What are earthquake zones?
Scientists have learned that earthquakes occur in a number of definite zones, mainly where there are deep trenches in the ocean bed with groups of islands nearby, such as around the Pacific. In these zones, seismologists (people who study earthquakes) try to guess whether stress is building up underneath the surface. If the area has been dormant (quiet) for a long time, it may be that an earthquake is about to happen. They also use seismometers to detect the tiny shock waves that occur right before an earthquake. It is estimated that there are 500,000 detectable earthquakes in the world each year. Of these, 100,000 can be felt, and 100 of them cause damage.