2.  Most earthquakes occur at Plate Boundaries  The deepest earthquakes occur at subduction boundaries

3.  The focus of an earthquake is the source, or where it originates.  The epicenter is the point on the Earth’s surface directly above the focus.

4.  P- Waves (elastic) – push and pull the ground Travel through solids, Liquids & gases  S-Waves (shear) – move the ground up and down. Only travel through solids

5.  L-waves (Rayleigh/Love waves)- rolling surface waves; arrive last Only travel through solids

7.  Seismographs record results on seismograms  The difference in arrival times of p and s waves= lag time Using lag time we can find the distance to the epicenter

8.  The further away the seismograph station, the greater the lag time.

9.  We need 3 seismograph stations to find the epicenter of an earthquake. With one, it could be anywhere on the circle. With two, it could be either two areas they touch. With three, its where they all meet!

10.  This is where the crust is under stress and potential energy is stored.

17.  Measure of how much energy is released.  Richter scale is used to plot, from 1 – 10, how strong an earthquake is.  Each increase in 1 equals 10 times more energy released.

18.  Used to record the distance (measured in km) from the seismograph station to the epicenter of an earthquake

20. Tsunami 1 Tsunami