Because the level of earthquake prediction, especially the level of imminent earthquake prediction, is not high enough, we should also pay attention to some macroscopic abnormal changes before the earthquake comes. Historical facts and scientific research have proved that some precursor changes may occur before earthquakes. Earthquake precursors refer to all kinds of signs related to the preparation and occurrence of earthquakes in nature before earthquakes occur. Generally speaking, there are two types: macro precursors and micro precursors. Those earthquake precursors that can be directly detected by human sensory devices are collectively referred to as macroscopic precursors, including: macroscopic anomalies of groundwater, animal anomalies, meteorological anomalies, ground sound and ground light. It is worth noting that the changes in nature are very complicated, and there are many reasons for various abnormal phenomena, not all of which are earthquake precursors.

Early warning phenomenon and time:

Judging from the feelings of people in Tangshan and other earthquake areas, there is generally about ten seconds' warning time from the earthquake to the destruction of houses. The early warning phenomena of major earthquakes mainly include: ground motion, ground sound, ground light, building shaking and so on.

Groundwater:

When the rock stratum is deformed, the state of the underground aquifer will also change, so the groundwater will often produce some abnormal phenomena: well water is bubbling in full bloom, rising and falling suddenly, turbid without rain, discoloring and stinking. However, groundwater is easily affected by the environment. So don't panic if you find anything unusual, report it to the earthquake department first.

The weather is dry, the well is flooded, and there are abnormal ups and downs.

Without rain, it becomes muddy, discolored and stinks.

The jet plane rang again and the flowers were in bloom.

Animal abnormality:

Many earthquake examples show that animals often behave abnormally before earthquakes. The following is a ballad about animal precursors before the earthquake:

Animals have precursors before earthquakes and report any anomalies.

Cattle, horses, mules and sheep don't enter the circle, and pigs don't eat dogs and bite people.

Ducks don't go into the water and make noise on the shore, but chickens fly up the tree and scream loudly.

The snake got out of the hole in the ice and snow, and the mouse moved away stupidly.

The rabbit jumped and bumped, and the fish jumped in panic.

Bees move noisily, but pigeons fly back to their nests in fear.

The voice of the earth is strong and strange.

The ground lamp is horribly bright.

Ground sound and ground lighting:

Before or during the impending earthquake, ground sound and ground light often appear together. The sound of the earth is similar to the roar of machines, thunder, guns and the roar of strong winds. Ground light has various colors and shapes, such as strip, sheet, sphere, column and fire light.