Now that science is so developed, why didn't Wenchuan earthquake be predicted in advance and then residents were evacuated?

The current technology can do the following

1. After the earthquake, know it 30 seconds in advance and call the police before the destructive seismic wave arrives.

Obviously, even if every resident has an alarm device, he can only run down three floors in 30 seconds, which makes no sense.

The point is, if the alarm happens in the middle of the night, 30 seconds is not enough for you to understand what happened.

More importantly, even if everyone calls the police for nothing (in fact, it is a pager), who can call the police every day every year?

2. The prediction of an earthquake in a certain area is generally as follows: In XX area, the possibility of an earthquake of magnitude 7 or so in the next 50 years is higher than 50%.

Is this prediction useful to you? You will live in a tent for 50 years? Or is the XX area moving from now on, leaving no one behind?

This kind of prediction can only be used by the state, which requires that the seismic grade of buildings in XX area should be raised to above 7 in the future, and relevant departments should do drills and plans.

The prediction in Beijing area is that it is unlikely that an earthquake of magnitude 6 or above will occur in the next 50 years, and the probability of an earthquake of magnitude 5 or above is less than 20%. Therefore, the seismic grade of buildings designated by the Beijing regional government is generally 7.

As for the accurate prediction of the future 1 week, there are only 1 times in human history, China, Xingtai, 1976, which is still the result of many coincidences.

Wenchuan area is an earthquake-prone area, and the seismic grade should be 8. However, hey hey, policy designation is one thing. In the actual construction, the boss will play tricks, not to mention 1980- 1990 years of a large number of projects almost no drawings, there is no construction supervision (at that time, it would be good to have a building to live in).

The weather forecast is only 80% accurate, not to mention the earthquake.