Answer:
1.Earthquakes are usually caused when rock underground suddenly breaks along a fault. This sudden release of energy causes the seismic waves that make the ground shake. When two blocks of rock or two plates are rubbing against each other, they stick a little. ... When the rocks break, the earthquake occurs.
2.Earthquakes. Most tsunami are caused by large earthquakes on the sea floor when slabs of rock move past each other suddenly, causing the overlying water to move. The resulting waves move away from the source of the earthquake event.
3.The main importance in determining the epicentre is so that the fault that ruptured causing the earthquake can be identified.
