CCTV News (Evening News): After the earthquake occurred, some people received warning reminders on their mobile phones about the arrival time and epicenter distance of the seismic shear wave. Why did you receive an earthquake warning? What should I do after receiving the warning message? Take a look at the interpretation of authoritative experts. Earthquake warning is not a prediction, but an alarm. According to experts, earthquake warning is not an earthquake prediction, but an alarm. Receiving the warning information indicates that an earthquake has occurred. It refers to the rapid issuance of a hazard warning to the area before the destructive earthquake wave has arrived after an earthquake, usually only a few seconds to several tens of seconds, which can provide the public with emergency response, shelter and escape time. Researcher Gao Mengtan from the Institute of Geophysics, China Earthquake Administration: This is mainly due to the construction of our national earthquake warning system. The earthquake warning system utilizes the principle of encrypting the network in earthquake prone areas. Once an earthquake occurs, using these dense networks, we can determine the size and location of the earthquake in a relatively short period of time, and calculate the intensity of its impact. We can calculate the intensity of different regions, and use electromagnetic waves to send warnings to various regions in a very short time. This type of warning time usually lasts for a few seconds, over ten seconds, or even more than 20 seconds. The warning content received by different regions varies, but the arrival time and epicenter distance of earthquake shear waves displayed in the warning information received by different people are different. Why is this? Gao Mengtan: From the principle of the current warning system, the duration of this warning is also limited in terms of the speed of earthquake wave propagation and its impact range. The reporter learned that the length of earthquake warning time depends on the distance between the area and the epicenter, and the closer the area is to the epicenter, the shorter the warning time. In general, near the epicenter, the time for providing early warning is almost zero, which means there is a warning blind spot. Seizing a few seconds or even tens of seconds to avoid danger, earthquake warning information can buy people a few seconds or even tens of seconds to avoid danger after an earthquake. What should we do in this short period of time? Firstly, when an earthquake occurs, balconies, elevator lobbies, and windows are extremely dangerous and must be kept away! If you are indoors, you should evacuate the building as soon as possible and rush to an open outdoor area. If the floor is too high or time is too tight to leave the room, be sure to pick up a cushion or pillow to protect your head, bend down to lower your center of gravity, hide in a small room with load-bearing walls, and firmly grasp solid objects to prevent shaking. Wait until the tremor is over before quickly escaping outdoors. If you are outdoors, it is not foolproof. At this time, you should observe the surrounding environment, stay away from tall buildings such as buildings, overpasses, and billboards. At the same time, you should also be careful of high-voltage lines, power poles, and other equipment, and choose nearby open areas to avoid danger.