Plate tectonics

• Blanchard, Donald L.  The ABC's of Plate Tectonics.   <http://webspinners.com/dlblanc/tectonic/ptABCs.php>.

• Blanchard, Donald L.  The Formation of Pangaea: The Making of a Supercontinent.  <http://webspinners.com/dlblanc/tectonic/pangea.php>.

• Geology: Plate Tectonics. The University of California Museum of Paleontology, Berkeley.  <http://www.ucmp.berkeley.edu/geology/tectonics.html>.

• WebDoGS Virtual Plates. <http://www.uky.edu/ArtsSciences/Geology/webdogs/plates/reconstructions.html>.

 Earthquakes and the Earth's Interior

• Hamilton, Rosanna L.  Earth's Interior & Plate Tectonics. 1995-1997. <http://www.solarviews.com/eng/earthint.htm>.

• Louie, J.  Earth's Interior.  <http://www.seismo.unr.edu/ftp/pub/louie/class/100/interior.html>.

• Louie, J.  Plate Tectonics, the Cause of Earthquakes.   <http://www.seismo.unr.edu/ftp/pub/louie/class/100/plate-tectonics.html>.

• National Earthquake Information Center.  USGS.  <http://wwwneic.cr.usgs.gov/>.

 Hurricanes

• National Hurricane Center. <http://www.nhc.noaa.gov/>.

 Tornadoes

• Tornadoes. NOAA.  <http://www.noaa.gov/tornadoes.html>.

 Volcanoes

•  Hawaiian Volcano Observatory.  U.S. Geological Survey.  <http://hvo.wr.usgs.gov/>.

•  Mount St. Helens. U.S. Forest Service.   <http://www.fs.fed.us/gpnf/mshnvm/volcanocam/>.

•  Volcanoes.com.   <http://www.volcanoes.com/>.

•  Volcanoes Page. Michigan Technological University.  <http://www.geo.mtu.edu/volcanoes/>.