China News Agency, Chengdu, February 9th: Has the world entered a new round of major earthquakes?
——Exclusive interview with Xu Qiang, vice president of Chengdu University of Technology and deputy director of Chengli Earthquake National Laboratory
China News Agency reporter He Shaoqing
At 9:17 and 18:24 on February 6, Beijing time, two 7.8-magnitude earthquakes with focal depths of 20 kilometers occurred in Turkey.
According to Agence France-Presse, on February 8 local time, the earthquake that struck Turkey and northern Syria on the 6th has killed more than 15,000 people.
After the Turkish earthquake, the State Key Laboratory of Geological Hazard Prevention and Geoenvironmental Protection of Chengdu University of Technology (referred to as "Chengli National Key Laboratory of Geological Disasters") predicted the landslides induced by the Turkish earthquake swarm, and immediately sent relevant data to Shared with Turkish counterparts.
Why was the earthquake in Turkey so destructive?
Has the world entered a new round of major earthquakes?
How should human beings uphold the concept of a community with a shared future for mankind and deal with possible natural disasters?
Xu Qiang, vice president of Chengdu University of Technology and deputy director of the Chengli Earthquake National Laboratory, accepted an exclusive interview with China News Agency's "East and West Questions" to explain this.
The interview transcript is summarized as follows:
China News Agency reporter: Why is the earthquake in Turkey so destructive?
Xu Qiang:
The earthquake in Turkey was very destructive. In addition to the high magnitude of the earthquake itself, there were multiple factors such as the superimposition of two strong earthquakes, the proximity of the epicenter to the city, the lack of earthquake resistance of buildings, the time when the strong earthquake occurred, and the climate.
In the past strong earthquake rescue sites, people often saw that some mountains and buildings were crumbling, but they did not collapse as a whole. However, if the earthquake time was extended by more than ten seconds, there may be completely different results.
In Turkey, two 7.8-magnitude earthquakes occurred within a short period of time. Many buildings and mountains that were shattered for the first time were seriously damaged in the second strong earthquake.
The first strong earthquake in Turkey occurred at around 4:00 a.m. local time. Many people were asleep and had no time to save themselves and escape.
At the same time, the severe cold climate shortens the outdoor survival time of human beings, which is not conducive to post-earthquake rescue.
The picture shows local time on February 9, an aerial photo of the disaster-stricken area in Kahramanmaras, Turkey.
China News Agency reporter: Compared with common earthquakes, what are the new features of this earthquake? What challenges does this pose to post-earthquake rescue?
Xu Qiang:
Different from common main and aftershock earthquakes, the Turkish earthquake is a double-shock earthquake in the earthquake swarm type.
A double-shock earthquake refers to two earthquakes of similar magnitude occurring one after another within a short period of time.
Although double-shock earthquakes are relatively rare, double-shock earthquakes have occurred in the Eastern Anatolia fault zone where the Turkey earthquake is located.
The two earthquakes of the double-shock type earthquake generally occur on two faults that are close together and have a relationship. At present, there seems to be no case of two strong earthquakes occurring on the same fault in a short period of time. Generally, one fault experiences one strong earthquake. After the earthquake, it will be completely broken, and it will not break again in a short period of time.
Similarly, after a fault ruptured in Turkey, the stress of this fault was adjusted, which in turn affected nearby faults, and nearby or related faults also caused earthquakes due to stress adjustment.
Just like a group of people huddling together, if one person falls down, the person next to him may also fall down.
The East Anatolia fault zone is located at the junction of the Arabian plate and the African plate. This fault zone is relatively wide and consists of multiple secondary faults.
After a fracture ruptures, the stress of nearby fractures will be adjusted, resulting in stronger aftershocks.
At the same time, the superimposition of the two strong earthquakes paralyzed the traffic and made rescue more difficult.
China News Agency reporter: How long is the secondary disaster caused by the earthquake in Turkey expected to last?
Xu Qiang:
The secondary disasters caused by the earthquake are mainly landslides and mudslides caused by heavy rainfall.
After the Turkish earthquake, the Strong Earthquake Geological Hazard Research Team of Chengli National Geological Disaster Laboratory used the previously developed earthquake-induced landslide prediction model to predict landslides induced by the Turkish earthquake swarm.
Prediction results of Turkish earthquake swarm-induced landslides (left) and their spatial relationship with cities and populations (right).
Photo courtesy of Chengli National Key Laboratory of Earthquake Disasters
Prediction results show that the landslide-prone areas in Turkey are mainly distributed along the East Anatolia fault zone.
Aleppo, Gaziantep, and Antakya, where the population density is the most concentrated in the earthquake-stricken areas, are located at a certain distance from the main body of the mountain range, and are located in the medium-low prone area where the threat of landslide hazards is small.
However, due to the poor earthquake resistance of Turkish buildings, they still face the problem of house collapse and damage.
Several densely populated towns along one side of the mountain range are located in the medium-high susceptible zone.
There is a threat of landslides and collapses in the immediate vicinity of the mountain.
Kahramanmaras is located in the Eastern Anatolia Mountains, and the mountains on both sides are located in the middle-high risk-prone areas, facing the risk of landslide disasters. Attention should be paid to the impact of secondary disasters after the earthquake.
How long the secondary disaster will last is mainly related to the number, scale and severity of local co-seismic landslides.
Generally, secondary disasters directly caused by earthquakes will decay rapidly in about 10 years, but the attenuation does not mean that the secondary disasters will stop.
Fifty or sixty years after the Kanto Earthquake in Japan, the local geological disasters have not fully recovered to the pre-earthquake level.
Judging from the current remote sensing images, the secondary disasters caused by the Turkish earthquake are not too serious and the impact time is relatively short due to the terrain height difference and slope.
Xu Qiang looked at the experimental data at the National Key Laboratory of Earthquakes in Chengli.
Photo by China News Agency reporter An Yuan
China News Agency reporter: How did the Turkish earthquake affect other countries? Has the world entered a new round of major earthquakes?
Xu Qiang:
When the Turkey earthquake struck, many countries on the three continents of Asia, Europe and Africa felt the tremors. Neighboring Syria was the most affected, and some countries north of Turkey were also affected.
Every earthquake is a stress adjustment, which affects the whole body.
After a fracture breaks, it tends to affect the adjacent fracture stress for adjustment.
There have always been many strong earthquakes in the world in history, and it is not just that there are so many strong earthquakes today.
At present, it is not possible to judge whether the Turkish earthquake will lead to an increase in the number of global earthquakes, but it can be determined that after this earthquake, earthquakes on the East Anatolia fault zone where the Turkish earthquake is located will enter an active period, because the fault zone on this fault zone The stress will be adjusted gradually, and the adjustment range will gradually expand.
China News Agency reporter: In the face of disasters, how should we uphold the concept of a community with a shared future for mankind and respond together?
Xu Qiang:
After the earthquake in Turkey, the Chinese government immediately launched an emergency humanitarian assistance mechanism to provide emergency assistance to Turkey and Syria.
In the first batch, 40 million yuan of emergency aid was provided to Turkey, and 30 million yuan of emergency humanitarian aid was provided to Syria.
In addition to dispatching the Chinese rescue team to rush to the earthquake-stricken area in Turkey, various non-governmental rescue teams also set off one after another.
After predicting the landslides induced by the Turkish earthquake swarms, the Chengli National Geological and Disaster Laboratory shared the relevant data with Tolga Gorum, a Turkish earthquake expert at Istanbul University of Technology.
The picture shows that on February 9, local time, a woman was rescued by search and rescue personnel under the ruins of a collapsed building in Hatay, Turkey.
Image source: Visual China
When Tolga Gorum was studying for a Ph.D. in the Netherlands, he came to Sichuan to study at the suggestion of his supervisor. His doctoral thesis was to study the "5.12" Wenchuan Earthquake.
Next, Chengli Earthquake National Key Laboratory will cooperate with Tolga Gorum in research, hoping to provide more scientific and technological support for local earthquake rescue and post-disaster reconstruction, so that rescue forces can go to the most needed places as soon as possible.
When the "5.12" Wenchuan earthquake occurred, the international community extended a helping hand to China.
Similarly, after the 2010 Haiti earthquake, the 2011 Japan earthquake, the 2015 Nepal earthquake, and the 2018 Central Sulawesi earthquake in Indonesia, China also immediately provided humanitarian assistance, including the golden 72-hour Rescue, deliver disaster relief materials, provide scientific and technological support, and post-disaster reconstruction.
China has also released some geological disaster data to international scholars free of charge, sharing geological disaster monitoring and early warning technologies.
Next, Chengdu University of Technology also plans to communicate with countries along the “Belt and Road” to help countries with frequent landslides monitor and warn landslides, and share the “Chinese experience” of emergency response to major natural disasters.
It is very difficult for any country in the "global village" to deal with sudden major natural disasters by itself.
Similarly, the influence of the earth's environment is affected by the interaction of multiple circles. When natural disasters such as earthquakes, floods, and fires occur in a country, they will also have global impacts.
Only by adhering to the concept of a community with a shared future for mankind and working together can we better deal with extreme natural disasters in the "global village".
(over)
Respondent profile:
Xu Qiang, vice president of Chengdu University of Technology, deputy director of Chengli National Laboratory for Earthquake Disasters.
He has presided over more than 60 major projects and topics, participated in the emergency response to dozens of major geological disasters such as the Wenchuan Earthquake, Lushan Earthquake, and Jiuzhaigou Earthquake, and achieved a "new breakthrough" in landslide early warning in the world.