Practice Quiz 3 Answer Key available on website Not responsible for errors! This is a ROUGH DRAFT of a type of test. Some question numbers may be missing. Look at the Geode disk also! Take practice quizzes on the textbook website. (Login ID required from the front of your text) Chapter 9 relative vs numerical or absolute dating relative age principles: superposition, horizontality, cross-cutting relationships, unconformities (3 types) fossils – types of fossils Fig. 9-11 and conditions favoring preservation geologic time scale: how divided? radiometric dating: alpha decay, beta decay, ½ life how to calculate age using % parent and daughter data (chart provided) oldest rocks on earth ways to assure good radiometric age Chapter 10 Figures: 10.2, 10.4, 10.7, 10.8, 10.9, 10.10, 10.15, 10.18, 10.19, 10.20, Box 10.2-B, Terms: See page 293 for chapter page numbers that cover these topics anticline, syncline, basin, dome, brittle deformation, differential stress, compressional stress, tensional stress, strain fault, fold, force, graben, normal fault, reverse fault, strike slip fault (transform fault), strain, stress Questions pg. 293: 4, 6, 10, 11, 13, 14, 15, 17, 19, 20 Chapter 11 Figures: 11.2, 11.5, 11.9, 11.1, 11.13, Table 11.3 caption, Box 11.2, 11.20, 11.26, 11.28, Box 11.3-E&F Terms: aftershock, foreshock, body wave, surface wave, P wave, S wave, elastic rebound, epicenter, focus, fault, fault creep, liquefaction, magnitude, Richter scale, seismic gaps, seismic sea wave, seismograph (gram), tsunami, Wadati-Benioff zones Questions pg. 322: 4, 5, 6, 7, 8, 10, 12, 14, 15, 17, 21, 23, 25 Chapter 12: Pages 326 to 334. Be able to recognize the layers of the earth, different properties – density – and how the models are made: Earth’s interior has been modeled by looking at meteorites, mantle xenoliths, other planets, seismic wave recordings, heat flow, volcanoes, tectonics, earthquakes, and earth’s magnetic field. These all have contributed in some way to the model. Figures: 12.1, 12.6, 12.10 Terms:: See page 346: asthenosphere, llithosphere, outer core, inner core, crust, mantle, Moho, P and S wave shadow zones Questions pg. 346: 2, 4, 9 1. Identify the type of stress indicated in each diagram by selecting the correct respone. (Stress diagram, Copyright © Prentice Hall, Inc.) For each item below, place the correct letter in front of the type of stress illustrated. ________compressional stress ________tensional (extensional) stress ________ shear stress 4. 5. After erosion, an anticline will have the __________ rocks exposed at the center: a. younger b. older Identify the type of fold indicated by selecting the correct response: For each item below write the letter in front of the structure which labels the correct part of the image. _____overturned fold _____symmetrical syncline _____asymmetrical anticline _____symmetrical anticline 6. Which of the following is NOT a difference between an “anticline” and a “syncline,” when comparing the two different types of folds? a. anticlines "open" downward, whereas synclines "open" upward anticlines have older rocks in their middle (core) zone / synclines have younger b. rocks in their middle (core) zone c. the two types are inverted relative to each other d. anticlines "open" upward, whereas synclines "open" downward 7. Identify the type of fault illustrated by selecting the correct response. _______ strike-slip fault B (low angle thrust fault Note: Did not discuss this one in class Reverse) _______ reverse fault _______ normal fault 8. Which of the following is the best explanation of the difference between a normal and reverse fault? CHECK ALL that are correct. a. b. c. Normal faults are usually associated with divergent plate boundaries and tensional stress, whereas reverse faults are usually associated with convergent plate boundaries and compressional stress. Reverse faults are left lateral and normal faults are right lateral slip. Normal faults are defined by the hanging wall block moved up relative to the footwall block; reverse faults are defined by the hanging wall block moved down relative to the footwall block. 9. The deformation of rock layers can result in old rocks lying on top of younger rocks so that the Law of Superposition can not be applied. a. True b. False 10. An earthquake’s source of energy is located at the _____________, but the location at the land surface above that point is called the ______________. a. b. c. d. epicenter, focus focus, epicenter fault, slip primary, secondary 11. Match the following basic earthquake terms with the appropriate description: _____ fault creep A. a tremor or smaller earthquake that occurs after a main larger earthquake __B___ elastic rebound B. a “snap back” action – the cause of earthquakes _____ aftershock C. the location on the surface of the earth, above which the point of rupture occurred _____ foreshock D. the source point from which all earthquake energy radiates _____ fault E. slow and gradual displacement along a fault, usually resulting in little earthquake activity _____ epicenter F. a tremor or smaller earthquake that precedes a main larger earthquake _____ focus G. large fractures in the Earth along which rocks are moved and/or displaced, causing earthquakes 12. Which of the following best describes “elastic rebound” theory of earthquakes? As an earthquake occurs, the elastically deformed rocks along the fault a . spring back to their original shape as much as possible Just after the earthquake occurs, the elastic rocks along the fault spring b. forward, then backward. Just before an earthquake occurs, the elastic rocks along the fault spring c. forward, then backward. d. As an earthquake occurs, the plastically deformed rocks along the fault gently glide back to their original shape as much as possible. 13. Which of the following is true about P and S waves? a. P waves are the faster waves that arrive at seismographs first, before S waves b. P waves are the secondary waves that push and pull as they travel from the earthquake focus c. P waves are the slower waves that arrive at seismographs after S waves d. P waves and S waves always arrive together as pairs. 14. Which is correct regarding P and S seismic waves? a. S waves travel through solids, but P waves travel through liquids. P and S waves travel through liquids, but S waves do not travel through b. solids. P and S waves travel through liquids, but P waves do not travel through c. solids. d. P waves travel through solids, whereas S waves do not. 15. Using this earthquake travel-time graph, determine the approximate distance that this station is from the epicenter of an earthquake if the difference between first P and first S waves arrivals is 5 minutes. a. 700 miles b. 1000 miles c. 1500 miles d. 2000 miles Using the chart and calculated distance from the previous question, if the first P wave arrived at 10:28 am, what time did the earthquake occur? a. 10:17 b. 10:22 c. 10:34 d. 10:39 16. Earthquakes occur most frequently associated with ___________. a. areas of current tectonic plate margins b. areas of current continental margins c areas of current tectonic plate interiors d Volcanic regions 17. Which of the following are important reasons to study earthquakes? a. leads to the better understanding of tsunami (tidal waves) b. leads to a better prevention of property and life casualties c. leads to a realistic model of the Earth’s interior d. leads to the development and refinement of the plate tectonic theory e. all are important 18. ________ have the highest velocities. a. b. c. primary waves secondary waves surface waves 19. The ___________ is a direct measure of the distance from a seismic receiving station to the focus of a distant earthquake. a. time interval between the first P and S wave arrivals b. magnitude of the ground acceleration of surface wave passing a receiving station c. time elapsed between the first P wave arrivals from the first and last aftershocks d. time interval between the first P wave and the last surface wave 20. On earthquake distribution maps, the boundaries of the Earth’s tectonic plates are shown as zones of low seismic activity. a. true b. false 21. The mantle transmits P waves but not S waves. a. true b. false 22. The ________ of the Earth does not transmit S waves. a. outer mantle b. inner crust c. outer core d. inner core 23. Identify the type of seismic activity of the following by selecting the correct area on the map: I ______. shallow earthquakes in continental transform faults ______ Few detectable earthquakes ______ shallow focus earthquakes along a mid-ocean ridge ______ deep earthquakes in a subduction zone The mountains and valleys of the Basin and Range Province of western United States formed in response to __________. A) strike-slip faulting and hanging wall block uplifts B) reverse faults and large displacement, thrust faulting C) tensional stresses and normal-fault movements D) normal faulting and horizontal compression Brittle deformation would be favored over plastic deformation in which of the following conditions? A) high confining pressures B) warmer temperatures C) cooler temperatures D) shallow depths The Great Rift Valley of East Africa is characterized by __________. A) mainly reverse faulting as Africa collides with Arabia B) mainly anticlines and synclines (folding) as Africa collides with Madagascar C) mainly normal faulting as East Africa begins to rift apart D) mainly transform faulting along zones connecting the rift with the Red Sea Which one of the following statements concerning foci and epicenters is correct? A) The focus is the faulted point on the surface directly above the epicenter. B) The fault first cracks at the epicenter and breaks through to the surface at the focus. C) The epicenter is at the surface directly above the focus where the earthquake initiates. D) The earthquake starts at the focus and the rupture extends down to the epicenter. Which one of the following statements is correct? A) P waves travel through solids; S waves do not. B) P and S waves travel through liquids, but P waves do not travel through solids. C) S waves travel through solids and P waves travel through liquids. D) P and S waves travel through liquids, but S waves do not travel through solids. __________ have the highest velocities. A) Primary waves B) Secondary waves C) Surface waves D) Refracted S waves On a typical seismogram, __________ will show the highest amplitudes. A) P waves B) S waves C) surface waves D) body waves Which of the following foundation materials is most stable during earthquake shaking? A) bedrock B) unconsolidated moist soil C) water-saturate D) sand and mud Approximately how much more energy is released in a 6.5 Richter magnitude earthquake than in one with magnitude 5.5? A) 3000 times B) 3 times C) 300 times D) 30 times Energy is stored in rocks adjacent to the site of a future earthquake as __________. A) elastic strain B) plastic flow energy C) thermal energy D) plastic strain __________ refers to the tendency for a loosely consolidated foundation material to lose its internal cohesion and fail mechanically during earthquake shaking. A) Slip B) Liquefaction C) Brittle fracture D) Strain Earthquakes result from the sudden release of elastic strain energy previously stored in rocks surrounding a zone of fault movement. a b true false Tsunamis are caused by sudden displacement of large volumes of seawater. a b true false Because their energy dissipates rapidly in deep ocean waters, tsunamis seldom pose any danger to coastal areas far away from the causative earthquake. a b true false _________ are thought to be similar in composition to Earth's mantle. A) Shooting stars B) Metallic meteorites C) Cosmic gas clouds D) Stony meteorites Which of the following best characterizes how the diameter of Earth's core and the nature of the outer core were discovered? A) Crystalline iron was found in lavas erupted from the deepest known hot spots. B) By analysis of the P-wave and S-wave shadow zones. C) Because P-wave speeds are higher in the outer core than in the lower mantle. D) By using the ratio of iron meteorites to stony meteorites to deduce the relative diameters of the core and mantle. The __________ is the seismic discontinuity that forms the boundary between the crust and mantle. A) Moho B) D” layer C) lithosphere D) inner core Continental crust is generally thicker than oceanic crust. High rock temperatures enhance plastic deformation and flow in the asthenosphere and inhibit brittle fracturing needed for earthquakes to occur As P waves pass from the mantle into the outer core, velocities drop abruptly. On the blank spaces provided in the illustration below, fill in the names of the layers of Earth's interior that are labeled. Which level indicates the P-wave shadow zone? (a) __________ Which level indicates the zone where no direct P-waves are received? (b) __________ Which level indicates the zone where direct P-waves are received? (c) __________ The east coast of North America is a good example of a(n) __________ tectonic margin. a passive b active c transform d volcanic