Earthquakes occur due to the sudden release of energy in the Earth’s crust, typically caused by the movement of tectonic plates along fault lines. This movement generates seismic waves, which cause the ground to shake. The **Richter scale** measures the magnitude of an earthquake, while the **Mercalli scale** assesses its impact on people and structures. Earthquakes can trigger secondary natural disasters like tsunamis, landslides, and volcanic eruptions. Preparedness and early warning systems are essential in mitigating the impact of these events. Understanding the science of earthquakes helps improve building codes and disaster response strategies to reduce loss of life and damage.