ ________ are detected. What does this tell you about the core? • It suggests that at least part of the core is _______ since no ____ ________ are detected • The size of the earth’s core can be calculated from the size of the _________ ________

47. Answer the following questions: • Where do the seismic waves from an earthquake go? • What happens as P waves strike the core? Why? • Which waves cross the core? • Which waves are detected in the shadow zone? • What can be used to calculate the size of the core?

48. Activity – How Does Matter in the Mantle Move