Why was there no warning before the earthquake?

Earthquake prediction is the prediction of the time, place, magnitude and influence of destructive earthquakes in the future.

The three elements of earthquake prediction refer to the time, place and magnitude of an earthquake.

Earthquake prediction method

There are generally three methods for earthquake prediction: seismic geology method, seismic statistics method and earthquake precursor method, but the three methods must be combined and supplemented to achieve better results.

Types of earthquake prediction

Long-term prediction: earthquakes that may occur in ten to one hundred years;

Medium-term prediction: earthquakes that may occur in several months to several years;

Short-term forecast: earthquakes that may occur in a few days to several months;

Impending earthquake prediction: an earthquake that may occur within a few hours to a few days.

Earthquake prediction case

Predicting earthquakes is a long-term wish of people. However, because the earthquake happened underground, it can't be directly observed, and the influencing factors are very complicated, which has not been completely solved. There are both successful experiences and lessons of failure.

Some successful cases:

1February 4, 975 Haicheng, Liaoning, earthquake with magnitude 7.3;

1May 29, 976, Longling, Yunnan, earthquake with magnitude 7.5;

1August, 976 16 Songpan earthquake with magnitude 7.2 in Sichuan;

1976165438+1the Sichuan Yanyuan earthquake of magnitude 6.7 on October 7;

1July 995 12 Menglian, Yunnan, earthquake with M = 7.3.

Present situation of earthquake prediction

Earthquake prediction is a very complicated worldwide scientific problem, and it was only more than 30 years ago that mankind officially began to explore earthquake prediction. Now we know the principle and law of earthquake preparation, but we haven't fully understood it. We have been able to predict some types of earthquakes to a certain extent, but we can't make accurate predictions for all earthquakes; The medium and long-term forecast we have made has certain credibility, but the success rate of short-term and imminent forecast is still relatively low.

1In February, 975, the Haicheng earthquake of magnitude 7.3 in Liaoning Province was successfully predicted, saving thousands of lives. For the 1976 earthquake swarm of magnitude 7.2 between Songpan and Pingwu, the 1976 earthquake swarm of magnitude 6.7 between Yanyuan and Ninglang, and the 1998 earthquake swarm of magnitude 6.7 in Ninglang, I didn't predict 1976 Tangshan.

At present, including the United States, Japan and other developed countries, earthquake prediction is still in the exploratory stage, far less accurate than weather prediction.

Debate on earthquake prediction

In recent years, some scientists in the world hold negative opinions on earthquake prediction. Some people even published a paper on "the earthquake is unpredictable", which clearly put forward the argument that "the earthquake is unpredictable".

However, some seismologists have affirmed the achievements of earthquake prediction, and believe that the short-term prediction of earthquake location, time and magnitude will eventually be realized, while the long-term prediction is more prominent.