When an earthquake occurs, the most basic phenomenon is the continuous vibration of the ground, mainly the obvious shaking. People in the earthquake zone sometimes feel jumping up and down before they feel a big earthquake. This is because seismic waves travel from underground to the ground, and longitudinal waves arrive first. Shear waves then produce a large horizontal vibration, which is the main cause of earthquake disasters. 1960 during the Chile earthquake, the biggest shaking lasted for 3 minutes. The first disaster caused by the earthquake was the destruction of houses and structures, causing human and animal casualties. For example, in the 1976 Tangshan earthquake in China, 70% ~ 80% of buildings collapsed, causing heavy casualties. Earthquakes also have a great impact on the natural landscape. The main consequence is that there are faults and ground fissures on the ground. The surface faults of large earthquakes often extend from tens to hundreds of kilometers, and often have obvious vertical and horizontal offsets, which can reflect the characteristics of structural changes at the source (see the Houwei earthquake and the San Francisco earthquake). However, not all surface faults are directly related to the motion of the source, and may also be caused by the secondary influence of seismic waves. Especially in areas with thick surface sediments, ground fissures often appear at the edge of slopes, banks of rivers and both sides of roads. This is often due to topographical factors. Without support on one side, the topsoil is loose and cracked due to shaking. The shaking of the earthquake makes the topsoil sink, and the shallow groundwater will rise to the surface along the ground fissure, forming the phenomenon of sand blasting and water inrush. A big earthquake will change the local topography, or uplift or sink. Urban and rural roads are cracked, rails are twisted and bridges are broken. In modern cities, water, electricity and communication are blocked due to the rupture of underground pipelines and the cutting of cables. The leakage of gases, toxic gases and radioactive substances will lead to secondary disasters such as fire, poisoning and radioactive pollution. In mountainous areas, earthquakes can also cause landslides and landslides, which often lead to the tragedy of burying villages and towns. The collapsed rocks blocked the river and formed an earthquake lake upstream. 1923 During the Great Kanto Earthquake in Japan, a mudslide occurred in Kanagawa Prefecture, which went down the valley as far as 5 kilometers.