1. Earthquakes

2. Berks County Earthquakes Sinking Spring – 12 /13/06 Felt at Wilson Southern 2.8 Spring Township 10/29/96 2.5 Spring Town. 2/1/96 2.3 and 4 more Whitfield 1/15/94 4.6 Sinking Spring 1/7/54 4.0

3. Millersville Seismograph

4. Earthquakes in Pennsylvania Web Sites Maps of PA Maps Maps of Eastern U.S. Maps Earthquake Map of U.S.Map Real-Time Seismograph from MillersvilleMillersville

5. Earthquake Photos Web Photos Italy 2002

6. Earthquakes Rocks bend, compress, and stretch from movement caused by forces in the Earth. Earthquakes can not be accurately predicted.

7. Earthquakes: Locations

8. Earthquake Vocabulary Shadow zone: a region that does not receive any earthquake waves Richter Scale – evaluates earthquake energy. Mercalli Scale – evaluates earthquake damage. Seismologist – scientist who studies earthquakes

9. Waves

10. Earthquake Vocabulary P-Wave = primary,arrive first, move in the direction of the wave. Secondary Waves = particles in rocks move at right angles to the direction of movement. Epicenter = The point on the Earth’s surface which is directly above the focus. Focus = The point in the Earth’s interior where energy is released.

11. Wave Forms

12. Earthquake Vocabulary Faults – once the elastic limit of rocks is passed, they break and move along surfaces called faults.

13. Earthquakes Magnitude- each level is 32 times more powerful; 8 is 32 x more powerful than a 7. A Seismograph measures Magnitude. Compression – a force that squeezes and compresses.

14. Vocabulary Tension – is the stress that causes stretching and elongation. Shear – is the force that causes slippage and sliding.

15. Faults Normal Faults – are caused by tensional forces. Reverse Faults – are caused by compression forces.

16. P-Waves of Earthquakes Primary Waves – the first waves that reach a seismograph.

17. Vocabulary Three seismographs are needed to locate an earthquake epicenter.