Lesson 10-13 Study Guide Answers

1. Lesson 10-13 Study Guide Answers

2. 1. Earthquake: • The shaking a vibrating of the earth caused by a sudden release of energy that comes from the movement of the crust. • 2. Crust: • The outermost layer of the earth. • 3. Fault: • A fracture in the Earth’s crust where there is tectonic movement.

3. 4. Mantle: • The layer of the earth that lies beneath the crust. • 5. Epicenter: • The point on the surface of the earth directly above the focus of an earthquake. • 6. Seismologist: • A scientist who studies earthquakes.

4. 7. Focus: • The point where the wave of an earthquake travels outward in all directions. • 8. Seismograph: • An instrument that detects, records, and measures the vibrations produced by an earthquake. • 9. Seismogram: • The record made by a seismograph; the paper on which earthquake waves are recorded.

5. 10. Seismic Waves: • Earthquake waves. • 11. Aftershock: • An earthquake wave that follows the main shock of an earthquake. • 12. Plate Tectonic Theory: • The theory that the surface of the Earth is made up of a patchwork of rigid plates which float in slow motion of top of the Earth’s hot, pliable interior.

6. 13. Ring of Fire: • A zone of intense earthquake and volcanic activity that encircles the Pacific Ocean basin where the Pacific Plate slides past or collides with adjoining plates. • 14. Magnitude: • The amount of energy released at the source of an earthquake. • 15. Intensity: • The amount of damage done by an earthquake.

7. 16. Compare the speed that P-waves and S-waves travel. • P-waves travel faster than S-waves. • 17. What amount of time does each small mark on a seismogram represent? • 1 minute • 18. How can you use the information from seismograph stations to locate the epicenter of an earthquake? • Calculate the distance the earthquake is from 3 stations. The place where the distance from the 3 stations meets is the epicenter.

8. 19. How does the amplitude (swing) recorded on a seismogram relate to the magnitude of an earthquake? • The larger the amplitude recorded, the larger the magnitude of the earthquake. • 20. Describe the movement of a P-wave. • Push-pull or front to back • 21. Describe the movement of an S-wave. • Side to side

9. 22. What is another term for a Primary (P) Wave? • Compressional Wave • 23. What is another term for a Secondary (S) Wave? • Transverse Wave • 24. What is the difference between a seismograph and a seismogram? • A seismograph is the instrument used to measure the waves of an earthquake, but a seismogram is the actual recording made by the seismograph.

10. 25. How can the variable of distance affect vibrations recorded by a seismograph? • The closer the seismograph is to the epicenter, the larger the amplitude of the waves will be. • 26. List as many differences as possible between S-waves and P-waves.

11. 27. Which waves arrive first at a seismograph station? • P-waves • 28. Explain why seismic waves might reach one seismograph station before they reach another seismograph station if the waves are coming from the same earthquake. • One station might be closer. The closer the station is to the epicenter, the sooner the waves will reach the seismograph station. The p-waves will be recorded first.

12. 29. How would you know which seismograph station was closest to the epicenter of an earthquake? • Look at the seismogram. The seismograph that records waves first will be the one that is the closest to the epicenter.