Are earthquakes scattered all over the world or do they seem to occur near each other ( in groups)?

Earthquakes tend to occur near one another in groups. This is due to the fact that most earthquakes are the result of tectonic activity as the Earth's plated collide and subduct beneath one another. These collisions create stress within the crust; once this stress grows too great, the crusts slip resulting in an earthquake. Therefore earthquakes tend to cluster around plat boundaries and rarely occur elsewhere.