1. There are vast stores of heat energy within the interior of our planet, residual from what processes?

2. The surface of our planet was again and again struck by large meteorites in the distant past, but most of the scars of bombardment have been healed by what processes?

3. The Earth rumbles along, producing a steady diet of catastrophic upheavals for those that dwell on its surface. Those associated with the atmosphere and oceans include what?

4. The steady diet of catastrophic upheavals associated with the atmosphere and oceans are largely due to what?

5. Earthquakes and volcanoes arise from deep-seated processes that we will strive to understand. What supplies the energy for these phenomena?

6. There is rough topography on both the ocean floor and on the continents, which must withstand the flattening tendencies of what process?

7. Why have the continents been the most extensively studied of the global topography?

8. Why is the crust of the continents comprised of relatively low density rocks (relative to oceanic crustal rocks)?

9. Alfred Wegener, a meteorologist working in the 1920's, argued that continental drift has occurred based on what lines of evidence?

10. Why did the idea of large lateral motions of the continents, or Continental Drift, meet great resistance?

11. Sir Harold Jeffreys quibbled with the continental reconstructions, arguing that the fit is not really all that good, and there are 15 degree mismatches what had he overlooked?

12. What other notions were proposed in the search for a reconciliation to explain why the puzzle pieces of the continents fit together amazingly well?

13. In the late 1950s and early 1960s there began a revolution in the thought about the Earth, and the mobility of the surface. This is the time of the Plate Tectonics revolution. What observations underlay this hypothesis?

14. Another puzzle was that by the 1920s it was clearly established that some earthquakes occur deep in the mantle, down as deep as 700 km. Why was this particularly difficult to understand?

15. The deep events are also not uniformly distributed. Deep earthquakes occur in what limited regions?

16. How is the Earth's magnetic field produced?

17. For several hundred years, humans had exploited the general dipolar geometry of the Earth's magnetic field, as observed at the surface, primarily for what purpose?

18. From centuries of observations, it was recognized that the magnetic field of the Earth actually varies with time in what two ways?

19. In a layer of rocks at a given site, which have not undergone significant deformation, the orientation of the magnetic directions tend to flip direction with time. This remarkable observation provided what evidence about the Earth's magnetic field?

20. In the late 1950s and early 1960s, there was massive military sponsored mapping of the sea floor, particularly in the north Atlantic and north Pacific. This was largely for what purpose?

21. The main magnetic property measured was simply the intensity of magnetic. This revealed an amazing banded structure of ocean floor magnetization, with long, quasi-linear stripes of high or low magnetization. Key observations were made across the mid-Atlantic ridge, where it was recognized that the stripes parallel the submarine volcanic chain of the ridge, and are symmetric on either side of the ridge. The sequence of stripes bore strong resemblance to the unique bar code of magnetic field history seen vertically in layered rocks. This suggested that somehow the ocean floor has a horizontally varying age analogous to the vertically varying age of a layer of rocks. This led to what notion?

22. Compare the age of rock at a mid-ocean ridge where sea floor spreading is occuring and lateral rock at some distance perpendicular to the ridge.

23. Compare the magnetization of rock at a mid-ocean ridge where sea floor spreading is occuring and lateral rock at some distance perpendicular to the ridge.

24. How are sea floor spreading and Continental drift related?

25. What are SUBDUCTION ZONES?

26. The long chains of earthquakes in oceans and on the Pacific margin are now recognized to outline the major chunks of the Earth's surface that constitute what?

27. The entire surface of the planet is broken up into about how many major plates?

28. The record of the large-scale lateral motions of plate tectonics is well established, and it is the fundamental paradigm of the Earth Sciences, and guides most of our understanding of catastrophic processes such as earthquakes and volcanoes. The motions of the continents have also had what direct effects on life?

29. How can rock flow like a fluid on one hand, yet break brittly on the other?

30. Define Rheology

31. Why does rheology vary with depth?

32. Within the lithosphere, heat transports by conduction, how does this differ from convection?

33. The temperature increases almost linearly with depth in a conducting region, as in the lithosphere. Near what temperatures does the rheology of the rock begin to change very rapidly and become more ductile?

34. This softer region, which accommodates the motions of the lithosphere (The material flows readily, and does not translate laterally with the moving plate, but shears) is called

what?

35. While the lithosphere is pretty stiff for long-term forces, throughout much of the lower part of the lithosphere, the rock is too warm to be brittle for short term forces. This restricts brittle frictional sliding and earthquake faulting to what regions?

36. Deeper earthquakes require what special conditions?

37. What is the ultimate source of energy for driving earthquakes

38. Define the idea of faults,

39. Explain why not all faults have earthquakes.

40. When does a fault produce an earthquake?

41. More deeply buried rocks are more squeezed, so there is a general increase in frictional resistance with depth in the brittle zone. But the instability of friction proves to be very complex. The conditions under which frictional resistance is suddenly overcome by a gradually building shearing stress on the rock depends on what properties?

42. If we look at a map of where there are historically 'active' faults, meaning faults that have slipped in the most recent geological time interval called the Holocene, we find that California is criss-crossed with faults of many scales. There is a complex array of faults along the western margin of the state, what is the single most continuous fault?

43. Eastern California has large faults as well, primarily on the eastern side of the Sierra Nevada. Whereas the San Andreas involves horizontal shearing of the crust, with the western side moving northwestward relative to the eastern side, the faults in the Owens Valley involve what type of motion?

44. How fast are plates are moving typically?

45. We have good constraints on how fast various faults are accumulating deformation that will be released in earthquakes based on what evidence?

46. The edges of the plates are grinding past each other and must keep up with the overall motions. For most faults this is not a continuous sliding process but what type of process?

47. Why is it difficult to predict the future behavior of the most catastrophic earthquake events?

48. Define: Strike slip faulting.

49. Define: For faulting

50. What type of fault is usually found in regions of extension, where the crust is being pulled apart causing the upper block to move downward relative to the lower block (hanging wall downward relative to footwall). This includes mid-ocean ridges where sea floor spreading is taking place as well as continental rifts, like in Eastern Africa, where the crust is breaking apart.

51. What type of fault is usually found in regions of compression, where the surface is converging (the hanging wall moves upward relative to the footwall)? This is common in subduction zones and in places where continents are colliding.

52. The largest earthquakes tend to be thrust faulting events in subduction zones, and may be as large as what magnitude?

53. The 1906 San Francisco earthquake involved the rupture of a vertically dipping right lateral strike slip fault, which offset the west side toward the northwest relative to the east side. How was this sense of displacement readily observable?

54. Describe the basic idea of the Elastic Rebound Theory?

55. Most of the energy released from the volume of strained rock around the fault goes

where?

56. Some of the energy is released as seismic waves, which spread out through the rock, shaking the ground. Why is this energy of greater concern than the previous form of energy?

57. Why is there a tendency for humans to build in fault zone regions?

58. What is the key to understanding how earthquakes cause catastrophes?

59. What are the 2 fundamental seismic waves?

60. Which are faster, P waves or S waves?

61. In a P wave in rock, the particles oscillate in what direction?

62. An S wave in rock, involves shearing motions in what direction?

63. The P and S velocities are both controlled by what properties?

64. We study the seismic waves from earthquakes because they tell us about the source (the earthquake faulting process) and they tell us about the Earth. List 4 major results from the study of seismic waves.

65. The 1994 Northridge California caused about $30-40 billion damage and took over 60 lives. It was a magnitude 6.7 event. 2000 houses were destroyed or badly damaged, 40 apartment buildings collapsed, 500 apartment buildings had moderate to severe damage. What was the governments response to this disaster?

66. What are specialists in the design of structures to withstand the shaking induced by earthquakes called?

67. In order to study earthquakes we need to somehow record them. One approach is to describe the felt shaking and damage from an earthquake. This reveals the general location of the faulting and also suggests something about how much energy was released in the degree of damage. But there are many factors which influence the damage that have nothing to do with the faulting. Give an example.

68. What does a seismometer do?

69. How do most seismometers work?

.

70. Why is it necessary for the workings of the seismograph to be so intricate?

71. Why are P and S waves are called body waves?

72. Why do the ground motion recordings from earthquakes tend to be rather complex?,

73. How are surface waves formed?

74. What are the two main types of surface waves?

75. Of the two main types of surface waves which is faster?

76. What type of earthquake wave causes most of the damage?

77. What directions of shaking at the surface are seismometers designed to record?

78. How are seismometers designed and built to achieve this?

79. If we record the ground shaking at a site, and there is a nearby earthquake, what sequence of seismic waves will we see pass by the site?

80. Typically, the first thing we want to do is to determine the origin time and location of the source of the seismic waves. How is this done?

81. The arrival times of waves are used to locate the event, and once it is known where the event was. How is the size of the event then determined?

82. What is Intensity?

83. What is Magnitude?

84 What does it mean to say that Magnitude scales are all logarithmic?

85. What is the Richter scale?

86. What is the Seismic Moment?

87. What is the Moment Magnitude?

88. Why is the Moment Magnitude particularly useful for very large events?

89. Once we know how far each station is from the source, we can correct for the geometric spreading effects of propagation. The observed amplitudes of ground shaking can then be used to compute the magnitude or seismic moment. What else can be identified? determined? studied?

90. Why are there no S waves in th ideal case of a perfectly symmetric explosion?

91. What are wave propagation effects?

92. How is it possible to correct for wave propagation effects?

93. What type of faulting dominates on mid-ocean ridge systems?

94. As the outward propagating wavefront expands, it will encounter changes in rock properties of what two types?

95. At a boundary the seismic wave energy can have what three types of interaction?

96. Which of the above three types of interaction is commonly applied to the oil industry?

97. Describe the basic idea of the method used in searching for oil and mineral resources?

98. The P wave travel time curve is continuous out to distances about 1/4 of the way around the Earth (epicentral distances out to 90 degrees), but then there is a major shadow zone and discontinuity in the travel time curve. What does this reveal the presence of?

99. The S waves are also seen out to a distance of 90-100 degrees, but there the waves diminish and there is no discontinuous curve. What is this evidence of?

100. In the 1970s and 1980s seismologists began to systematically 'map out' the variations in three-dimensions. They drew upon the remote imaging procedures that had been introduced in the medical world, such as what?

101. Describe how CATSCAN tomography works.

102. Describe how Seismic Tomography works.

103. Most of the lateral variations in seismic velocity are the result of what?

104. Hot, slow seismic velocity regions are expected to be low density they will tend to rise, while cold, high seismic velocity regions will be high density and therefore do what?