Earthquake is one of the natural calamities. Its origin can be traced to the early days of earth formation. It is responsible for a lot of damage to living and non-living beings. For many centuries man didn’t know why earthquakes occur and how they occur and to what extent they would damage. He only felt that mother earth was angry with him and so caused the earthquake and he always feared it.It was left to Aristotle, the great Greek philosopher, to relate the phenomenon of earthquake to physical factors. According to Aristotle, when the air compressed within the arch escapes, it shakes some part of the land. This emission is called volcanic activity.When the volcano bursts, lots of lava, gas etc come out of the earth and fail out. This causes pressure and imbalance and results in producing earthquake waves in the surrounding areas. It was thus identified that volcanic activity is one of the reasons for earthquakes. The volcanic activity results in faulting. To fill up the new faults the movement of earth takes place.