Why earthquake warning can beat the earthquake wave

"Ten, Nine, Eight, Seven, Six, Five, Four, Three, Two, One." At 22:55 on June 17, the Sichuan Metropolitan High-tech Zone¡¯s big horn sent a huge 10-hour countdown and issued an alarm.

This is not a satellite launch, but an earthquake warning.

Later, according to the China Seismological Network, a magnitude 6.0 earthquake occurred in Changning County, Yibin City, Sichuan Province, with a focal depth of 16 kilometers, followed by multiple aftershocks. According to the official Weibo news from the Emergency Management Department, as of 8:30 on June 18, the earthquake has caused 12 deaths and 125 injuries. The rescue is currently underway.

According to the news released by the official micro-distribution of Chengdu High-tech Disaster Reduction Institute, Chengdu received an early warning 61 seconds ahead of the earthquake. 180 schools and 110 communities in Chengdu received early warnings and were evacuated.

A staff member of the Chengdu High-tech Disaster Reduction Institute told the interface journalist that, unlike earthquake prediction, earthquake warning is based on the principle that the wave is faster than the earthquake wave after the earthquake, and the electric wave is used to alert the epicenter to achieve the shock wave before the arrival. Early warning from a few seconds to tens of seconds.

How much help can early warning technology provide for ordinary people in response to sudden earthquakes?

Wang Dun, director of the Chengdu High-tech Disaster Reduction Research Institute, said at a press conference on June 18th, ¡°The Question Cloud Forum¡±: Research shows that the warning time is 3 seconds, which can reduce casualties by 14% and the warning time is 10 seconds. Casualties were 39%. In the Wenchuan earthquake, if there is an early warning, give Yingxiu a 10 second warning time, Beichuan 31 seconds warning time, Qingchuan 55 seconds warning time, can reduce the death of 2-3 million people, which can reduce 30% of deaths.

The above-mentioned staff of the Chengdu High-tech Disaster Reduction Institute presented the road map of the earthquake warning technology to the interface journalists.

To do a good job in earthquake warning, we must first construct a high-density seismic early warning sensor network in the main seismic zone; monitoring information is collected and collected by sensors for timely analysis and processing, and then through various means such as mobile phones and televisions, etc. And provide earthquake warning services to the public.

The person said that the sensor as the front-end monitoring device is the first link of earthquake warning. The general sensor is installed in a place where the power supply is stable. If the power is temporarily turned off, the backup battery will be activated, which can support more than ten hours. ¡°Generally, before the local power grid is cut off, earthquake warning information has been sent out,¡± he said.

After the sensor collects the data and sends an earthquake warning, the average time is 6 seconds, which beats the seismic wave transmitted 3.5 kilometers per second.

The person said that the earthquake system early warning software was independently developed by Chengdu High-tech Disaster Reduction Institute and deployed locally on a third-party private cloud to analyze the data and issue an early warning through artificial intelligence algorithms.

Chengdu High-tech Disaster Reduction Institute was founded in 2008. It has joined forces with the National Seismological Bureau of China, and has established a continental earthquake early warning and emergency network covering an area of 2.2 million square kilometers, covering 90% of the population of the China earthquake zone, with about 660 million people, successfully warning Lushan 7 52 devastating earthquakes including the earthquake, the Jiuzhaigou 7 earthquake and the Changning 6.0 earthquake.

The staff also introduced that the Chengdu High-tech Disaster Reduction Institute is equipped with a UPS battery system (usually a lead-acid battery), and another equipment center, even if the Chengdu High-tech Zone is powered off, the local operation cannot be performed, and it can automatically switch to other centers without affecting. The entire warning service.

Now, the most important problem to be solved is the ¡°last mile¡± of the public for earthquake warning services.

The source said that the current 13 earthquake zones (prefectures and cities) in Sichuan Province have opened the service of TV seismographs, and 60 communities in Chengdu High-tech Zone have launched the earthquake warning "big horn", which is obviously not enough, calling for more cities on the earthquake zone. The state has opened television and mobile seismograph services, especially for schools and communities.

In response to the "last mile" of the earthquake warning, some netizens in the earthquake zone said that they received the aftershock warning from the "earthquake warning" APP of Chengdu High-tech Disaster Reduction Institute. Some netizens also said on Weibo that the Android application has a flashback and stays on the registration page. Apple users strongly recommend updating the mobile app. The iOS version is still in 2015, and the new version cannot be adapted.

In this regard, another staff member of the Chengdu High-tech Disaster Reduction Institute told the interface journalist that the Android phone also needs users to set up. The Apple mobile APP version does need to be updated. There are too many things to do and there are not enough people, but it will step up maintenance and upgrade. .

It is completely different from the earthquake warning after the earthquake. The earthquake prediction is still a global problem.

Wang Dun said that in May 2018, Sichuan and Yunnan, which are in the earthquake zone, have begun to build China's first underground cloud map network. It plans to build 2000 underground cloud map monitoring stations in Sichuan and Yunnan, and the data will be transmitted to the forecast center in real time. Real-time processing, generating underground cloud maps, similar to the ¡°seeing pictures¡± of weather forecasting, automatic or manual analysis, research and analysis of underground cloud maps, and prediction of earthquakes.

The underground cloud map network enables dynamic monitoring of 8-20 km of stress and energy in the ground by installing sensors on the surface. ¡°Under the underground cloud map network for three years, it can have more than 10 underground cloud map data of the magnitude 5 earthquake. Summarizing these cloud map data will inspire earthquake prediction.¡± Wang Dun said.

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