摘要
Abstract
An Ms5.2 earthquake occurred in Longyang District(24.91°N,99.26°E),Baoshan City,Yunnan Province,on May 2,2023,disrupting the relative seismic calm in Baoshan City,which had not experienced any Ms≥5.0 earthquakes since 2015.Based on field investigations of disaster losses and the collection of disaster data,this study provides a detailed analysis of the seismogenic geological structure,focal mechanism,spatial distribution of seismic intensity,and the earth-quake damage characteristics and causes in buildings and engineering structures in the Longyang area.Additionally,the earthquake damage matrix for buildings in the affected area was compared with the damage characteristics of historical earthquakes of similar magnitude in Yunnan Prov-ince.Results show that the epicenter of Longyang Ms5.2 earthquake is located in the middle seg-ment of the Lancang River fault zone,with right-lateral strike-slip,which is consistent with the result of the focal mechanism solution.The maximum intensity is Ⅵ degree,and the affected area is approximately 600 km2.The intensity circle presents an irregular ellipse with a long axis of 37 km and a short axis of 21 km.The long axis direction of the isoseismic line is NNW,aligning with the strike of the Lancang River fault,which is closest to the epicenter of the earthquake.Nine people were slightly injured in the earthquake,a number higher than typically seen in his-torical earthquakes of similar magnitude in Yunnan Province.The seismic performance of civil structure houses was poor,with notable damage observed.Due to site effects and the fact that some brick-concrete and frame structures were not constructed in accordance with specifications,the damage to houses in the area where the Wayao Town Government is located reached a severi-ty level of Ⅶ.Traffic,communication,and water conservancy facilities were damaged to differ-ent degrees,with traffic infrastructure suffering the most severe damage.Given the extensive damage,high casualties,serious building destruction,and significant economic loss caused by this earthquake,the study offers emergency response recommendations.These suggestions aim to improve earthquake prevention,disaster reduction,and emergency rescue capabilities in west-ern Yunnan,providing valuable reference for future preparedness and response strategies.关键词
隆阳Ms5.2地震/震害特征/震害成因Key words
Longyang Ms5.2 earthquake/characteristics of earthquake damage/causes of earth-quake damage分类
地球科学
