The document discusses key concepts related to earthquakes including: 1. Faults are cracks in the Earth's crust where rock rubs against rock, such as the San Andreas Fault. 2. Seismographs are instruments that record seismic waves, which are vibrations caused by earthquakes or other movements within the Earth. 3. The Richter Scale is used to measure the amount of energy released by an earthquake, with higher magnitudes causing greater damage to structures and buildings.

1. I. Fault: A crack in the Earth’s crust, where rock rubs against rock.

2. A. San Andreas Fault

3. C.

4. D. Dead Sea Fault

5. II. Seismograph: Instrument used to record seismic waves

8. http://tinyurl.com/8xpgdq

10. A. 1.0-3.0: Felt only by a few persons, especially on upper floors of buildings.

11. B. 3.0-6.0 : Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight.

12. C. 7.0+: Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations.

13. D. Arkansas is at risk of a major earthquake!

20. V. S, P, and Surface Waves http://www.kettering.edu/~drussell/Demos/waves/wavemotion.html

24. http://neic.usgs.gov/neis/eq_depot/2002/eq_021103/ak_seismic_waves.html