1. Earthquakes!!!

2. I. Earthquakes: vibrations of the earth’s crust that is caused by the shifting of lithospheric plates

3. A. Stress builds up along a fault until it becomes so great that the plates suddenly grind past each other… EARTHQUAKE!!!

4. B. Magnitude: measures the amplitude of an earthquake’s wave 1. measured on the Richter scale a. 7 or above will cause widespread damage

6. a. The richter scale is a logarithmic scale: an increase of one point on the scale represents a factor of 10 of the waves amplitude

7. b. The difference between earthquakes with a magnitudes of 6 and 7 on the richter scale is only one, but the difference in the wave’s amplitude is 10x bigger

8. C. Mercalli Scale: measures the intensity of an earthquake or how strong it felt in a given location 1. subjective/opinionated 2. Roman Numerals I-XII

10. II. Types of faults A. Fault: Break in rock where rocks on either side of the break move

11. 1. San Andreas fault: caused by the Pacific plate sliding north along the North American Plate

12. 2. 3 types of faults a. Normal fault: hanging wall moves down relative to the foot wall

15. b. Reverse fault: opposite of normal fault; hanging wall moves up relative to foot wall (thrust fault: reverse fault at low angle)

18. c. Strike-slip fault: rock on either side of fault slides horizontally

21. Focus: Area along a fault at which slippage first occurs, initiating an earthquake

22. Epicenter: Point on the earth’s surface directly above the focus of an earthquake