In movies, there is usually a heavy rain shortly after an earthquake. Many people think that this is a movie effect, in order to represent a disaster. But in fact, this is also the case in reality. There are many cases of rain after the earthquake and in history. So the question is, what is the relationship between earthquakes and rain?
rain
Before answering the relationship between earthquakes and rain, you need to briefly understand how rain is formed.
We know that liquid water on Earth evaporates into water molecules that float into the atmosphere. Since water molecules are composed of one oxygen atom and two hydrogen atoms, and the earth's atmosphere is mainly composed of nitrogen and oxygen , water molecules are lighter relative to the atmosphere.
According to Avogadro's Law: At the same temperature and pressure, any gas of the same volume contains the same number of molecules. Because this law has four "same" characters, it is also known as the law of four sameness .
If there are many water molecules in the air of an area, because water molecules are lighter than nitrogen and oxygen, the water molecules will slowly rise like a balloon.
In the process of rising, the earth's temperature and pressure are also constantly changing, and the "balloon" that wraps the water molecules will continue to expand under the changes of pressure and temperature. When it reaches a certain height, the air at this time will not be able to wrap more water molecules, so the water molecules will be precipitated.
However, water molecules hardly stick together, and even if they are touched occasionally, they will spread out quickly. Fortunately, the atmosphere is not pure and flawless, but there are many dust particles, etc. These dust particles will act as condensation nuclei, and water molecules will condense around the dust particles to form small ice crystals and small water droplets.
However, these small ice crystals and small water droplets are very small, so they are not rain, but clouds.
If there are more water molecules in this area, it means that the condensation nucleus will condense more water molecules, and raindrops or snowflakes will be formed at this time, which will fall on the ground. This is the formation mechanism of rain and snow.
The reason why rain formed after the earthquake was actually because the earthquake caused the increase of condensation nuclei in the air and the increase of water molecules in this area.
Earthquake rain
The occurrence of earthquakes is related to plate movement . We know that the inside of the earth is not a cold solid, but a hot one. Because the temperature of the earth's core exceeds 5000 degrees Celsius, it bakes the entire mantle layer melted, making the substance here molten.
When the high temperature mantle layer meets the icy rock layer, the phenomenon of thermal convection occurs, which causes the movement of the earth's plates. Earthquakes are usually also associated with plate movement.
When the plate moves, it will cause a lot of energy to accumulate between the plate and the plate. When the force is excessively accumulated, the crust will rupture and an earthquake will occur.
During the earthquake, the huge energy accumulated in the earth's crust will be released into the air, making the ground temperature rise, and the higher temperature will make the water evaporate faster.
The water vapor under the ground will also enter the atmosphere along the cracks of the earthquake, resulting in an increase in the moisture in the air and the formation of clouds, and the water content of the clouds will also increase.
On the other hand, the moment an earthquake occurs, it will destroy local buildings or damage the local landscape, causing dust on the ground to fly into the sky. These dust particles act as condensation nuclei, condensing moisture in the air together to form small water droplets or even small raindrops.
So, usually the earthquake is followed by rain.However, not all earthquakes will rain after the earthquake, which also depends on the magnitude of the earthquake, and various factors such as the temperature and latitude here. For example: earthquakes that generally occur in desert areas rarely rain.
In fact, not only earthquakes will cause rain , but forest fires will also cause rainfall, and the longer the forest fires last, the greater the rainfall.
This is because when a forest fire occurs, the higher temperature will cause the moisture in the soil and vegetation to evaporate; and the dust from the burning of the fire will enter the atmosphere and act as condensation nuclei, leading to the occurrence of rainfall. For example: After the violent forest fires in Australia in the second half of last year, there was another major flood.
Summary
We often say that there is a major epidemic after a major disaster, but in fact, it is because there is usually rainfall after an earthquake. This is because when the scientific level in ancient times was low, human beings could not predict the occurrence of earthquakes in advance, and there were no advanced rescue teams and rescue forces. As a result, a large number of people would die every time a major earthquake occurred.
After a large number of people die, if it is too late to bury, it will lead to the flood of local microorganisms. When the rain after the earthquake washes away the remains, the microorganisms on the remains will be mixed into the groundwater or drinking water, making the surviving people sick.
In addition, dammed lakes are easily formed after an earthquake. If there is too much rainfall after an earthquake, it is likely to cause the dammed lake to collapse, posing a threat to the downstream.
According to these phenomena, experienced rescue teams will sort out these potential threats in a timely manner during rescue, so as not to cause secondary disasters.
