1 / 23

Earthquakes

Earthquakes. How they happen and what we can learn from them. What causes most earthquakes on Earth?. 1) Stress  pressure is applied to sections of rock in different directions 2) Strain  rocks deform from their original shape 3) Fracture  rocks break

olympe
Télécharger la présentation

Earthquakes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Earthquakes How they happen and what we can learn from them.

  2. What causes most earthquakes on Earth? 1) Stress pressure is applied to sections of rock in different directions 2) Strain rocks deform from their original shape 3) Fracture rocks break 4) Faulting rocks move along the break as they ‘snap’ back to their original shape

  3. Q1: The description of how earthquakes happen given on the previous slide is often referred to as… • Plate Tectonic Theory • General Relativity Theory • Special Relativity Theory • Elastic Rebound Theory • Mohorovicic Discontinuity Theory

  4. Elastic Rebound Theory

  5. Q2: Which option gives the correct name for each of the letters on the diagram? • A = Focus; B = Epicenter C = Fault • A = Epicenter; B = Focus C = Fault • A = Fault; B =Focus C =Epicenter • None of these A B C

  6. When energy is released from a focus, it propagates out from that point through the interior of the Earth as two different types of waves.

  7. When the P & S waves reach the epicenter, they produce surface waves, called…

  8. Q5: Which type of earthquake wave is able to pass through liquid layers of earth’s interior—thus helping us figure out earth’s structure? • P waves • S waves • Raleigh waves • Love waves

  9. How we know about earth’s interior: • Waves refract (thus changing the timing and positioning of their arrival) when encountering a different density layer. • S-waves cannot pass through the liquid outer core.

  10. Q6: What is this? • Richter Scale • Seismograph • EKG Device • Quakemeter • None of these

  11. A Siesmograph… • Uses inertia to measure the amount of shaking experienced. • 3 different ones needed to record shaking in all directions.

  12. Q7: A Siesmogram sheet shows that… • The p-wave arrives before the s-wave • The s-wave arrives before the p-wave • Both p & s waves arrive at the same time

  13. P-wave = primary wave—travels fastest S-wave = Secondary wave

  14. Q8: Since we know how fast each type of wave travels, the amount of time between the arrival of the p-wave and the arrival of the s-wave will indicate… • The magnitude of the earthquake • How far away the epicenter is located • The exact location of the epicenter • How destructive the earthquake was • How long the earthquake lasted

  15. Since you only can tell distance to the epicenter from once siesmograph, the only thing you can do is plot that value as a circle. At least three recording stations are needed to pinpoint the exact epicenter.

  16. Q9: How does a magnitude 7 earthquake compare to a magnitude 6 earthquake? • It is 2 percent stronger • It is 10 percent stronger • It is 31 percent stronger • It is 2 times stronger • It is 10 times stronger • It is 31 times stronger

  17. Richter Scale magnitudes are logarithmic values, thus increasing from a magnitude 6 to a 7 is actually 31 times greater in terms of energy. • The Richter Scale is a logarithmic scale of wave amplitude (meaning that going from a 6 to a 7 is a 10X increase in amplitude). M5 M6 M7

  18. Oakland, CA 1989

  19. Landers, CA 1992

  20. Liquefaction Niigata, Japan 1964

  21. Landslide caused by an earthquake: Turnnagin Heights,Alaska,1964

  22. Loma Prieta, CA 1989

More Related