柴达木盆地区域地震波传播特征研究

由于以往观测资料限制，柴达木盆地地区区域地震波传播特征研究工作亟待深入。本项目基于柴达木盆地地区首次获得的大量区域地震观测资料和数值模拟，揭示盆地地区区域地震波传播特征。通过所获得的分布于不同场地和位置的大量观测波形数据，分析峰值、持续时间、频谱等地震地面运动特征及其空间变化。收集地质和地球物理资料，建立柴达木盆地三维精细结构模型。对Mw6.3级主震及两个余震分别开展三维地震波传播数值模拟，通过和观测资料的对比分析，揭示柴达木盆地内复杂区域地震波传播过程。讨论柴达木盆地复杂盆地形状、巨厚松软沉积层、盆地边缘形状与断裂分布、地形起伏、传播路径、不同震级的震源过程对区域地震波传播的作用。通过上述研究，为这一以往观测数据缺乏地区的区域地震波传播研究提供新的认识，为沉积盆地地震地面运动研究提供新的例证，同时为这一重要经济区的抗震防灾提供重要参考。

Regional seismic wave propagation at Qaidam basin is relatively less understood because of the lacking of regional seismic observation data. Based on the first regional network seismic observation obtained at Qaidam basin and numerical modelling, this study is trying to study in detail the characteristics of regional seismic wave propagation at Qaidam basin. The peak velocity, duration and spectrum feature of the three component seismograms and their spatial variation will be analyzed firstly. Then the three dimensional structure model of Qaidam basin will be constructed with collected geological and geophysical data. Based on the model, three dimensional numerical modeling of seismic wave propagation will be performed for the Mw6.3 main shock and two aftershocks, respectively. The complex seismic wave propagation process at Qaidam basin is then investigated by comparing the synthetics with observations. Effects of basin geometry, soft and thick sedimentary layer, boundary shape and faults, topography, propagation path, source process of earthquakes with different magnitudes on regional seismic wave propagation will be investigated. Results of this study will enhance our understanding of regional seismic wave propagation at Qaidam basin, a region with few observations before. It also prove another good example for seismic ground motion study at sedimentary basin. It serves as an important reference for earthquake disaster reduction at Qaidam basin, an important economic region, as well.