潜在地震对我国南海开发和建设影响的初步考虑

Effects of Potential Earthquakes on Construction and Development in South China Sea Region

南海地区位于欧亚板块、太平洋板块和印度板块交汇处,地质构造十分复杂。考虑并关注潜在地震对南海区域的影响,可以有效降低地震带来的危害。我国目前已经建立了比较完备的陆地地区建、构筑物的抗震设计规范,但是针对海域的工程地震研究还比较少,地震动参数特征和地震动衰减规律尚是空白。基于上述考虑本文分析了南海及临区的地震构造,通过对历史地震资料分析表明:(1)南海北部历史上发生过7级以上大地震,该区域的近海工程要考虑琼粤滨海断裂带和红河断裂带引发的地震影响;(2)南海中部区域要更加关注台南至菲律宾吕宋岛西侧俯冲带的影响,该区域地震易发、多发,6级左右的中强震较多,强震和大震也偶有发生;(3)俯冲带地震与浅地壳地震的特征有一定差异,因而有必要对俯冲带板内、板缘地震做专门分析和研究。

The South China Sea （SCS）region is rich in oil,gas,and fishery resources,as well as po-tential tourism sites.With the establishment of the city of Sansha,traffic engineering,civil engi-neering,and infrastructure construction in the SCS have become the core of the economy.The SCS is located at the intersection of the Eurasia,Pacific,and Indian Plates and has a very complex geo-logical structure.Considering the impact of potential earthquakes on the development of the SCS region,steps need to be taken to mitigate their dangerous effects.China currently has established relatively complete seismic design codes for structures on land,but studies on offshore earthquake engineering are still rare,and attenuation strategies for offshore engineering are incomplete.This paper will analyze the seismotectonics of the SCS and its adjacent areas through analysis of histor-ical seismic data.The results show：（1 ）Earthquakes greater than magnitude 7 have occurred in the northern part of the SCS.Thus,offshore engineering in the region should consider the impact of earthquakes related to the Honghe and Qiongyue offshore fault zones.（2）In the central region of the SCS,the impact of the subduction zone from south Tainan to the west side of the Luzon Is-land in the Philippines should be taken into account.（3）The characteristics of subduction earth-quakes and shallow crustal earthquakes are different,and it is necessary to study the specific fea-tures of interface and intraslab earthquakes in a subduction zone.