1. Earthquakes. By: Laura Barjarow Chapter 12.

2. Earthquakes A movement or trembling of the ground that is caused by a sudden release of energy when rocks along a fault move

3. Seismograph. Earthquakes generate seismic waves which can be detected with a sensitive instrument called a seismograph. Instrument that records vibrations in the ground Seismogram- a tracing of earthquake motion that is recorded by a seismograph.

4. seismic waves. Body waves- in geology, a seismic wave that travels through the body of a medium. Surface waves- in geology, a seismic that travels along the surface of a medium and that has a stronger effect near the surface of the medium than it has in the interior.

5. Body waves. P waves- (primary waves, or compression wave); a seismic wave that causes particles of rock to move in a back-and-forth direction parallel to the direction in which the waves traveling; fastest traveling seismic waves and can travel through solids, liquids, and gases. S waves- (secondary waves, or shear wave); a seismic wave that causes particles of rock to move in a side-to- side direction perpendicular to the direction in which the wave is traveling; second-fastest seismic waves and can travel only through solids.

6. Epicenters. The point on earth’s surface directly above an earthquakes starting point, of focus. Focus- the location within earth along a fault in which the first motion of an earthquake occurs.

7. Locating epicenters.

8. How to Locate Epicenter. Get three different seismograph reading and plot them on a map. The point which all the circles meet is where the epicenter is.

9. Elastic Rebound Theory. Elastic rebound- the sudden return of elastically deformed rock to its undeformed shape. Two blocks of crust push against each other at a fault. Which causes stress but doesn’t move because of friction. As stress builds up at the fault, the crust deforms. The rock fractures and then snaps back into its original shape, causing an earthquake.

10. Tsunami’s A tsunami is a giant ocean wave that forms after a volcanic eruption, submarine earthquake, or landslide. Causes much destruction if it reaches land.