Question

What is an earthquake? What are the two main situationa in which earthquake occurs?

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.

Answer 2

It is the shaking of the surface of the earth,resulting from the sudden release of earth's lithosphere that creates seismic waves.

situation when earthquake occurs:

1. volcanic eruption,tectonic movement in the earths's crust.
2. when rock underground suddenly breaks along a fault.