Earthquakes

An earthquake is a sudden movement of the Earth's crust caused by the release of energy stored in rocks. This energy travels in the form of seismic waves.

Most earthquakes occur at tectonic plate boundaries, where plates move due to the convection currents inside the Earth. According to the elastic rebound theory, an earthquake occurs when stress causes strain to build along a fault line, causing the rocks to break.

The point inside the Earth where the rocks break is called the focus. Seismic waves radiate outward from this point. The location directly above the focus on the Earth's surface is called the epicenter, where the shaking is strongest.

Buildings and bridges may collapse if they are not designed to withstand seismic activity. Additionally, earthquakes can cause gas line ruptures, leading to fires.

A strong underwater earthquake can also displace large amounts of water, generating massive waves that flood coastal areas, often resulting in tsunamis.

Scientists use a seismograph to measure earthquake activity. The device records seismic waves and helps determine the earthquake's magnitude.