1. Seismic Waves and Scales

2. Natural vibrations of ground caused by movement along fractures in Earth’s crust. Earthquakes can cause major damage. EQ Destruction

3. Earthquakes correlate with plate boundaries. http://www.earthquakeusgs.org/wp-content/uploads/Map-of-major-earthquakes-in-the-world-1.jpg

4. Rocks fail when stress is applied too quickly or is too great. Faults are also likely places for earthquakes to occur. Resulting fracture(s) in the Earth’s crust along which movement occurs is called a fault. San Andreas fault zone, Carrizo Plains, central California. Photo by R.E. Wallace, USGS

5. Focus - point where earthquakes originates. Usually several km below the surface Epicenter - point on the Earth’s surface directly above the focus of an earthquake Which is usually more dangerous, a shallow focus EQ or a deep focus EQ?

6. Normal fault Bodies of rock are pulled from opposite sides. http://windupradio.com/earthquakes/causes.htm

7. Reverse fault When horizontal stress is exerted on a body from opposite sides. http://windupradio.com/earthquakes/causes.htm

8. Strike-slip fault Movement is horizontally past each other. http://windupradio.com/earthquakes/causes.htm

9. http://www001.upp.so-net.ne.jp/fl-fg/04_fault/04-01_normal_fault-jyougashima-810X540-060730DSC_0920.jpg http://structuralgeo.files.wordpress.com/2013/07/reverse-fault-zone-ketobe-knob-utah.jpeg http://geology.uprm.edu/Morelock/1_image/fltoffst.jpg

10. Vibrations are called seismic waves. There are 3 types of seismic waves: Primary waves Secondary waves Surface waves

11. PRIMARY or P-WAVES - squeeze and pull rocks in the same direction; can travel through solids and liquids

12. SECONDARY or S-WAVES - rocks move at right angles; an up and down wave; can only travel through solids

13. SURFACE WAVES - move in 2 directions; up and down and side to side; occur on surface of earth.

14. Most of the knowledge of the Earth’s interior comes from the study of seismic waves, which change speed and direction when they encounter different materials

15. Remember: P waves travel through solids and liquids S waves travel only solids Can P and S waves from an earthquake be detected everywhere on Earth? Seismic Waves

16. Richter Scale - used to describe the magnitude or energy released from an earthquake. Based on size of largest seismic wave generated by earthquake. Based on powers of 10, so a 9.0 EQ is 10 X more powerful than an 8.0 EQ! Modified Mercalli Scale - used to describe the intensity or damage from an earthquake.

19. http://cdn.sheknows.com/articles/crave/seismograph-machine.jpg

20. The difference in arrival times between the P wave and S wave (S-P Interval) can be used to determine the distance between the earthquake’s epicenter and the seismograph station. http://ohhs.ohsd.net/~brick/ear/earr_eq_ampl.htm What is the S-P Interval from this seismogram? 37 seconds Seismic Station: Raleigh, NC

21. http://ohhs.ohsd.net/~brick/ear/earr_eq_ampl.htm How far is the seismic station in Raleigh from the earthquake? 360 kilometers

22. http://www.yellowmaps.com/maps/img/US/blank-base/mjrcity.jpg Raleigh, NC = 360 km

23. Nashville, TN = 825 km http://www.yellowmaps.com/maps/img/US/blank-base/mjrcity.jpg Raleigh, NC = 360 km

24. Nashville, TN = 825 km http://www.yellowmaps.com/maps/img/US/blank-base/mjrcity.jpg Raleigh, NC = 360 km Buffalo, NY = 1200 km Where was the earthquake’s epicenter?

25. http://www.npenn.org/page/5063

26. Even with all the monitoring that occurs, earthquakes cannot be predicted. The variables involved are too involved and dynamic to find a correlation in data gathered to say without doubt when they will occur. The risk in the United States is varied and can be seen on this map.

38. Valdevia Chile, 1960 - Magnitude 9.5 1,655 people were killed. The quake triggered a tsunami that killed 61 people in Hawaii, 138 in Japan and 32 in the Philippines. The earthquake ruptured where the Nazca Plate dives underneath the South American Plate, on the Peru-Chile Trench.

39. Tsunami - Large waves generated by an earthquake that occurs in the ocean This photograph of the tsunami arriving on shore in Japan shows the vertical height of the wave. Note the crest which is a tree top level. That would make the height of the wave roughly 30 feet.

41. http://www.nytimes.com/interactive/2011/03/13/world/asia/satellite- photos-japan-before-and-after-tsunami.html

42. Warm Up: What is a geohazard? List as many geohazards as you can.

43. Definition: A harmful event caused by the earth Examples: 1. Volcanoes 2. Lahar (mud) flows 3. Earthquakes 4. Tsunamis 5. Landslides 6. Avalanches 7. Sinkholes 8. Flooding Where are you most likely to experience one?

44. http://www.earthquakeusgs.org/wp-content/uploads/Map-of-major-earthquakes-in-the-world-1.jpg

45. Definition: A harmful event caused by the earth Examples: 1. Volcanoes 2. Lahar (mud) flows 3. Earthquakes 4. Tsunamis 5. Landslides 6. Avalanches 7. Sinkholes 8. Flooding Which is the most dangerous? Which one are you most likely to die from?

46. Chances of dying from being struck by lightning? In in 2,320,000 Chances of being attacked and killed by a shark? 1 in 3,748,067 http://www.accuweather.com/en/weather-news/does-lightning-strike-men-or-w/51439 http://aquaviews.net/explore-the-blue/5-shark-attack/

47. Definition: A harmful event caused by the earth Examples:Chances of Dying: 1. Volcanoes1 in 80,000 2. Lahar (mud) flows? 3. Earthquakes1 in 131, 890 4. Tsunamis1 in 500,000 5. Landslides? 6. Avalanches1 in 9,300,000 7. Sinkholes? 8. Flooding1 in 30,000

48. Definition: A harmful event caused by the earth Examples:Assignment: 1. Volcanoes 2. Lahar (mud) flows 3. Earthquakes 4. Tsunamis 5. Landslides 6. Avalanches 7. Sinkholes 8. Flooding Create a Public Service Announcement in the form of a illustrated and descriptive poster, including the following components… Description (What is it?) Causes (Why does it happen?) Preparations (How can we as a society and you as an individual be prepared for one?) Survival (How can you survive one?)