1. 2/11/2016discuss the elastic rebound theory California Science Content Standards Covered: ► Plate tectonics operating over geologic time has changed the patterns of land, sea, and mountains on Earth's surface. As the basis for understanding this concept: ► 3D: Students know why and how earthquakes occur and the scales used to measure their intensities & magnitude

2. Terms Chapter 6 Define and write sentences or draw pictures 1. Earthquakes 2. Elastic rebound theory 3. Aftershocks 4. Focus 5. Epicenter 6. Pacific ring of fire 7. Fault zones 8. Seismograph 9. P waves 10. S waves 11. Surface waves 12. Magnitude 13. Microquakes 14. Mercalli scale 15. Intensity 16. Tsunami 17. Seismic gaps 2/11/2016discuss the elastic rebound theory

3. 2/11/2016discuss the elastic rebound theory Chapter 6 Introduction ► Ring of Fire Ring of Fire Ring of Fire ► Earthquakes 1 & 2 1212

4. 2/11/2016 discuss the elastic rebound theory Earthquakes Chapter 6 3D: Students know why and how earthquakes occur and the scales used to measure their intensities & magnitude Elastic Rebound Theory Anatomy of a Quake Epicenter, focus, seismic waves Fore, primary, aftershock Shallow, intermediate & deep focus

5. 2/11/2016discuss the elastic rebound theory Lecture 6.1 Discuss elastic rebound theory ► Elastic Rebound Theory  When a STRESS is applied, the road changes from its original form – ELASTIC DEFORMATION  When the RUPTURE relieves the STRESS, the ground under the road REBOUNDS and returns to its original condition  When the RUPTURE occurs, we feel the EARTHQUAKE

6. 2/11/2016discuss the elastic rebound theory Lecture 6.1 Discuss elastic rebound theory

7. 2/11/2016discuss the elastic rebound theory Explain why earthquakes generally occur at plate boundaries ► Slippage first occurs at the FOCUS ► The place on the SURFACE of the Earth under the focus is the EPICENTER

8. 2/11/2016discuss the elastic rebound theory Explain why earthquakes generally occur at plate boundaries ► 90% of earthquakes have a SHALLOW focus ► Intermediate and deep focus earthquakes (10%) occur 70 Km and DEEPER

9. 2/11/2016discuss the elastic rebound theory Explain why earthquakes generally occur at plate boundaries ► How does the depth of earthquakes explain the type of a boundary?

10. 2/11/2016discuss the elastic rebound theory Explain why earthquakes generally occur at plate boundaries ► 3 Major Earthquake Zones  Mid Ocean Ridges – mainly divergent  Eurasian-Melanisian Belt – mainly convergent  Ring of Fire – mainly convergent ► Each dot represents an EARTHQUAKE ZONE

11. 2/11/2016discuss the elastic rebound theory End Lecture 6.1

12. 2/11/2016discuss the elastic rebound theory Chapter 6 Section 2 Objectives 1. We will be able to compare the three types of seismic waves. 2. We will discuss the method scientist use to pinpoint an earthquake. 3. We will discuss the method most commonly used to measure the magnitude of earthquakes.

13. 2/11/2016discuss the elastic rebound theory Recording Earthquakes Lecture 6.2 ► Seismic waves are recorded on a seismograph ► 3 Major forms of waves recorded by seismograph  P Waves  S Waves  Surface Waves

14. 2/11/2016discuss the elastic rebound theory P Waves ► aka Primary Waves ► Travel the fastest ► Same direction as particle motion ► Travel FASTER through DENSER material ► Move through solids, gases and liquids

15. 2/11/2016discuss the elastic rebound theory S Waves ► aka secondary or shear waves ► SLOWER than P Waves ► Travel at RIGHT Angles to particles in motion ► CANNOT pass through liquid or gases

16. 2/11/2016discuss the elastic rebound theory How to find the epicenter ► Method: TRIANGULATION ► Must have three (3) seismographs ► Calculate the difference in P wave travel from all three

17. 2/11/2016discuss the elastic rebound theory

18. 2/11/2016discuss the elastic rebound theory Triangulation – Where is the epicenter located? This map shows how the epicenter of the Loma Prieta earthquake was determined using data from three seismic stations. The seismogram at Eureka, CA indicated that the epicenter was 478 km away (red circle). The green circle represents the distance of the epicenter (624 km) from Las Vegas. The blue circle represents the distance of the epicenter (702 km) from Elko, NV. The epicenter is determined by the intersection of all three circles near Santa Cruz, CA. This triangulation technique requires data from at least three seismic stations in order to determine the epicenter.

19. 2/11/2016discuss the elastic rebound theory Earthquake Measurement ► Magnitude is a measure of ENERGY RELEASED IN AN EARTHQUAKE  Measured by a RICHTER SCALE ► Intensity is the amount of DAMAGE an earthquake causes  Measured by the MERCALLI SCALE

20. 2/11/2016discuss the elastic rebound theory Lecture 6.2 ► Big Idea Question #2  What is the difference between intensity and magnitude? What scales are used to measure each? ► End of Chapter Questions  p. 112-113 #8-11

21. 2/11/2016discuss the elastic rebound theory TEST QUESTION: Circle on the diagram the location of the epicenter The seismogram in Pusan, Korea indicated that the epicenter was 549 km away (red circle). The green circle represents the distance of the epicenter (435 km) from Tokyo. The blue circle represents the distance of the epicenter (697 km) from Akita, Japan. The epicenter is determined by the intersection of all three circles in Kobe. This triangulation technique requires data from at least three seismic stations in order to determine the epicenter.

22. 2/11/2016identify changes in the earth’s crust that may signal earthquakes Essential Questions Chapter 6 Section 3 ► Describe the possible effects of a major earthquake on buildings ► Discuss the relationship of tsunamis to earthquakes ► List safety rules follow when an earthquake strikes ► Identify changes in the earth’s crust that may signal earthquakes

23. 2/11/2016identify changes in the earth’s crust that may signal earthquakes Describe the possible effects of a major earthquake on buildings ► Earthquake Damage ► Most injuries, result of collapsing buildings or falling objects. ► Types of damage – landslides, fires, broken gas and electric lines, flooding, and damage to dams ► The longer an earthquake last the more damage it causes

24. 2/11/2016identify changes in the earth’s crust that may signal earthquakes Describe the possible effects of a major earthquake on buildings ► Destruction to buildings and property ► Buildings are not designed to sway, walls can collapse, may tip over ► Type of ground, solid ground offers more support to buildings, loose soil can cause more swaying in buildings

25. 2/11/2016identify changes in the earth’s crust that may signal earthquakes Discuss the relationship of tsunamis to earthquakes ► Tsunamis ► Caused by underwater earthquakes, that either cause a landslide or faulting underwater. ► Faulting can change seafloor elevation, forcing the water to move up and down. ► Underwater landslide can cause this same up and down motion.

26. 2/11/2016identify changes in the earth’s crust that may signal earthquakes Discuss the relationship of tsunamis to earthquakes ► Tsunamis ► There is an early warning system to alert areas of tsunamis.

27. 2/11/2016identify changes in the earth’s crust that may signal earthquakes List safety rules follow when an earthquake strikes ► Earthquake Safety ► Before an earthquake  Be prepared – have canned food, bottled water, flashlights, batteries and a portable radio.  Plan what to do when a earthquake happens  Learn how to turn off gas, water and electricity to the house.

28. 2/11/2016identify changes in the earth’s crust that may signal earthquakes List safety rules follow when an earthquake strikes ► Earthquake Safety ► During an earthquake  Stay calm and get to a safe position  Indoors – protect yourself from falling objects.  Outside – stay away from tall buildings, power lines, bridges, or tunnels

29. 2/11/2016identify changes in the earth’s crust that may signal earthquakes List safety rules follow when an earthquake strikes ► Earthquake Safety ► After the earthquake  Check for hazards, always wear shoes, and avoid power lines

30. 2/11/2016identify changes in the earth’s crust that may signal earthquakes Identify changes in the earth’s crust that may signal earthquakes ► Earthquake warnings & predictions ► Animals behavior & past earthquakes used to predict future earthquakes, may be years off ► Fault stress measured to determine seismic gaps, to determine where a quake may happen. ► Instruments used to detect crust tilting, rock stress, water flow changes, electro magnetic changes to predict earthquakes. ► Decreases in P-wave speed may tell when a quake is coming. ► Most methods are not very reliable in predicting an earthquake