The document defines and describes several types of natural disasters including tornadoes, volcanoes, wildfires, avalanches, earthquakes, and tsunamis. It explains that tornadoes are powerful windstorms with a visible funnel, volcanoes erupt due to tectonic plate movement or mantle plumes, wildfires spread rapidly through vegetation, avalanches involve a rapid flow of snow down a slope, earthquakes are caused by sudden energy release in the Earth's crust, and tsunamis are large ocean waves caused by underwater seismic events.