1. Landforms Earthquakes

2. Mountains A mass of rock rising more than 600 meters above the surrounding land Relief

3. Fold Mountain formation

4. Appalachian Mountains

5. Rocky Mountains

6. Alps

7. Himalaya Mountains

8. Fault-Block Mountain formation

9. Fault Block Mountain Ranges are cause by a series of normal faults

10. Sierra Nevada Mountains, CA

11. Grand Tetons, WY

12. Wasatch Mountains, Utah

13. When the Earth SHAKES Earthquakes

14. Volcanic eruptions can cause earthquakes but most earthquakes are caused by FAULTING

15. The Elastic Rebound Theory was first proposed by American geologist Harry Fielding Reid after the 1906 San Francisco Earthquake

18. Seismic Waves are waves of vibration sent out in all directions from the FOCUS

19. Focus The point below the surface where the rock layers break and move Epicenter The point on the surface, directly above the focus. Where the greatest damage usually occurs

20. Measuring Earthquakes

21. Charles Richter

22. Early Seismograph Newton’s First Law

23. Seismograph- the machine that measures earthquake waves

24. Seismogram – the recorded information of earthquake waves

25. The Richter Scale is based on MAGNITUDE

26. Each # is TEN TIMES larger than the # before it… Magnitude 1 Magnitude 2 Magnitude 3

27. Pennies as an example: Mag. 1 = 1 penny Mag. 2 = 10 pennies Mag 3 = 100 pennies Mag. 4 = 1000 pennies Mag. 5 = 10,000 pennies Mag. 6 = 100,000 pennies Mag. 7 = 1,000,000 pennies Mag. 8 = 10,000,000 pennies Mag. 9 = 100,000,000 pennies Mag. 10 = 1,000,000,000 pennies (that’s $10 million in pennies!!)

28. Richter Magnitudes Earthquake Effects Less than 3.5 Generally not felt 3.5-5.4 Often felt, little damage Under 6.0 Slight damage to buildings 6.1-6.9 Can be destructive to about 100 km 7.0-7.9 Major earthquake. Can cause serious damage 8 or greater Large earthquake. Serious damage for hundreds of km

29. Anatomy of a basic wave

30. Crest – the highest point on a wave (A, F) Trough – the lowest point on a wave (D, I) Amplitude – the distance between the midpoint & crest or trough Wavelength – distance between any two successive points on a wave Frequency - # of vibrations/ second (Hertz)

31. Types of Seismic Waves

32. Body Waves are waves that travel through the body of the earth Surface waves only travel along the surface of earth

33. Body Waves

34. Primary Waves AKA P-Wave Type of Longitudinal Wave Causes back and forth motion Follows the same direction as the energy transfer

35. P-Waves Type of COMPRESSIONAL wave (like sound) Will travel through solid, liquid or gas Travels at: 7.8 – 8.5 kps in mantle 7.2 kps in oceanic crust 3.5 kps in continental crust

36. Primary Wave

37. Secondary Wave AKA S-Wave Particle motion is perpendicular to direction of energy transfer Transverse or Shear Wave Will travel only through solids Travels 4 – 5 kps

38. Secondary Wave

39. Surface Waves

40. Love Wave

41. Recent evidence show s that L-Waves attenuate (gradually disappear) more slowly in older rock (eastern US) and more quickly in younger rock (western US) Two main types of surface waves: Love Wave Rayleigh Wave

42. Love Waves travel less than 4 kps Move side-to-side; like a snake Causes the most damage

45. Seismogram with the P- Wave, S-Wave and L-Wave

46. Seismic Risk in the US

47. Triangulation

48. Refraction

49. Refraction of seismic waves within the Earth

50. Zone between about 105 degrees & 145 degrees is the Shadow Zone

51. 105 degrees 145 degrees Focus