Can humans really understand the “temper” of the Earth?

On February 6, a strong earthquake with a magnitude of 7.8 struck southern Turkey, killing more than 36,000 people, making it the deadliest earthquake in the 100-year history of the Republic of Turkey. Another "aftershock" that has attracted attention is that buildings located on multiple earthquake fault lines collapsed "pancake-like" after the earthquake. For this reason, the Turkish Ministry of Justice has authorized nearly 150 local prosecutors' offices to set up "earthquake crime offices" to investigate contractors, architects, geologists, engineers and other personnel related to the collapse of shoddy buildings.

This reminds me of an "earthquake lawsuit" 13 years ago: the L'Aquila Public Prosecutor's Office in Italy filed a lawsuit against seismologists in the area, accusing them of murder, because before the L'Aquila earthquake that killed more than 300 people, these seismologists analyzed and discussed the small earthquakes that had occurred and concluded that there was no sign that a destructive earthquake was about to occur.

This matter was quite controversial at the time. A supervisor of the Italian National Geophysical Institute stood up to defend: No one can accurately predict earthquakes. If these seismologists really did it, it would be nonsense. Seismologists cannot make accurate predictions about whether there will be an earthquake. Some rough judgments, such as: the probability of an earthquake with a magnitude of 8.0 or even higher in the next 50 years is one in three. Such predictions are already the greatest contribution that seismologists can make at present.

Even funnier is that there were media reports that a few weeks before the earthquake (April 6, 2009), an Italian scientist had predicted a major earthquake near L'Aquila, but was reported to the police for "spreading panic" and was subsequently forced to remove his research data from the Internet.

Regarding these "earthquakes", I called a friend who used to work at the China Earthquake Administration to inquire. He told me that Turkey and Italy belong to the Eurasian seismic belt, and earthquakes of varying sizes have been occurring for a long time. Earthquake prediction is still a very complex scientific problem worldwide. How easy is it to make a successful prediction? The China Earthquake Administration has been committed to the scientific research of earthquake prediction. So far, it has only made a few recognized successful predictions, such as the 1975 Haicheng earthquake in Liaoning.

After the 2008 Wenchuan earthquake, I interviewed Chen Yuntai, a famous geophysicist and academician of the Chinese Academy of Sciences, and listened to him talk about the difficulties of earthquake prediction. In summary, there are three main points: the "impenetrability" of the earth's interior; the "infrequent" nature of large earthquakes; and the complexity of earthquake physics. The "impenetrability" of the earth's interior is a term used by the ancient Greeks. Now it means that humans are currently unable to go deep into the earth's interior, which is in a state of high temperature and high pressure, to set up stations and install observation instruments to directly observe the source of the earthquake. Even the depth reached by ultra-deep drilling is just "skin and hair", and this type of deep drilling is not carried out in the earthquake activity zone, so it cannot solve the problem of directly observing the source of the earthquake.

Scientists have been "arguing" for many years: Do earthquakes have clear patterns, rules or laws, or are they random, chaotic and unpredictable? In 1997, American geophysicist David Jackson published a pessimistic article in Science magazine: "Earthquakes are Unpredictable." Russian seismologist Galitzin is optimistic: "Each earthquake can be compared to a lamp, which burns for a short time but illuminates the interior of the earth, allowing us to observe what is happening there. Although the light of this lamp is still dim, there is no doubt that it will become brighter and brighter as time goes by, and will enable us to understand these complex phenomena in nature."

Although it is possible to say so, it is not so simple to do it. Because the distribution of earthquakes is not uniform, the global earthquakes mainly occur in the three seismic belts of the Pacific Rim, the Eurasian Seismic Belt and the Mid-Ocean Ridge Seismic Belt, and there are not "lights" everywhere. The "light" of earthquakes cannot illuminate every corner of the earth's interior. Moreover, the interior of the earth is very uneven and not very "transparent". Seismologists can't even "see flowers in the fog" when "seeing" the interior of the earth from the surface of the earth. All these have greatly limited human understanding of the environment where the source of the earthquake is located and the source itself.

On the back of the Mayan sun god Tonatiuh, there is a symbol representing an earthquake. According to the Mayan astronomical calculations, an earthquake will eventually destroy the current world and the sun. The ancient Greeks believed that earthquakes may be the movement of a kind of "air" underground. In ancient Greek mythology, the god who specifically controls earthquakes is called Seismos, which is how the word seismology in English comes from. Image source: provided by the author

Chen Yuntai believes that the question of whether earthquakes can be predicted, which is being studied by scientists, has profound scientific implications and cannot be simply attributed to "saying that earthquakes cannot be predicted is promoting agnosticism" and so on. In his opinion, since the difficulty of earthquake predictability stems from the fact that people cannot measure the state of faults and their surrounding areas with high precision, and that they still know almost nothing about the physical laws involved, then if these two aspects can be improved, it will be possible to predict earthquakes several years in advance in the future.

Although short-term earthquake prediction is a global problem, scientists have not given up exploring it. Zhang Ying, executive deputy director of the Emergency Science Popularization Professional Committee of the China Science Writers Association, who once worked at the Beijing Earthquake Administration, has been engaged in emergency science popularization work in recent years and has written many articles on emergency science popularization for the Science Popularization Times. He especially called for the promotion of earthquake early warning projects, so that people can live in more solid houses, and carry out emergency science popularization education. If everyone can understand safety and everyone can respond to emergencies, then at critical moments, they can effectively protect their own and others' lives.

Source: Popular Science Times

Author: Yin Chuanhong

Editor: Mao Mengnan

Review: Wang Fei

Final judge: Yin Chuanhong