Earthquakes
http://earthquake.usgs.gov/learn/kids/eqscience.php
http://earthquake.usgs.gov/learn/facts.php
http://geography.about.com/cs/earthquakes/a/ringoffire.htm
http://earthquake.usgs.gov/learn/topics/richter.php
http://environment.nationalgeographic.com/environment/natural-disasters/forcesof-nature/
http://science.howstuffworks.com/nature/natural-disasters/earthquake.htm
http://www.thetech.org/exhibits_events/online/quakes/seismo/
http://vulcan.wr.usgs.gov/Glossary/Seismicity/what_causes_earthquakes.html
http://news.nationalgeographic.com/news/2003/11/1111_031111_earthquakeani
mals.html
http://pubs.usgs.gov/gip/earthq1/predict.html
http://earthquake.usgs.gov/learn/topics/richter.php
http://geography-site.co.uk/pages/physical/earth/cause.html
http://www.msnbc.msn.com/id/7807001/ns/technology_and_science/t/whatcauses-earthquakes/#.UPcDJCc1law
http://www.tjhsst.edu/~jlafever/wanimate/Wave_Properties2.html
http://earthquake.usgs.gov/learn/animations/
http://www.exploratorium.edu/faultline/index.html
Volcanoes
http://http://www.learner.org/interactives/volcanoes/entry.html
http://http://pubs.usgs.gov/gip/volc/types.html
http://http://volcanoes.usgs.gov/hazards/gas/index.php
http://http://geography.about.com/cs/earthquakes/a/ringoffire.htm
http://http://environment.nationalgeographic.com/environment/naturaldisasters/volcano-profile/
http://http://pubs.usgs.gov/gip/volc/text.html
http://http://geology.com/volcanoes/vesuvius/
http://http://environment.nationalgeographic.com/environment/naturaldisasters/forces-of-nature/
http://http://earthobservatory.nasa.gov/Features/Volcano/
http://http://dsc.discovery.com/convergence/supervolcano/interactive/interactive.h
tml
http://http://www.ussartf.org/volcanoes.htm
http://http://environment.nationalgeographic.com/environment/naturaldisasters/volcano-profile.html