China News Service, Beijing, October 26 (Reporter Sun Zifa) The reporter learned from the China Earthquake Administration on October 26 that after a 7.0-magnitude earthquake occurred in Baqing County, Nagqu City, Tibet Autonomous Region on the night of October 22, the seismic system went all out to carry out professional monitoring and work together to provide earthquake relief.
Weaving a professional monitoring network on the Northern Tibetan Plateau
The China Earthquake Administration immediately launched an emergency response to the Level 2 earthquake, forming an on-site team of 72 experts, carrying mobile observation equipment and gathering at night to advance to the front lines of the earthquake zone on the snowy plateau.
The northern Tibetan Plateau where the earthquake is located is sparsely populated, extremely cold and hypoxic, with an average altitude of nearly 4,800 meters. The harsh natural conditions pose severe challenges to earthquake emergency response. The disaster situation is an order, and the seismic system is united to carry out on-site earthquake emergency response and weave a professional monitoring network on the northern Tibetan Plateau.
The Seismological Bureau of the Tibet Autonomous Region, the Seismological Bureau of Qinghai Province, and the First and Second Monitoring Centers of the China Earthquake Administration dispatched 6 mobile monitoring teams carrying 17 sets of seismic measurement and Global Navigation Satellite System (GNSS) observation equipment to the earthquake area. On the Qinghai-Tibet Plateau, team members raced against time to urgently deploy mobile observation equipment, keep a close eye on aftershocks and surface deformation dynamics, and collect measured data.
The earthquake area has a high altitude and harsh natural environment, making it extremely difficult to conduct earthquake emergency mobile observations. The on-site team members inherited the tradition of people suffering from plateau earthquakes who "do not lack spirit even if they are deprived of oxygen" and worked in remote pastoral areas and even uninhabited areas. At points above 4,800 meters above sea level, vehicles cannot pass. The GNSS team members carried dozens of kilograms of instruments on their backs to carry out the survey on foot, moving forward on the steep slopes.
In order to "complete the installation of the instruments one minute earlier, the monitoring of the earthquake area will be more secure", the team members endured altitude sickness, made every effort to seize the observation window period to carry out intensive observations, and completed various tasks of site selection, debugging, and data collection in strict accordance with technical specifications.
As of October 25, the on-site earthquake monitoring team in the Baqing earthquake area had completed the installation of all 9 seismic measurement stations and 6 GNSS stations. As a set of instruments has gained a foothold on the snowy plateau, the earthquake monitoring capability within 50 kilometers of the epicenter has been increased from the original level 2.5 to level 1.0, ensuring that first-hand measured data is continuously transmitted back, providing solid data support for the study and judgment of earthquake trends.
Gathering a powerful force for earthquake relief
Accurately determining the scope and extent of earthquake damage is one of the core tasks of earthquake emergency on-site work. The high altitude, low temperature, long distance, and difficult access of survey points in earthquake areas pose challenges to on-site investigation work. The on-site command headquarters formed 13 intensity assessment teams. Members of each team worked continuously despite high temperatures and strong winds and lack of oxygen, and went to various disaster-stricken towns to conduct field investigations.
In view of the fact that most of the houses in the earthquake area are adobe civil structures, the survey points are scattered, and the intensity survey is extremely difficult, as soon as the team members of the China Earthquake Disaster Prevention Center arrived at the epicenter, they went deep into the extreme earthquake zone to carry out work. The daily journey took nearly 7 hours. Many team members suffered from severe altitude sickness, but they still continued to work in the field. After several days of continuous work, the team members discovered the surface rupture zone of the earthquake for the first time. They also found many earthquake damage phenomena such as sand liquefaction and ground cracks, which provided important basis for drawing intensity maps.
A team from the China Earthquake Administration's Institute of Engineering Mechanics went to the epicenter of the earthquake to assess the damage characteristics of houses and conduct on-site surveys of damage to roads, bridges and other infrastructure to collect first-hand valuable information for disaster assessment. Team members from the Tibet Autonomous Region Earthquake Administration traveled through the earthquake-stricken villages, investigating residential and public buildings one by one, and controlling the Humans and machines surveyed the surface rupture zone near the epicenter to capture the traces left by the earthquake; team members from the seismological bureaus of Sichuan, Yunnan, and Gansu provinces went to many counties and towns in the earthquake area, visited villages and households to check the cracks in house walls and damage to components, collected earthquake damage information, and worked overtime at night to summarize and compare various data to ensure that the intensity assessment results were scientific and rigorous.
Because the earthquake was close to Zaduo County in Qinghai Province, it also caused disasters in some towns and villages in Zaduo County. The Qinghai Provincial Seismological Bureau team went deep into the earthquake area, carefully measured deformation traces in the wilderness, and went into the countryside to record the damage to houses.
At 191 survey points dotted on the plateau, the seismic system on-site team overcame the high cold and hypoxia and ran around the villages and pastures for days to measure the earthquake area with their feet. The cracked earth walls and cracks in the earth were all carefully recorded to professionally investigate and restore the true damage of the earthquake.
According to the China Earthquake Administration, field team members have been traveling in the vast Qiangtang for several days, covering a total of more than 20,000 kilometers. First-hand earthquake damage information such as house damage and surface deformation collected from survey points in various towns and villages in the earthquake area has been continuously collected, providing strong support for the drawing of earthquake intensity maps.
While intensively carrying out mobile observations and earthquake damage investigations, front-line team members also went to resettlement sites to conduct popular science education on aftershock prevention knowledge and risk-avoidance skills, and provided post-earthquake psychological counseling.
In the capital Beijing, thousands of miles away from the earthquake zone, in the emergency command hall of the China Earthquake Administration, the personnel on duty at the China Seismological Network Center kept an eye on the real-time waveforms. Rounds of earthquake situation consultations continued to analyze and judge the dynamics of aftershocks in a timely manner. Researchers from the China Earthquake Administration's Institute of Geophysics, Institute of Geology, and Institute of Earthquake Prediction worked against time to expedite the production of technical maps of historical earthquakes around the epicenter, focal mechanism solutions, source rupture processes, and precise positioning of aftershocks, gathering a powerful force for earthquake relief.
