2008年青海大柴旦M_W6.3地震地面运动模拟  

Three-dimensional numerical modeling of seismic ground motion of 2008 M_W6.3 Da-Qaidam earthquake in Qinghai Province

作　　者：陈彦阳 王彦宾[1] 古村孝志 CHEN YanYang;WANG YanBin;Takashi Furumura(Department of Geophysics,School of Earth and Space Sciences,Peking University,Beijing 100871,China;Earthquake Research Institute,The University of Tokyo,1-1-1 Yayoi,Bunkyo-ku,Tokyo,113-0032,Japan)

机构地区：[1]北京大学地球与空间科学学院地球物理系,北京100871 [2]东京大学地震研究所,东京113-0032,日本

出　　处：《地球物理学报》2019年第12期4633-4647,共15页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41674052)资助

摘　　要：2008年11月10日在青海柴达木盆地北缘发生了大柴旦M W6.3地震,为了研究该地震的区域地震波传播与地面运动特征,本文利用地质资料和地壳速度结构研究成果,构建了柴达木盆地及周边区域三维传播介质模型,采用有限差分方法模拟了大柴旦地震波场传播过程以及地面运动分布特征.结果表明,柴达木盆地对波场传播有明显影响,表现为地震波传入盆地后在边界产生次生面波,盆地沉积物对地震波具有围陷作用,地震地面运动在盆地内振幅增大、持时延长.模拟结果给出的地震地面运动峰值速度分布以及理论地震图均和观测结果符合较好,反映数值模拟较好地给出了观测地面运动的主要特征以及传播介质模型的合理性.An earthquake with magnitude of M W6.3 occurred on 10 Nov 2008 at Da-Qaidam which is close to the northern edge of Qaidam basin.In order to investigate seismic wave propagation and ground motion characteristics of this earthquake,we constructed three dimensional transmission medium model of Qaidam basin and adjacent area based on previous geological and geophysical survey results.Using parallel finite different method,we conducted three dimensional numerical modeling of seismic wave propagation and ground motion amplification in Qaidam basin for the Da-Qaidam earthquake.Modeling results show that Qaidam basin has significant effect on regional seismic wave propagation.Large amplitude secondary surface waves are generated at basin edge and seismic waves are trapped inside of the basin,which cause amplitude amplification and duration elongation of ground motion inside of the basin.Peak ground velocity and synthetic seismograms from simulation agree well with the observations,which suggests that our model and numerical calculation could reveal the major features of observed ground motion.

关 键 词：地震波传播 地震地面运动 数值模拟 柴达木盆地 大柴旦地震 

分 类 号：P315[天文地球—地震学]