Discussion on the essence of earthquake early warning

With the development of the national earthquake intensity quick report and early warning project, more and more “earthquake early warning (EEW)” has come into public view. There are more and more questions about “what is EEW” at home and abroad along with a variety of interpretations of EEW techniques. This paper discusses the progress of earthquake early warning in China, the essence and limitation of EEW. The essence of EEW is that the earthquake observation has entered a new stage of intensive observation, and EEW is the alert for application of earthquake quick report from minutes to seconds. Due to the limitations of early warning blind area and inaccurate estimation of earthquake intensity in the practical application of EEW, the understanding of earthquake scientists on the application efficiency of EEW technology has been deepened and changed. They gradually realized the importance of strengthening the alert function of EEW. At the same time, EEW is a complex social engineering. Scientists need to guide the public to understand the limitations of EEW in order to play the role of disaster reduction effectively.