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Global SH-wave propagation in a 2D whole Moon model using the parallel hybrid PSM/FDM method |
Xianghua Jiang1, Yanbin Wang1, Yanfang Qin2, Hiroshi Takenaka3 |
1 Department of Geophysics, School of Earth and Space Sciences, Peking University, Beijing 100871, China
2 Equipe de Ge´osciences Marines, Institut de Physique du Globe de Paris, 4 Place Jussieu, 75252 Paris Cedex 05, France
3 Department of Earth Sciences, Faculty of Science, Okayama University, 3-1-1 Tsushima-Naka, Kita-ku, Okayama 700-8530, Japan |
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Abstract 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 odels. Our numerical modeling show that the low-velocity pper crust plays significant role in the development of reverberating wave trains. Increasing frequency enhances he 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.
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Fund:National Natural Science Foundation of China (Grants 41374046 and 41174034). |
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[1] |
Yongge Wan, Zheng-kang Shen, Min Wang, Yuehua Zeng, Jichao Huang, Xiang Li, Huawei Cui, Xiwei Gao. Co-seismic fault geometry and slip distribution of the 26 December 2004, giant Sumatra–Andaman earthquake constrained by GPS, coral reef, and remote sensing data[J]. Earthquake Science, 2015, 28(3): 187-195. |
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