2021-10-06

What’s wrong with the false alarm of the early warning system of the Luzhou m S8.1 earthquake in Sichuan?

By yqqlm yqqlm

Yesterday (5th) evening, an earthquake warning information attracted attention. At 21:09:22 on October 5, 2021, a magnitude 8.1 earthquake occurred near Shangma Town, Naxi District, Luzhou City, Sichuan Province (28.52 degrees north latitude and 105.30 degrees east longitude), with a focal depth of 5km</ p>

What’s wrong with the false alarm of the early warning system of the Luzhou m S8.1 earthquake in Sichuan? </ P >

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p > when everyone was still in shock, at 21:51, the official microblog of China Seismological Network released a message saying: after verification, there was no earthquake with a magnitude of more than 3.0 in Luzhou, Sichuan</ p>

What’s wrong with the false alarm of the early warning system of the Luzhou m S8.1 earthquake in Sichuan?(1) </ P >

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p > subsequently, the Sichuan Seismological Bureau also apologized to the public on the official microblog for the false alarm of earthquake early warning: This is a false alarm of technical failure of the automatic processing system, and there was no earthquake above magnitude 3.0 in Luzhou, Sichuan. This is probably the most comforting apology. Netizens also expressed understanding and tolerance for this false alarm. So why is there a false alarm in the earthquake early warning system? Is it the same thing as earthquake prediction? How do earthquake early warning systems usually work? As soon as we get to know each other</ p>

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p > earthquake early warning occurs after an earthquake, which is different from earthquake prediction </ P >

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p > what is earthquake early warning? Earthquake early warning and earthquake prediction are not a thing. Earthquake early warning is the information that can quickly determine the parameters and impact of the earthquake by using the observation data recorded by the stations near the epicenter after the earthquake, and then send an early warning before the destructive seismic wave reaches a possible affected area. It should be emphasized that it happened after the earthquake</ p>

What’s wrong with the false alarm of the early warning system of the Luzhou m S8.1 earthquake in Sichuan?(2) </ P >

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p > earthquake prediction refers to the prediction of the magnitude, time and location of future earthquakes before the occurrence of earthquakes, and timely publication to the public. Earthquake prediction belongs to the category of “pre earthquake” disaster prevention, which is a worldwide problem, and the current scientific and technological level still needs to be continuously explored</ p>

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p > why is there false alarm in the earthquake early warning system</ p>

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p > why is there a false alarm in the earthquake early warning system? According to experts, when multiple seismic stations close to each other receive interference signals other than non seismic signals at the same time, it is easy to cause system false triggering, resulting in the release of false early warning information</ p>

What’s wrong with the false alarm of the early warning system of the Luzhou m S8.1 earthquake in Sichuan?(3) </ P >

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p > in addition to false positives, the earthquake early warning results may also be biased. For example, when making seismic parameter statistics for a small number of signals recorded at the initial stage, the incomplete use of signals will affect the determination of earthquake level. Finally, there are still some warning blind areas in earthquake early warning. Let’s listen to the introduction of experts</ p>

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p > experts: there is a certain early warning blind area in earthquake early warning </ P >

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p > experts said that there is a blind area in the earthquake early warning system. After the earthquake, it takes at least 3 to 5 seconds to process the information recorded by the seismic station closest to the epicenter, and then issue the early warning information, resulting in the failure of early warning within 20 to 30 kilometers of the epicenter, Precisely such an area is the area with the strongest ground movement, so earthquake early warning is basically ineffective for the most severely damaged polar earthquake area</ p>

What’s wrong with the false alarm of the early warning system of the Luzhou m S8.1 earthquake in Sichuan?(4) </ P >

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p > for earthquakes below magnitude 6, its damage area is mainly concentrated in the blind area, so its effect of disaster reduction is not very obvious</ p>

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p > according to experts, the effect of earthquake early warning is actually that the greater the magnitude, the more obvious the effect of disaster reduction</ p>

What’s wrong with the false alarm of the early warning system of the Luzhou m S8.1 earthquake in Sichuan?(5) </ P >

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p > Li Shanyou, director of the Institute of engineering mechanics of China Seismological Bureau, said: for the early warning time near the epicenter is very short, the more outward it is, the longer its early warning time will be, especially for large earthquakes, its potential damage area is very large, Even reaching the scale of hundreds of kilometers or hundreds of kilometers, our earthquake early warning efficiency will become more obvious, because the service area is wider and the audience is wider</ p>

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p > China Seismological Bureau: early warning can be received through early warning terminals, set-top boxes, mobile phones, etc. </ P >

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p > although the earthquake early warning system has certain limitations, it is already the best player in the world to compete with seismic waves. In fact, in order to better protect people’s life safety and national economic development, China is also trying to overcome this worldwide problem</ p>

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p > on July 27 this year, the China Seismological Bureau held a press conference and announced that the China earthquake early warning network has realized demonstration operation in Beijing, Tianjin, Hebei, Sichuan, Yunnan and Fujian</ p>

What’s wrong with the false alarm of the early warning system of the Luzhou m S8.1 earthquake in Sichuan?(6) </ P >

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p > users in these areas mainly obtain earthquake early warning information through early warning terminals, speakers, TV set-top boxes, mobile app, etc</ p>