An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth’s lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time.
The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. The word tremor is also used for non-earthquake seismic rumbling. At the Earth’s surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides.
In its most general sense, the word earthquake is used to describe any seismic event – whether natural or caused by humans – that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake’s point of initial rupture is called its hypocenter or focus. The epicenter is the point at ground level directly above the hypocenter.
Here are the top 20 biggest earthquakes in history.
| Rank | Event | Location | Magnitude |
| 1. | 1960 Valdivia earthquake | Valdivia, Chile | 9.5 |
| 2. | 1585 Aleutian Islands earthquake | Pacific Ocean, Aleutian Islands (now Alaska, United States) | 9.25 |
| 3. | 1730 Valparaíso earthquake | Valparaiso, Chile (then part of the Spanish Empire) | 9.2 |
| 4. | 1964 Alaska earthquake | Prince William Sound, Alaska, United States | 9.2 |
| 5. | 2004 Indian Ocean earthquake | Sumatra, Indonesia | 9.2 |
| 6. | 2011 Tōhoku earthquake | Pacific Ocean, Tōhoku region, Japan | 9.1 |
| 7. | 1737 Kamchatka earthquake | Kamchatka Peninsula, Russian Empire | 9.15 |
| 8. | 1837 Valdivia earthquake | Valdivia, Chile | 9.15 |
| 9. | 1575 Valdivia earthquake | Valdivia, Chile (then part of the Spanish Empire) | 9.0 |
| 10. | 1604 Arica earthquake | Arica, Chile (then part of the Spanish Empire) | 9.0 |
| 11. | 1707 Hōei earthquake | Pacific Ocean, Shikoku region, Japan | 9.0 |
| 12. | 1833 Sumatra earthquake | Sumatra, Indonesia (then part of the Dutch East Indies) | 9.0 |
| 13. | 1841 Kamchatka earthquake | Kamchatka, Russian Empire | 9.0 |
| 14. | 1952 Severo-Kurilsk earthquake | Kamchatka, Russian SFSR, Soviet Union | 9.0 |
| 15. | 1700 Cascadia earthquake | Pacific Ocean, US and Canada (then claimed by the Spanish Empire and the British Empire) | 8.95 |
| 16. | 1868 Arica earthquake | Arica, Chile (then Peru) | 8.9 |
| 17. | 1957 Andreanof Islands earthquake | Andreanof Islands, Alaska, United States | 8.85 |
| 18. | 1852 Banda Sea earthquake | Banda Islands, Indonesia (then part of the Dutch East Indies) | 8.8 |
| 19. | 1877 Iquique earthquake | Iquique, Chile (then Peru) | 8.8 |
| 20. | 1906 Ecuador-Colombia earthquake | Ecuador – Colombia | 8.8 |
| 2010 Chile earthquake | Maule, Chile | 8.8 |
