Global SH-wave propagation in a 2D whole Moon model usingthe parallel hybrid PSM/FDM method
Global SH-wave propagation in a 2D whole Moon model usingthe parallel hybrid PSM/FDM method
复制标题
使用并行混合 PSM/FDM 方法在二维全月球模型中传播全局 SH 波
DOI：
10.1007/s11589-015-0121-4
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发表时间：
2015
影响因子：
1.2
通讯作者：
Hiroshi Takenaka
中科院分区：
文献类型：
--
作者：
Xianghua Jiang;Yanbin Wang;Yanfang Qin;Hiroshi Takenaka
我们目前的SH波传播的数值模拟最近提出的整个月球模型，并试图提高我们的理解月球地震波传播。采用交错网格下的PSM/FDM混合方法求解波动方程，并在PC机群上实现计算，提高了计算效率。首次讨论了100 km浅源月震和900 km深源月震的全球SH波传播特征。然后用不同的模型研究了频率范围和地壳厚度横向变化的影响。最后，我们的合成波形与观测到的阿波罗数据进行比较，以显示波传播的功能，我们的模型产生的和那些没有重现我们的模型。数值模拟结果表明，低速上地壳对混响波列的形成起着重要作用。增加频率会增强混响的强度和持续时间。浅层地震波场以表层多次波为主。低频深地震的核幔反射特征清晰可辨。分层的全月模型和低速的上地壳产生的混响波列的每个阶段与观测一致。然而，更现实的月球模型应考虑，以解释观测数据上显示的各阶段之间的强和慢衰变散射。
We present numerical modeling of SH-wave propagation for the recently proposed whole Moon model and try to improve our understanding of lunar seismic wave propagation. We use a hybrid PSM/FDM method on staggered grids to solve the wave equations and implement the calculation on a parallel PC cluster to improve the computing efficiency. Features of global SH-wave propagation are firstly discussed for a 100-km shallow and 900-km deep moonquakes, respectively. Effects of frequency range and lateral variation of crust thickness are then investigated with various models. Our synthetic waveforms are finally compared with observed Apollo data to show the features of wave propagation that were produced by our model and those not reproduced by our models. Our numerical modeling show that the low-velocity upper crust plays significant role in the development of reverberating wave trains. Increasing frequency enhances the strength and duration of the reverberations. Surface multiples dominate wavefields for shallow event. Core–mantle reflections can be clearly identified for deep event at low frequency. The layered whole Moon model and the low-velocity upper crust produce the reverberating wave trains following each phases consistent with observation. However, more realistic Moon model should be considered in order to explain the strong and slow decay scattering between various phases shown on observation data.