Is it related to drought?4 Ask to answer the earthquake

Text ｜ "China Science News" reporter Feng Lifei

At 12:52 on September 5, a magnitude 6.8 earthquake occurred near Luding County, Ganzi Prefecture, Sichuan, with a depth of 16 kilometers. As of 14:00 on September 7, the earthquake had killed 74 people and 35 people lost contact. At present, the Office of the State Council's Earthquake Resistance Headquarters and Emergency Management Department have raised the national earthquake emergency response level to the second level, and the work of earthquake relief is under intense development.

What is the difference between this earthquake and the geological background of the Wenchuan earthquake 14 years ago? How is the aftershock? Is there an abnormal climate that is related to the netizens? What have been improved in my country's earthquake early warning for more than ten years? "China Science News" interviewed relevant experts.

One question: What is the same as the geological background of the Wenchuan earthquake?

"This Luding earthquake, the broken belt and earthquake movement are different from the Wenchuan earthquake 14 years ago." Xu Xiwei, the dean of the National Institute of Natural Disaster Prevention and Control, told the Journal of China Science.

The Luding earthquake is near the west of the south section of the freshwater river, and it belongs to a slippery earthquake. The Wenchuan earthquake is in a broken belt in Longmen Mountain, which is a reverse earthquake. "For example, after the Wenchuan earthquake collided with two cars, one car flew to another roof in the front of a car; and the Luding earthquake was equivalent to two cars passing by, and the distance changed. The distance changed. But there is no change in the high journey. "Xu Xiwei said.

Xu Xiwei said that the fresh water rivers are in the mountain canyon. The Gongga Mountain on the west is the highest place in the east margin of the Qinghai -Tibet Plateau, with an altitude of more than 7,500 meters. "In addition to the damage caused by earthquake vibration, it is easy to trigger secondary geological disasters such as slippery slopes, collapse, and mudslides during the earthquake, leading to house damage and personnel damage." He said.

Wang Yan, director of the Chengdu High -tech Disaster Specification Institute, said that there are three main fracture bands in Sichuan Province, namely Songpan -Longmen Mountain Fracture Belt, Fresh Water River Fracture Belt, and Anning River -Corimu River Fracture Belt. The Luding earthquake is located near the three major fracture bands near the intersection point.

Despite the different breakders, Wang Yan said that the Luding earthquake occurred like the 2008 Wenchuan earthquake, which occurred on a larger north -south earthquake zone.

This earthquake belt was caused by the collision between the Indian sector and the Asia -Europe sector. It can be extended north to Mongolia and south to India. It passes through Ningxia, Gansu, Sichuan, and Yunnan in my country. Grand earthquake. In recent years, 6 or more earthquakes such as the Ludian earthquake, Jinggu earthquake, and Jiuzhaigou earthquake in Sichuan have occurred here.

Two questions: How is the aftershocks?

Can this Luding earthquake still cause a stronger aftershock? Wang Yan believes that this possibility exists. At present, the surface rupture of the Luding earthquake is about 30 kilometers, and the territorial stress energy more than 30 kilometers away has changed very little, and a magnitude 7 earthquake may still occur. "This earthquake released some energy, and some energy needs to be released," he said.

Xu Xiwei also said that the China Earthquake Administration has always believed that there are risks of magnitude 7 or above here. He was worried that this earthquake may be the front earthquake of a larger earthquake, which will trigger the main rupture of the main body of the Anning River Fracture Belt and the Daliangshan Fracture Belt in the south, and more research is needed.

The China Earthquake Network is investigating the local aftershocks. According to the latest news, as of 7 o'clock on September 7, a total of 13 aftershocks were recorded at level 3.0 and above, of which 4.0 ~ 4.9 earthquakes were 2 times, and magnitude 3.0 ~ 3.9 earthquakes were 11 times.

Three questions: Is there a relationship with abnormal climate?

On September 6, in order to assist in the reconstruction of post -disaster recovery, Sichuan Province terminated the fourth -level drought resistance response due to the continued high temperature and drought on July 15. In this regard, some views that support the "drought earthquake theory" believe that drought may be a precursor to the great earthquake -friction of the pre -stratigraphy before the occurrence of the earthquake will lead to fever, which will cause the surface temperature to rise and drought.

Wang Yan believes that his scientific evidence is insufficient. "The disassexation of the great earthquake occurred around 10 kilometers underground. Even if the heat there was transmitted to the surface, it would take a hundred years, thousands of years, or longer. The drought cannot be associated with the large earthquake within a few years." Before the earthquake, there was no drought in the entire province of Sichuan.

In addition, after the earthquake, the China Meteorological Administration released the weather forecast saying that in the next 3 days, Luding County had more rainfall weather. Some netizens said that after the earthquake in Tangshan and Wenchuan, weight disasters such as heavy rains or hail were occurred.

Is this kind of weather abnormalities related to the exposure of chemicals released by underground rocks after the earthquake, causing atmospheric disturbance?

Wang Yan said that "accidental phenomenon" cannot be regarded as "false association". "For example, the Lushan Earthquake did not cause rupture on the surface, and the underground gas and chemicals could not be released, but it was also raining because it was facing the rainy season at the time." He suggested that scientifically guided online public opinion to carry out earthquake -proof disaster reduction work normally.

However, Xu Xiwei said that whether the occurrence of heavy rain after the earthquake is related to the changes in local climate conditions caused by the earthquake, related research must be carried out, such as some landmaking tracking and monitoring. Because this composite disaster plus the second disaster will increase the degree of disasters, it is necessary to prevent meteorological disasters from the occurrence of meteorological disasters as much as possible.

Fourth question: What is the progress of my country's earthquake early warning forecast?

In the face of worldwide problems with earthquake forecasting, Xu Xiwei admitted that in the past ten years, through big data combined with artificial intelligence technology, earthquake forecasting is transforming from experience forecast to physical forecasting of models and theoretical guidance. However, this aspect is still in the preliminary exploration stage, and the level of earthquake monitoring and forecasting has not yet been expected to make great progress. "Like this Luding earthquake, we have pushed forward the fracture band activity, but due to the lack of in -depth understanding of the earthquake mechanism and the process of occurrence, the earthquake forecast still has challenges." He said that in the future A large leap.

In order to prevent it before, Xu Xiwei said that a necessary basic work is to draw a national activity fault distribution map through a large scale to fill out the picture, "dig out" the sources of earthquake disasters of the city, and strive to "avoid" urban development. He said that only about 160 activity fracture bands have been drawn out of the picture, and more than 1,000 activity fracture bands are existing in the country, and there is still a long way to go in this regard.

"Earthquake faults can be mixed with rocks in the depths of the underground earthquake. The houses on the surface of the fault are not as easy to tear a piece of paper." Xu Xiwei said that the current earthquake anti -seismic measures cannot stop this misalignment damage. Sex, so try to avoid the source of disaster.

In terms of earthquake early warning, many scientific teams tried to establish a "scientific test site for earthquake forecasting" in the Chuan and Yunnan region where the earthquake. Wang Yan said that since 2008, related technologies in my country have changed from scratch, from rushing to the leading world; in the United Nations initiated from the United Nations, from a single disaster to a disaster warning or even a disaster chain, my country's implementation efforts Global leading, earthquake early warning and road traffic emergency linkage channels are abundant; in the future, it still needs to continue to improve and improve existing emergency management mechanisms and measures.

"China Science News" (2022-09-08 The 1st edition of the news)

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