Earthquake, also known as ground motion and ground vibration, refers to the vibration of the earth's surface caused by the sudden release of slowly accumulated energy in the earth, which will produce seismic waves. It is a special form of crustal movement. But why does the earth's crust move and produce movements like earthquakes?
Earthquake – performance
When an earthquake occurs, the most basic phenomenon is the continuous vibration of the ground, which is mainly characterized by obvious shaking. People in the extreme earthquake area sometimes feel jumping up and down before they feel a big shaking. This is because seismic waves come from the ground to the ground, and longitudinal waves arrive first. S-wave then produces large amplitude horizontal shaking, which is the main cause of earthquake disaster.
Earthquake genesis
Japan earthquake
World earthquake distribution map