Why was the weather dry before the earthquake?

my country's earthquake scientist Geng Qingguo was the first to hear farmers say that a severe drought would be followed by a major earthquake, so he researched historical data and further increased the credibility of this judgment with more data. He investigated from 231 BC (the 16th year of the First Emperor of Qin) to 1971 AD (Table 1). During this 2,202 years, 69 major earthquakes with a magnitude of 6.0 or above occurred in North China and the Bohai region. Among them, the earthquake There were 27 droughts, 15 severe droughts two years before the earthquake, 16 severe droughts three years before the earthquake, and 9 severe droughts three and a half years before the earthquake. In summary, severe droughts occurred one to three and a half years before the earthquake. There were 67 droughts, accounting for 97.1% of the total number of earthquakes. And he also pointed out that the later an earthquake occurs after a severe drought, the higher the intensity of the earthquake. The larger the drought area, the greater the earthquake intensity.

As for the relationship between drought and earthquake, at first glance, the relationship between wind, horse and cow is irrelevant, just like the rooster's crow and the sunrise. However, philosophy tells us that the world is interconnected and connections are universal. Although we still do not know the inevitable link between drought and earthquakes, these empirical data make us convinced that there is an inevitable link between them.

We can also make some scientific guesses about this. We know that the temperature of air increases when it is compressed. When doing mechanical tests, we also found that metal or other objects will generate heat after being squeezed. On this point, we can also go to the factory of extruded aluminum profiles and ask the engineers, and it will become clear immediately.

Modern science generally believes that the various plates of the earth squeeze and rub against each other, thus giving birth to earthquakes. Due to the extrusion and friction of crustal rocks, the local temperature of the earth will also increase. This heat is conducted to the earth's surface, causing the surface temperature to rise. The surface heats the air, forming a large-area rising dry hot airflow. This rising dry hot airflow Nature is not conducive to the formation of rainfall, so the drought before the earthquake occurred. Rising thermals generally appear as low air pressure - there seems to be data to verify this.

From this, we can further derive a conjecture: a few years before the earthquake, the surface of the earth continued to release heat energy, and the heat energy released increased significantly compared with history. This area seems to be a red-hot hot stone with a large amount of rising thermal air currents, which is of course not conducive to the formation of rainfall.

The above is just a speculation. If this conjecture is true, we will further verify the following facts.

1. A few years before the earthquake, the temperature at a certain depth underground (such as 10 meters) will increase significantly;

2. The temperature difference at different depths underground will increase ( For example, the temperature difference between 10 meters deep and 20 meters deep will increase);

If the above two inferences are verified, the credibility of the drought-earthquake theory can be further increased.

As an extremely strong natural phenomenon, earthquakes must have countless signs before the earthquake. Take animals for example. Various animals differ greatly in certain functions, and their ability to sense earthquake precursors also varies greatly. Some animals are more sensitive to infrasound and ultrasonic waves than humans; some animals are more sensitive to small vibrations than humans; some animals are more sensitive to thermal changes than humans. If we actively collect this information, summarize experiences, and take precautions, we will surely realize our desire to reduce the extent of disasters.

Just as it is not accurate to judge the sunrise by the crowing of roosters, it is not accurate enough to judge earthquakes by drought. However, at this stage, this is still an empirical (empirical) method worthy of attention, and drought is a worthy Information that attracts attention.