Why Do Earthquakes Happen? - A Clear Scientific Overview Earthquakes occur because the Earth’s crust isn’t one solid piece. It is divided into tectonic plates that constantly move over a semi-fluid layer beneath them. As these plates shift, they often lock or jam, causing stress to build up. When the stress becomes too much, the rocks suddenly break— releasing energy as seismic waves. This sudden release of energy is what we experience as an earthquake. 📌 How Plate Movements Create Earthquakes