1. EARTHQUAKES Definition 1.a shaking or vibration of the ground

2. Why? 1.breakage of the ground along a fault 2.elastic rebound theory

4. Anatomy of an earthquake 1.focus 2.epicenter 3.slip 4.seismic waves

5. Seismic Waves 1.measure with a seismograph

6. Seismic Waves 2.Types i.body waves (1)P-waves (2)S-waves ii.surface waves

10. Locating an earthquake

13. Earthquake magnitudes 1.Richter Scale i.logarithmic scale ii.the amount of energy released by an earthquake increases about 30 times for every increment

16. Earthquake magnitudes Mercalli Intensity Scale i.indicates destructiveness of an earthquake

18. Earthquakes and Plate Tectonics 1.shallow focus = divergent boundaries 2.deep focus = convergent

20. Earthquake Damage 1. 800,000 earthquakes per year 2. 100 magnitude 6 - 7 3. about every 5 years there is an earthquake of magnitude > 8 4. soils saturated with water behave like fluid i.gas lines and power lines break

23. Forecasting Earthquakes 1.seismic gaps and recurrence studies i.San Andreas fault moves every 100 - 150 years (last great earthquake in 1857, so when is the next one due?)

24. Forecasting Earthquakes 2. precursor studies i.accelerated land uplift ii.increased emissions of radon from wells iii.groundwater levels rise iv.animal behavior