In a Nutshell
In simple terms, a hazard is a dangerous situation or event that carries a threat to humans. A disaster is an event that actually harms humans and disrupts the operations of society. Hazards will be considered disasters once they affect humans, but if they occur in an unpopulated area, they will remain hazards. A good example of this is an underwater volcano. If it explodes and humans are not affected, it remains a hazard. But if it affects a nearby population by destroying food sources and property on a large scale, it will be seen as a disaster.
The Whole Bushel
To classify something as a hazard, it must have the potential to be dangerous and harmful to humans. Hazards are a normal occurrence on our planet and cannot be avoided. Remember, a hazard has all the potential to be harmful, but won’t actively harm humans or our environment. For example, a hurricane in the middle of the ocean that is nowhere near to land could be a simple hazard. It is unlikely that it will ever affect humans on a large scale, running out of momentum before it reaches our shores. However, if that hurricane does make it to land, the destruction it would cause upon a town or city would be deemed a disaster. To classify something as a hazard is to acknowledge the threat to life, health, environment or property.
For a disaster to take place, the normal operations of a human community must be completely disrupted. We have many examples of natural disasters caused by earthquakes, tsunamis, and hurricanes. The damage must be widespread enough to alter the normal operations of the community affected. In modern society, the event of a disaster sparks an international involvement and nearby countries or states aid in recovery operations. Disasters are hazards that have become ‘active’, harming humanity in the process. A volcano eruption is the perfect example of a hazard that becomes a disaster. If the volcano is active, it will be deemed a hazard, but once it explodes and wreaks havoc on the nearby population, it is considered a disaster. Oil leaks can also be considered disasters as they affect the health of marine life in the ocean and threaten important food sources.
When people talk about hazards and disasters, you will often hear the term ‘natural’ thrown in. This refers to acts of nature, like earthquakes or tsunamis. They are the most common type of hazard/disaster, but there can also be man-made ones. For example, a chemical leak or the explosion of a power station could easily be disaster-type situations. Sometimes man-made structures add to the impact of a hazard and together they create an even bigger disaster. In Japan, a nuclear power station was damaged by an earthquake and exploded. The combination of a natural hazard and a man-made structure resulted in a massive disaster that killed people and destroyed property.