A hazard is a situation that poses a level of threat to life, health, property, or environment. Most hazards are dormant or potential, with only a theoretical rik of harm; however, once a hazard becomes "active", it can create an emergency situation. A hazard does not exist when it is not happening. A hazardous situation that has come to pass is called an incident. Hazard and vulnerability interact together to create risk.
What is a tectonic event?
Tectonic events are the group name for such occurrences as earthquakes, volcanoes and tsunamis. They are called tectonic because they are all associated with earth movements of one kind or another.
Although it's a GCSE website there is some more information on: