Seismic intensity survey and housing safety hazard analysis of the M3.5 earthquake in Youxi County, Fujian Province

At 11:16 am on June 8, 2024, a magnitude 3.5 earthquake occurred in Youxi County, Sanming City, Fujian Province. After the earthquake, the Fujian Earthquake Agency quickly activated a Level V emergency response and dispatched a post-earthquake field work investigation team to the affected area. In cooperation with earthquake and emergency management departments at the city and county levels, the team conducted intensity surveys at 35 survey points within the earthquake-affected area. The surveys enabled determination of the macroscopic intensity and macroscopic epicenter, as well as delineation of the isoseismal contour of macroscopic intensity. Using drone technology, the investigation identified brick-concrete structures and column-and-tie timber frame structures as the predominant housing types in the earthquake-stricken areas. Based on these findings, further analysis was conducted to identify weak points in seismic fortification and potential safety hazards in rural residential buildings in the affected areas.