Red Star News:

Improving the seismic resistance of buildings is one of the effective ways to reduce damage from earthquake. We have noticed that the China Earthquake Administration (CEA) is organizing the compilation of a next-generation seismic ground motion parameter zonation map to provide national standards for construction and anti-seismic design. Could you please brief us on the details of this project? Thank you.

Wang Daoxi:

I will invite Mr. Wang Kun to answer this question.

Wang Kun:

Thank you for your question. China is a country prone to earthquake disasters and has a very complex geological structure, so the risk of seismic activity varies significantly from region to region. Seismic ground motion parameter zonation is the division of territories into several zones according to the degree of earthquake hazard, and to set different earthquake fortification requirements for each zone. The seismic zoning map mainly provides standards for the planning, site selection and earthquake fortification of general construction projects, as well as a basis for economic and social development planning, territorial space planning, urban and rural planning and the formulation of social preventive measures, as well as emergency preparedness and response.

China has developed five generations of seismic ground motion parameter zonation maps since 1957. The first three generations of seismic zoning maps were used as "references" and "basis," and the fourth and fifth generations were used as "mandatory national standards." Therefore, it can be seen here that our earthquake fortification requirements are constantly improving. In 2022, the CEA officially launched the compilation of a new-generation seismic zoning map. The new-generation seismic zoning map takes risk prevention as the overall objective, featuring "multi-probability, broadband, high precision and integration of land and sea." It is expected to be completed by the end of 2025. At the same time, the revision of Seismic Ground Motion Parameter Zonation Map of China, a mandatory national standard, will commence. At present, all work is progressing smoothly. First, the collection and collation of basic data has been generally completed. I will elaborate here with some data. We have built a basic database containing 14,000 destructive earthquake catalogs, 230,000 small earthquake catalogs and 11,000 sets of strong vibration observation records of 1942 earthquakes in China and neighboring areas. Second, we have completed a national seismic tectonic environment analysis and potential seismic source division, as well as have carried out the construction of three-dimensional seismic source models in strong seismic zones, such as the Tangshan earthquake and the Tancheng earthquake. Third, we have established a series of key models such as seismic activity, seismic motion prediction and site seismic motion, and have built technical methods for seismic ground motion hazard calculations. Fourth, we have carried out integrated pilot projects with key models and technologies in representative areas such as the North China Plain as well as Sichuan and Yunnan provinces, and have completed the seismic hazard calculations in pilot areas.

The new ground motion parameter zoning map is expected to improve the country's seismic safety standards, based on lessons from the 6.2-magnitude earthquake in Gansu's Jishishan, the 7.8-magnitude earthquake in Türkiye and the 7.3-magnitude earthquake in the Taiwan region's Hualien. For eastern China's supertall structures, densely populated large commercial complexes, and other facilities, we've placed greater emphasis on the effects of long-period ground motion and the amplification caused by deep sedimentary basin layers. In western China's regions with concentrated large fault zones, we've adopted a three-dimensional epicenter model and a corresponding ground motion model to more accurately assess seismic activity levels near active faults. In short, this new generation of zoning maps will give full play to scientific and technological innovation and the practical application of research outcomes. It will better serve earthquake resistance efforts in general construction projects and formulation of various response plans, while effectively supporting earthquake disaster risk identification, assessment, and the development of a more earthquake-resilient society. Thank you.