An earthquake is the shaking of Earth's surface caused by a sudden release of energy in the lithosphere, creating seismic waves that can range from imperceptible tremors to catastrophic events capable of destroying entire cities. These events occur naturally through geological faults, volcanism, and landslides, but can also be induced by human activities like mining, fracking, and nuclear testing, with the hypocenter (focus) being the rupture point and the epicenter the ground directly above it. Some of the most devastating examples include the 1556 Shaanxi earthquake in China (which killed over 100,000 people), the 1976 Tangshan earthquake (the deadliest of the 20th century with up to 655,000 fatalities), and the 1960 Valdivia earthquake in Chile, the largest ever recorded at a magnitude of 9.5. The effects of these events are far-reaching, causing ground shaking, soil liquefaction, and offshore quakes that can displace the seabed and trigger deadly tsunamis and landslides. To mitigate these risks, scientists focus on prediction, forecasting, and preparedness through seismic retrofitting and earthquake engineering, while the cultural impact of quakes has shaped myths and modern media—and similar phenomena, known as marsquakes and moonquakes, have even been observed on other celestial bodies.