Earthquake clouds sometimes occur before an earthquake. In Ancient Books of the 17th century, there are records of "The sky is fine after Sunday or sunset, while there are also records of fine clouds, such as the first line, great length, and great earthquake, in 1935, China's Longde County "re-building Longde County" in Ningxia contains "the sky is warm, the sky is clean, and sometimes black clouds are like a ray, Wan is like a long snake, horizontal sky, long and not scattered, it is bound to be an earthquake ".
Seismic cloud
The Research on seismic clouds in various countries is still a matter of recent years. China and Japan are in the leading position. The research on seismic clouds in China began after the Tangshan earthquake in 1976. There are more than 10 successful examples. First, the name "seismic cloud" is the former mayor of Nara, Japan, key Zhong sanlang. He has personally experienced the magnitude 7 earthquake in Fukuoka, Japan in 1956, in addition, when an earthquake occurs, you can see that there is a very strange cloud in the sky. as long as such a cloud appears, there will always be an earthquake, and it will be called an "seismic cloud ".
At present, the cause of the formation of the seismic cloud is still a mystery, and the earthquake itself is a very complex process, the seismic cloud is not an accurate prediction method.