Why are there signs before an earthquake occurs?

This question is very representative and will make many people confused. I also want to systematically express my views.

First of all, let me emphasize that the law of cause and effect determines that there must be a cause if there is an effect. An earthquake is a huge release of energy in the earth's crust, and it's not surprising that there are some obvious signals before an earthquake occurs. But there are significant differences between what science calls signs and what people generally think of as signs.

In most people’s minds, before an earthquake occurs, there will often be some abnormal natural phenomena such as rivers drying up inexplicably and wells boiling; or some inexplicable phenomena such as rats taking to the streets or cats and dogs becoming manic. animal anomalies. However, these phenomena are not absolute standards for judging whether an earthquake has occurred, and the two cannot be simply equated. Although in history, similar abnormal phenomena did occur before many earthquakes occurred, because the causes of these phenomena are very complex and difficult to accurately characterize and quantify, it can only be regarded as an empirical statement and cannot be Raised to a scientific theory, it cannot be used as a criterion for judging whether an earthquake has occurred. To scientifically predict earthquakes, we must start with research on the causes of earthquakes.

Here is a real case: In 2009, residents of L'Aquila, Italy, felt some slight shaking, and rumors about earthquakes spread like wildfire in the local area. The Italian government formed a seismic assessment team consisting of six scientists and one government official to investigate the incident. After detailed investigations, these seven scientists believed that the possibility of an earthquake in the area was very low, but they still recommended that local buildings be reinforced for insurance purposes. But unfortunately, the earthquake really happened and caused a large number of casualties, so the six scientists and the government official were brought to court for manslaughter. The incident caused an uproar around the world, especially among scientists. Because from a scientific point of view, it is very difficult to predict earthquakes, and it is almost impossible to do it with human science and technology at this stage. In the end, the six scientists and the official were acquitted following protests from the scientist group.

It is a vibration caused by the rapid release of energy in the earth's crust. It is usually caused by the mutual extrusion and collision of rock plates in the earth's crust, causing dislocation and rupture at the edge of the plate and within the plate. This is The main cause of earthquakes is what we usually think of as earthquakes. In addition, large-scale volcanic eruptions and large-scale energy explosions on the surface or underground can also cause earthquakes. For example, modern nuclear tests and asteroid impacts can also cause earthquakes.

How did the earthquake happen? The usual theory is that the earth is divided into three layers, the central layer is the flowable core; the middle layer is the mantle, and the outermost layer is the rocky crust, which is about 35 kilometers thick. Due to the discontinuity in the distribution of the earth's crust, six relatively large plates are formed on the earth. The plates squeeze and collide with each other to form earthquakes. Because the crustal structure is too large, complex, and not intuitive, it is difficult to accurately monitor its movement, and it is difficult to predict earthquakes.

From a broader perspective, the occurrence of earthquakes often has more complex causes. The deepest earthquake source known in modern times is 720 kilometers, which is difficult to explain by simple plate movement. It has some microsecond connection with the changes in the earth's internal mass, the balance of gravity between celestial bodies, and the abnormal flow of the earth's core. Therefore, it is precisely because earthquakes have so many complex causes, and so many uncontrollable factors, that it is technically almost impossible to accurately predict earthquakes in modern times.

It is precisely because of this that when the Italian court initially declared the scientists and officials responsible for investigating the L'Aquila earthquake guilty, it caused a fierce backlash from scientists around the world. Due to the huge destructive power of earthquakes, governments in various countries are very cautious about earthquakes in order to avoid unnecessary panic.

As mentioned above, due to the complexity of earthquake causes and the existence of many unpredictable factors, it is difficult to accurately predict earthquakes scientifically at this stage.

Therefore, people's accumulated experience with earthquakes is often based on statistics.

For example, before many earthquakes in history, extreme anomalies in animals occurred. For example, domestic animals such as cats and dogs are extremely manic. This is because regular earthquakes often require a time for energy to accumulate. The animals' sense organs are more sensitive than humans, so they can predict this risk in advance. However, since this phenomenon is not unique, not only earthquakes can cause animals to become manic, nor can animals sense every earthquake in advance, so it is difficult to conduct accurate data analysis, so usually these experiences It can only be used as a reference for seismologists. There is no need to panic when seeing such a phenomenon. Although scientists cannot accurately predict earthquakes at this stage, they will still give you a reasonable suggestion.

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Unreliable! Unfortunately, human beings are not yet able to predict earthquakes accurately to hours, days or even years, only the probability of occurrence. Many of the so-called signs were made up by people through their own memories after the earthquake. For example, rats swarmed out of the surface in large numbers, toads moved away, puppies went crazy, there were strange clouds in the sky, the pond water heated up, the water smelled of sulfur, etc.

The interior of the earth is a hot, A viscous mushy sphere, the rocks are all in a molten state, and the temperature is at least between 2000-6000 degrees Celsius. The surface is just a thin layer of cooled shell. The internal high temperature and high pressure state makes this shell quite unstable. Magma Like a trapped beast, it always wants to come out and wreak havoc. In fact, the pressure inside the earth needs to be released, and the thin shell cannot withstand it and breaks. The Mariana Trench is deep enough, 11,000 meters, and Mount Everest is high enough, 8,848 meters. The sum of the two is less than 20,000 meters, but the radius of the earth is 6,371,000 meters! According to the proportion, the thickness of the earth's crust is not as thick as an egg shell, and what is wrapped inside is thousands of degrees of magma, not egg white.

Big movements like earthquakes are highly disastrous, but humans have not yet found a good way to predict them. Earthquake clouds, earthquake lights, etc. are not very reliable. There may be early warnings for changes in the geomagnetic field or certain electric fields, but humankind's current detection technology is not yet able to capture such weak signals.

Life on earth was born about 500 million years after the formation of the earth. For more than 3.8 billion years now, life has been fighting various natural disasters. Of course, earthquakes are one of the most frequent types of resistance. Therefore, the genes of many organisms have been implanted with risk-avoidance fragments, that is, instincts. Many animals have hearing or smell that are far beyond that of humans. For example, dogs can hear To ultrasonic waves, elephants can feel infrasound waves, and mice can smell sulfur. These are beyond the reach of human senses. After hundreds of millions of years of development, their instincts tell them to avoid danger.

Human beings have no choice but to realize it later, because human beings have only lived under the roof for tens of thousands of years. In the early days, they were still jumping among the trees. When we When our ancestors were still primitive people, they were running and sleeping on the grasslands. When an earthquake came, there was no need to panic, because there was nothing that could hit us. Later, when we lived in big houses, trouble came. Our instincts do not have this Modern technology cannot capture the advance due to this hedging mechanism, so it will suffer huge losses and even cost lives.

In a country with many earthquakes like Japan, where earthquakes occur several times a day on average, I heard that a few people have this premonition. During the Great Hanshin Earthquake, thousands The person ran out 30 seconds early, and even they themselves were surprised afterwards. For this reason, they also underwent a lot of brain wave tests, but there was nothing weird about it, and nothing happened in the end.

Otherwise, if we live in space, we can avoid earthquakes, but meteor impacts are unavoidable. Everything is a matter of probability. Learning some knowledge about earthquake prevention and disaster relief may be able to save ourselves. One life, instead of being suspicious all day long, observing small animals or clouds. The chance of being killed by an earthquake is definitely smaller than the chance of being hit by a car, so just go to sleep!

It is caused by the strength of the magnetic field in the air, just like "strong convection"

My insomnia means there is trouble in the world.