1. Earthquakes

2. How do we measure an Earthquake? We can measure Earthquakes using one of two main scales. We can measure Earthquakes using one of two main scales. –Richter Scale –Mercalli Scale

3. Mercalli Scale In 1902 Guiseppe Mercalli devised a scale for measuring the intensity of an earthquake by relating it to the amount of damage it caused. In 1902 Guiseppe Mercalli devised a scale for measuring the intensity of an earthquake by relating it to the amount of damage it caused. In 1931 seismologists modified his scale to adapt to modern American building standards. In 1931 seismologists modified his scale to adapt to modern American building standards.

4. IBarely felt IIFelt by a few sensitive people, some suspended objects may swing IIISlightly felt indoors as though a large truck were passing IVFelt indoors by many people, most suspended objects swing, windows and dishes rattle, standing autos rock VFelt by almost everyone, sleeping people are awakened, dishes and windows break VIFelt by everyone, some are frightened and run outside, some chimneys break, some furniture moves, slight damage VIIConsiderable damage in poorly built structures, felt by people driving, most are frightened and run outside VIIISlight damage to well built structures, poorly built structures are heavily damaged, walls, chimneys, monuments fall IXUnderground pipes break, foundations of buildings are damaged and buildings shift off foundations, considerable damage to well built structures XFew structures survive, most foundations destroyed, water moved out of banks of rivers and lakes, avalanches and rockslides, railroads are bent XIFew structures remain standing, total panic, large cracks in the ground XIITotal destruction, objects thrown into the air, the land appears to be liquid and is visibly rolling like waves

5. Finding the Epicenter We can use Mercalli’s modified scale to find the epicenter of an earthquake. We can use Mercalli’s modified scale to find the epicenter of an earthquake. Today’s activity is a dramatization based on an actual earthquake that occurred in Wattsville, California in 1971. Today’s activity is a dramatization based on an actual earthquake that occurred in Wattsville, California in 1971. The next few slides are recordings from a local radio station that had callers phone in observations that they could make from their location. The next few slides are recordings from a local radio station that had callers phone in observations that they could make from their location.

6. KWAT Radio

7. Caller A

8. Caller B

9. Caller C

10. Caller D

11. Caller E

12. Caller F

13. Caller G

14. Caller H

15. Caller I

16. Caller J

17. Caller K

18. Caller L

19. Caller M

20. Caller N

21. Caller O

22. Caller P

23. Caller Q

24. Caller R

25. Caller S

26. Caller T

27. Caller U

28. Caller V

29. Final Task Now that you are finished marking down the number on the Mercalli scale for each location you want to begin to connect similar numbers on your map. Now that you are finished marking down the number on the Mercalli scale for each location you want to begin to connect similar numbers on your map. Be sure to look over your map carefully and draw lines that contain each number. Be sure to look over your map carefully and draw lines that contain each number. SEE EXAMPLE Put a star where you think the epicenter would be located. Put a star where you think the epicenter would be located.