Tornado A violent squall or whirlwind of small extent, as one of those occurring during the summer on the west coast of Africa.
Ash fall A rain of airborne ash resulting from a volcanic eruption.
Tsunami An unusually large sea wave produced by a seaquake or undersea volcanic eruption.
landslide The downward falling or sliding of a mass of soil, detritus, or rock on or from a steep slope.
Wildfire Any large fire that spreads rapidly and is hard to extinguish.
Earthquake A series of vibrations induced in the earth's crust by the abrupt rupture and rebound of rocks in which elastic strain has been slowly accumulating.
Avalanche A large mass of snow, ice, etc., detached from a mountain slope and sliding or falling suddenly downward.
Chemical contamination Contamination caused by chemicals
Flood The inundation of land that is normally dry through the overflowing of a body of water, esp a river.
Eruption When a volcanoe makes eruption.