What is an Earthquake?

What is an Earthquake?

An earthquake is a sudden movement in the Earth’s crust which produces vibration. These vibrations may be detectable only by sensitive instruments called seismographs, or they may kill thousands as they destroy cities. Many earthquakes are caused when rocks move along faults. Severe earthquakes are most common near the edges of the “plates” in the Earth’s crust, such as around the Pacific Ocean, along the mid-Atlantic ridge and in the Mediterranean and South-West Asian regions. They occur when the plates move. Some earthquakes are caused by volcanic action, explosions and other factors. Earthquakes under the sea trigger huge waves called tsunamis.