What causes earthquakes?

The ground shakes because big rocks below move. They push and slip. Then houses may wiggle. It can feel scary. Grown-ups help keep everyone safe.

Earthquakes happen because the ground under us is not one solid piece. It is made of huge pieces that move very, very slowly. Sometimes two pieces get stuck, then suddenly slip. That sudden slip makes the ground shake, like when you push a stuck toy car and it jumps forward.

Earthquakes happen when tectonic plates, giant pieces of Earth’s outer shell, slowly push past or into each other. Their edges can get stuck. Pressure builds until the rocks suddenly slip along a crack called a fault, and shaking waves move through the ground. Fun fact: thousands of tiny earthquakes happen every day, but most are too small for people to notice.