The earth is full of molten substances, which are usually relatively stable. When the internal pressure is too large and unstable, it will eject from the weak part of the earth's crust. Earthquakes are the response of crustal rupture, and are generally called sources. The deeper the source, the smaller the magnitude and the smaller the crack, and the volcano will appear seriously.
Volcano is a common geological phenomenon on the earth. There is a "liquid zone" between the crust 100 ~ 150 km, in which there is a molten silicate substance containing volatile gas at high temperature and high pressure, that is, magma. Once it rushes out from the weak part of the earth's crust, a volcano is formed.
4. Earthquake, also known as ground motion and ground vibration, is a natural phenomenon in which the crust vibrates in the process of rapid energy release, and seismic waves will be generated in this process. The collision between plates on the earth has caused the dislocation and rupture of plate edges and plates, which is the main cause of earthquakes.