面波反演苏北—南黄海盆地地壳三维S波速度结构  

Three-dimensional shear wave velocity structure of the Northern Jiangsu-South Yellow Sea Basin from Rayleigh wave tomography

作　　者：温燕林 于海英[1] 陈飞 方国庆 刘芳 WEN Yanlin;YU Haiying;CHEN Fei;FANG Guoqing;LIU Fang(Shanghai Sheshan National Geophysical Observatory,Shanghai 200062,China;State Key Laboratory of Marine Geology,Tongji University,Shanghai 200062,China;School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,Anhui,China)

机构地区：[1]上海佘山地球物理国家野外科学观测研究站,上海200062 [2]同济大学海洋与地球科学学院同济,上海200092 [3]中国科学技术大学地球和空间科学学院,安徽合肥230026

出　　处：《地震工程学报》2023年第1期130-137,180,共9页China Earthquake Engineering Journal

基　　金：上海科委科研计划项目(20dz1200500,14231202602);同济大学海洋地质国家重点实验室开放基金(MGK1827);上海佘山地球物理野外科学观测研究站开放基金(2020K07)。

摘　　要：区域地壳速度结构对于地震定位和地球动力学特征认识十分重要,一直是地震反演研究的主要内容。利用收集到的基于背景噪声面波成像方法的瑞利面波相速度数据,我们对苏北—南黄海地区地下三维S波速度结构开展了深度反演,进而探讨苏北—南黄海盆地地质结构与地震构造的关系。面波层析成像结果表明区域速度结构模型与地质特征基本一致,速度结构清晰刻画出了苏北—南黄海沉积盆地的主要沉积构造范围和基底起伏。反演结果还揭示了南黄海盆地中地壳内存在一显著的低速层,与历史强震集中分布区高度一致,表明浅源强震活动与壳内的低速层密切相关。The Northern Jiangsu-South Yellow Sea is underlain by the Yangtze Craton continental lithosphere. Based on the collected phase velocity data of Rayleigh surface wave, a depth inversion of the underground three-dimensional S-wave velocity structure in the Northern Jiangsu-South Yellow Sea area was carried out. Based on the data, the relationship between the geological structure and seismotectonics of the Northern Jiangsu-South Yellow Sea Basin was discussed. The surface wave tomography results show that the regional velocity structure model is basically consistent with the geological characteristics of the study area, and the velocity structure clearly depicts the main sedimentary structure range and basement fluctuation of the Northern Jiangsu-South Yellow Sea Basin. The inversion results also reveal that there is a remarkable low-velocity layer in the middle crust of the Northern Jiangsu-South Yellow Sea Basin, which is consistent with the concentrated distribution area of historically strong earthquakes, indicating that the activity of shallow strong earthquakes is closely related to the low-velocity layer in the crust.

关 键 词：VS 面波反演 苏北—南黄海盆地 地壳低速层 

分 类 号：P315[天文地球—地震学]