Earthquakes are caused primarily by the sudden release of energy due to the movement of the Earth's tectonic plates. These plates are constantly moving but often get stuck at their edges because of friction. When the stress on these stuck edges overcomes the friction, the plates suddenly slip, releasing energy in the form of seismic waves that cause the ground to shake
. This process typically occurs along faults-fractures in the Earth's crust- where the rocks on either side accumulate elastic strain energy over time due to tectonic forces. When the strain exceeds the strength of the rocks, they break and slip suddenly, producing an earthquake. The point underground where the rupture starts is called the focus (or hypocenter), and the point on the surface directly above it is the epicenter
. Most earthquakes happen along tectonic plate boundaries, especially in regions like the Pacific "Ring of Fire," where plates collide, slide past, or pull away from each other. About 80-90% of earthquakes occur in this zone, which is also associated with volcanic activity
. Besides tectonic movements, earthquakes can also be triggered by other causes such as volcanic activity, landslides, human activities like mining, reservoir-induced seismicity, and underground explosions
. In summary, the main cause of earthquakes is the build-up and sudden release of stress along faults due to tectonic plate movements, resulting in seismic waves that shake the Earth's surface
