These interactive simulations allow students to investigate four of nature's more violent phenomena: volcanoes, earthquakes, hurricanes, and tornadoes. Each simulation begins with a brief written tutorial describing the characteristics and destructive potential of these hazards. Users may then adjust the various factors affecting the occurrence of these phenomena (for instance, ocean temperature, humidity, and atmospheric pressure for hurricanes) and observe the results. These simulations are related to the film National Geographic film "Forces of Nature"; other links provide access to lesson plans designed to accompany the film and to a list of locations where the film can be seen. There are also links to a preview of the film, fast facts, stories about famous natural disasters, and a glossary.