Why do earthquakes happen?

Why and how are earthquakes happening?

The spot underground where the rocks break is called the focus of the earthquake. The place right above the focus is called the epicenter of the earthquake.

Earthquakes are usually caused when rocks underground suddenly break apart along a fault. This release of energy causes the seismic waves to shake the ground.

When two blocks of rocks are rubbing against each other, they stick a little. Rocks don't slide smoothly; the rocks catch on each other. The rocks are still pushing against each other, but not moving.

After a while, the rocks break because of all the pressure that builds up. When the rocks break, the earthquake occurs.

During and after the earthquake, the blocks of rock start moving, and they continue to move until the rocks are stuck together again.

So an earthquake occurs when two blocks of rocks are split apart along a fault.