南海及邻区地壳上地幔三维S波速度结构的面波波形反演

摘要

We assembled approximately 328 seismic records. The data set was from 4 digitally recording long-period and broadband stations of CDSN. We carried out the inversion based on the partitioned waveform inversion (PWI). It partitions the large-scale optimization problem into a number of independent small-scale problems. We adopted surface waveform inversion with an equal block (2°×2°) discretization in order to acquire the images of shear velocity structure at different depths (from surface to 430 km) in the crust and upper-mantle. The resolution of all these anomalies has been established with “check-board” sensitivity tests. These results show significant difference in velocity, lithosphere and asthenosphere structure between South China Sea and its adjacent regions.%对南海及邻区中国数字地震台网4个台站接收到的328条长周期地震记录的面波波形进行分块波形反演．分块波形反演把大尺度的优化问题转化为小尺度的优化问题，采用非线性优化方法求解，从而得到南海及邻区2°×2°网格划分、从地表深至430 km的地壳上地幔三维S波速度结构，并用“检验板”法进行了分辨率分析．结果表明，海域、岛弧和大陆在速度分布、岩石圈和软流圈存在明显的结构差异．