华北平原三河平谷关键构造部位地壳精细结构研究

伴随数值地震预报与大数据、人工智能在地震学的迅猛发展，对地壳精细结构成像的分辨率和可靠性提出了更高的要求。以首都圈为核心区的华北平原构造活动强烈，强震频发，查明该地区发震构造精细结构对深入理解大震孕育环境、发震机理，以及提升地震危险性评估能力十分关键。该区域已有成果主要来自42条二维人工震源探测剖面，通过合理的插值得到三维成像，剖面间的三维结果缺乏物理支撑，可靠性低，更缺少浅层地壳精滑脱构造三维精细结构，已不能满足迫切需求。本研究拟在充分继承现有成果的基础上，综合利用华北地区固定台网和流动台阵数据，在三河-平谷震区加密布设流动密集台阵；开展体波与噪声面波频散数据联合反演，实现浅层地壳精细滑脱层构造高分辨率成像；同时，综合已有的地质和地球物理资料及约束，揭示研究区强震区的发震构造精细特征，为研究区孕震动力学模型研究提供关键约束。

With the rapid development of numerical earthquake prediction, big data and artificial intelligence in seismology, the quality of the resolution and reliability for fine structure imaging results of the crust is required to be higher. The North China Plain with the capital Beijing as major metropolitan areas is characterized by frequent strong seismic and tectonic activities. Detailed understanding the fine crust structure in this area is crucial to exploring the mechanism of strong earthquakes and strengthening the abilities of earthquake disaster reduction, prevention and preparedness. However, existing 3D imaging results about fine shallow crust structure are obtained from 42 2D seismic wide-angle reflection/refraction profiles by Kriging interpolation, lacking of physical support and 3D fine structure of the shallow crustal detachment structure, which can no longer meet the urgent needs. This study intends to deploy a dense seismic array in the Sanhe-Pinggu seismogenic area, and make comprehensive use of the seismic data from permanent and portable stations. Based on the existing results from seismic wide-angle reflection/refraction profiles as the input model, the joint inversion of body wave and seismic ambient noise dispersion data is carried out to construct high resolution 3D shallow crustal detachment structure. Combined with the geological and geophysical information, the fine tectonic characteristics of the strong earthquake seismogenic area will be revealed, which can provide new insights into the seismogenic structure and seismogenic dynamic model.