【摘要】 本文合成2021年玛多M_w 7.4地震的近断裂地震动场。首先,介绍基于频率波数域格林函数的地震动合成方法的计算原理和关键环节;构建玛多地区一维地壳速度结构模型,计算了区域不同深度与距离之间的格林函数;在分析不同机构确定的震源机制参数的基础上,选取了两个震源错动模型,计算了相应的上升时间和破裂时间分布;其次,合成有强地震动记录的16个中远场台站的三分量地震动,系统比较合成地震动和观测记录的时程、幅值和反应谱,据此论证本文合成方法的适用性;最后,合成了近断裂三分量地震动场,展示出玛多地震近断裂地震动的空间分布特征。更多还原

【Abstract】 This paper performs the ground motion simulation for the 2021 Maduo M_w 7.4 earthquake. First, the calculation principle and key aspects of the ground motion simulation method based on frequency-wavenumber Green’s function are introduced; the one-dimensional crustal velocity structure model of the Maduo area is constructed, and then the Green’s functions for different sets of depth and distance in the region are calculated; Based on the analysis of focal mechanism parameters determined by different research institutes, two source slip models are selected, and the corresponding rise time and rupture time distributions are calculated. Next, for the 16 moderate and far-field stations with strong-motion records, three-component ground motions at are simulated; the synthetics and the observations are systematically compared in term of time history, amplitude and response spectrum, which demonstrates the applicability of the simulation method in this paper. Finally, the three-component near-fault ground motion field is simulated, and then the spatial distribution characteristics of near-fault ground motion for the Maduo earthquake are studied.更多还原