Tangshan 5.1 Earthquake Department

  Experts believe that it is another normal ups and downs activity in the old earthquake area, and it is unlikely that an earthquake of magnitude 5 or more will occur in the old earthquake area in the short term.

  At 6:38 yesterday morning, a magnitude 5.1 earthquake occurred in Guye District, Tangshan City. According to the rapid assessment of earthquake damage and preliminary on-site investigation, the study concluded that the earthquake is unlikely to cause significant damage to buildings. Experts from the China Earthquake Networks Center believe that this earthquake is another normal ups and downs in the old earthquake zone of the Tangshan earthquake. According to the current observation data and analysis of earthquake examples, it is unlikely that an earthquake of magnitude 5 or more will occur again in the old earthquake area in a short period of time.

  The Beijing News reported that according to the China Seismological Network, a magnitude 5.1 earthquake occurred in Guye District, Tangshan, Hebei (39.78 degrees north latitude, 118.44 degrees east longitude) at 6:38 yesterday, with a focal depth of 10 kilometers. At 7:35, Tangshan Fire Official Weibo released news that rescue forces had reached the epicenter, no personnel were trapped and injured, and traffic roads were in good condition.

  According to the official website of the China Earthquake Administration, according to the rapid damage assessment and preliminary on-site investigation, the impact of the earthquake can reach six degrees, and the seismic fortification intensity of the earthquake area is eight degrees. .

  According to the statistics of Hebei Earthquake Administration, as of 10:00 yesterday, there were 33 aftershocks, 0 times above magnitude 4, 0 times of magnitude 3.0-3.9, 2 times of magnitude 2.0-2.9, 0 times of magnitude 1.0-1.9, 1.0 31 times below the level.

  The epicenter of the earthquake was located in Guye District, Tangshan City, 28 kilometers away from Tangshan City, 177 kilometers away from Beijing City, and 132 kilometers away from Tianjin City. The earthquake caused a strong quake in downtown Tangshan, Hebei. There are earthquakes in Langfang, Cangzhou, Hebei and other places.

  Some citizens in Beijing, Tianjin and other places said that they received earthquake warning information on TV and mobile phones, suggesting that the earthquake shear wave will arrive in a few seconds and the information such as magnitude and epicenter.

  Mr. Li, who lives near Jintai Road in Chaoyang District, told the Beijing News reporter that at 6:38:25, the mobile phone earthquake warning software suddenly popped up a message: an earthquake of magnitude 4.8 or so occurred near Guye, Hebei. The estimated intensity is 1.8 degrees, please avoid the risk reasonably! "I lived in a unit dormitory, and I didn't feel obvious shaking, and my colleagues around me didn't run out. Later, I saw a friend in the circle of friends send a message saying that it felt quite obvious." Mr. Li said.

  A citizen of Tianjin said on Weibo that an earthquake warning suddenly appeared on the TV screen in the morning, indicating that “an earthquake of magnitude 4.8 or so occurred near Guye, Hebei. Tianjin will feel a slight quake, please avoid the risk reasonably”, accompanied by the voice of a female broadcaster counting down . Then I felt shock.

  It is understood that the earthquake early warning software was developed by the Chengdu Institute of High-tech Disaster Mitigation. At 6:38, the official Weibo of the Chengdu Institute of High-Tech Disaster Mitigation released earthquake early warning information and gave Tianjin early warning 32 seconds in advance.

  Interpretation 1

  How does the earthquake affect Beijing?

  Will not have a significant impact on Beijing's crustal stress and strain and seismic activity

  Experts from the Beijing Seismological Bureau said that the earthquake caused a sensation in Beijing, among which Pinggu, Shunyi, Tongzhou and other regions in the east had a strong sensation. The maximum seismic intensity recorded by the instrument was III degrees, which occurred in Donggao Village, Machangying Town, Pinggu District, The town of Luoying Township and Longwantun Township of Shunyi District did not cause obvious earthquake damage and loss of human life and property.

  In fact, the seismic fortification intensity of Beijing is Ⅷ, which is much higher than the impact intensity of the earthquake on Beijing, so this earthquake will not affect Beijing's housing facilities.

  The epicenter of this earthquake is about 180 kilometers away from the center of Beijing. According to historical earthquake examples and physical model analysis, due to the long distance and small magnitude, this earthquake will not have a significant impact on Beijing's crustal stress and strain and seismic activity.

  Interpretation 2

  What is the relationship with the Tangshan earthquake?

  The undulating activity of earthquakes in the old earthquake area for a long time is normal

  Experts from the China Earthquake Networks Center believe that the 5.1 earthquake of Tangshan, Guye, Hebei Province occurred in the old earthquake zone of the Tangshan earthquake of 7.8 on July 28, 1976, which is the old earthquake zone of Tangshan earthquake following Tangshan on October 6, 1995. Another normal ups and downs activity after the Guye 5.0 earthquake.

  According to the China Earthquake Networks Center, the Tangshan M7.8 earthquake of 1976 had a large magnitude, and the quake activity in the aftershock area that lasted for a long time was normal. During the 7.8-magnitude earthquake on July 28, 1976 and the 6.2-magnitude earthquake on May 12, 1977, there were 27 earthquakes of magnitude 5 and above in the Tangshan earthquake area, which were relatively frequent.

  Since then, aftershock activity has significantly decayed, with only 5 aftershocks of magnitude 5 or higher (including this one). The last aftershock of magnitude 5 or higher occurred in 1995, 25 years ago.

  Which areas are within the scope of the old earthquake zone? Sun Shikun, a researcher at the China Earthquake Networks Center, said that the old earthquake area in Tangshan is relatively large, near Tianjin Ninghe in the south, Qinhuangdao and Luanzhou in the north. Small and medium earthquakes in this area are more common, including the Fengnan earthquake in December last year, which are all earthquakes in the area.

  In addition, the Beijing Earthquake Administration also said in an expert interpretation of the earthquake that the earthquake occurred in the aftershock area of ​​the Tangshan M7.8 earthquake in 1976. The seismic activity in the aftershock area of ​​Tangshan earthquake is very rich, showing a state of undulation and attenuation.

  Interpretation 3

  Will it cause a bigger earthquake?

  In the short term, it is unlikely that there will be more than 5 magnitude earthquakes in the old earthquake area

  After the earthquake occurred yesterday morning, the China Earthquake Network Center organized experts to conduct a special discussion on the earthquake activity. Experts believe that, based on current observations and analysis of earthquake cases, it is unlikely that an earthquake of magnitude 5 or more will occur again in the old earthquake area in a short period of time.

  According to Sun Shikun, at present, North China is still at a relatively low level of seismic activity. "Without entering a relatively active stage, the probability of frequent earthquakes is relatively low." He said that the major earthquakes that netizens are worried about are often accompanied by the process of continuous enhancement of multiple earthquakes before they occur. "Based on the above reasons, even if an earthquake occurs recently, there is a high probability that it will be an earthquake of magnitude 3 and magnitude 4," Sun Shimao said.

  According to the rapid damage assessment and preliminary on-site investigation, the impact of the Tangshan Guye earthquake can reach six degrees, and the seismic fortification intensity of the earthquake area is eight degrees. The study concluded that the earthquake caused significant damage to buildings.

  Beijing News reporter Ying Yue Zhao Pengle