1. Chapter 5 Notes

2. Types of Stress ● Tension ● Pulls on the crust, stretching it thin ● Occurs when plates move away from one another ● Compression ● Rock is squeezed until it folds or breaks ● Occurs when plates push against one another ● Shearing (Tense) (Compress) (Shear)

3. Effects of Compression

4. Types of Stress ● Tension ● Pulls on the crust, stretching it thin ● Occurs when plates move away from one another ● Compression ● Rock is squeezed until it folds or breaks ● Occurs when plates push against one another ● Shearing ● Rock is pushed in two opposite directions ● Can cause rock to break and slip apart

5. Kinds of Faults ● Normal Faults ● Fault is at an angle, one rock lies above the other ● Plates move away from one another ● Divergent Boundary   ● Reverse Faults ● Fault is at an angle, one rock lies above the other ● Plates move toward one another ● Convergent Boundary   ● Strike-Slip Faults ● Plates move past one another ● Sliding Boundary   http://earthquake.usgs.gov/lear ning/animations/animation.php ?flash_title=Normal+Fault+Flas h+Animation&flash_file=normal fault&flash_width=220&flash_h eight=320 http://earthquake.usgs.gov/lear n/animations/animation.php?fla sh_title=Thrust+Fault+Flash+A nimation&flash_file=thrustfault &flash_width=220&flash_height =320 http://earthquake.usgs.gov/lear n/animations/animation.php?fla sh_title=Strike- slip+Fault+Flash+Animation&fl ash_file=strikeslip&flash_width =240&flash_height=310

8. Kinds of Faults ● Normal Faults ● Can create Fault Block Mountains ● Created Owen’s Valley and the Sierra Nevada Mountains http://earthquake.usgs.gov/lear ning/animations/animation.php ?flash_title=Normal+Fault+Flas h+Animation&flash_file=normal fault&flash_width=220&flash_h eight=320

9. Kinds of Faults ● Reverse Faults ● Created the Klamath Mountains in Northern California

10. Kinds of Faults ● Strike-Slip Faults ● San Andreas Fault

11. 5.2 Earthquakes and Seismic waves

12. DO NOT WRITE DOWN - READ

13. Types of Seismic Waves ● Seismic wave: energy carried from an earthquake away from the focus ● P Waves (Primary Waves) ● Moves quickly. Compresses and expands the ground ● S Waves (Secondary Waves) ● Moves more slowly. Creates S waves. Shake ground side to side and up and down ● Surface Waves ● Waves that reach the Earth's surface

14. Measuring Earthquakes ● Mercalli Scale ● I – XII ● Richter Scale ● 1-10 ● Moment Magnitude Scale

15. Monitoring Earthquakes Earthquakes are monitored by seismographs A seismogram is the pattern of lines that is made from a seismograph

16. Locating Epicenters Scientists use seismic waves to locate an earthquake's epicenter Differences in wave speed give us clues to distance…

17. Finding an Epicenter Need seismogram readings station locations The time difference between a p-wave and s-wave can tell you how far away an earthquake occurred P-waves are fastest – first disturbance S-wave are slower – second disturbance Los Angeles

18. 1.Find the arrival times of the P wave and S wave 2.Use S – P graph to find the distance of the earthquake from each station. Steps to Locating Epicenters

19. Finding an Epicenter Figure out the time difference between the P-wave and S-wave. 50 seconds Use an S-P graph to determine distance from the epicenter 480 km Los Angeles

20. Finding an Epicenter We know the distance, do we know where the earthquake originated? 0 500

21. Finding an Epicenter We know the distance, do we know where the earthquake originated? 0 500

22. Need at Least 3 Seismograph Stations

24. 1.Find the arrival times of the P wave and S wave 2.Use S – P graph to find the distance of the earthquake from each station. 3.Draw circles around each station indicating possible earthquake location. 4.Where the circles intersect is the location of the epicenter. Steps to Locating Epicenters

27. Locating Epicenters

28. Pt. 1: 41 seconds between the P wave and S wave = 400 km Pt. 2: 51 seconds = 500 km Locating Epicenters

29. Pt. 1Pt. 2

31. 5.3 Monitoring Earthquakes

33. Instruments to Measure Faults We can monitor a faults movement – both vertical and horizontal movement Creep Meter - Horizontal Laser-Ranging Device - Horizontal - Vertical