玛多M W7.3地震同震滑动分布的三维有限元模拟分析

Three-Dimensional Finite Element Simulation Analysis of Coseismic Slip Distribution of Madoi M W7.3 Earthquake

首次构建2021年玛多M_(W)7.3地震三维有限元模型,分析同震滑动分布特征。首先解算高精度GNSS同震形变观测数据;然后建立玛多地震三维有限元模型,并用弹性半空间Okada模型验证其准确性;最后以40个近场和远场GNSS同震形变观测数据为约束,利用最小二乘法反演玛多地震同震滑动分布模型,从而模拟同震位移。结果表明,玛多地震引起的破裂主要分布在野马滩和黄河乡附近,最大滑动值约为3.4 m。该结果与现场考察结果一致,能够很好地解释GNSS同震形变观测数据。

For the first time,we construct a three-dimensional finite element model for the 2021 Madoi M_(W)7.3 earthquake to analyze the features of coseismic slip distribution.First,we process the high-precision GNSS coseismic deformation observations.Then,we construct a three-dimensional finite element model,which is validated by the elastic half-space Okada model.Finally,we invert the coseismic slip distribution model of the Madoi earthquake using the least squares method,by constraining 40 near-field and far-field GNSS coseismic displacement observations.The results show that the Madoi earthquake reptures with a maximum value of about 3.4 m are mainly distributed near the area of Yematan and Huanghe country.The results are consistent with the field investigation and can well explain the GNSS coseismic deformation observations.