Earthquakes and killer waves
Everybody knows that during an earthquake the ground shakes, lots of buildings fall down and sometimes cracks appear in the earth.
Our planet is covered with a thick crust, which is cracked into more than twenty sections. These cracked sections are called tectonic plates and they are always on the move. They move very slowly, but with incredible power. An earthquake happens when they rub against each other or collide with each other.
Earthquakes happen in all parts of the world. But most of them are so small that we don’t notice them. Big earthquakes are really dangerous.