What causes earthquakes?
They are caused by the movement of plates, which collectively from the earth's crust.
These plates are of various size, and they are very slowly but constantly drifting underneath the earth's surface.
When they collide or drag, the pressure causes those plates to distort.
Eventually the pressure reaches its limit causing the plates to jump or crack in order to release its energy.
This creaates vibration at the surface, known as earthquake.
Japanese islands are located at the intersection of four plates, North American and Eurasia continental plates as well as Pacific and Philippine Sea plates.
It is for this reason Japan suffers from many earthquakes.
