Take the Celiac Disease Quiz to learn the causes, symptoms, and treatments for the condition caused by an allergy to gluten, a digestive irritant found in many common foods. Read more: Celiac Disease (Celiac Sprue) Quiz: Test Your Digestive Disease IQ.
Natural disasters fall into three broad groups: 1. Those caused by movements of the Earth. These occur with the minimum amount of warning and include earthquakes, volcanic eruptions and tsunamis. They are difficult to predict and impossible to stop.
Impact events, proposed as causes of mass extinction, are when the planet is struck by a comet or meteor large enough to create a huge shockwave felt around the globe. Widespread dust and debris rain down, disrupting the climate and causing extinction on a global, rather than local, scale.