Detectability analysis of interplate fault slips in the Nankai subduction thrust using seafloor observation instruments
Detectability analysis of interplate fault slips in the Nankai subduction thrust using seafloor observation instruments
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DOI：
10.1007/s11001-019-09380-y
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发表时间：
2019-02
影响因子：
1.4
通讯作者：
R. Agata;T. Hori;K. Ariyoshi;T. Ichimura
中科院分区：
文献类型：
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作者：
R. Agata;T. Hori;K. Ariyoshi;T. Ichimura
为了帮助决策在海底放置新的观测仪器，我们使用海底观测仪器检查了日本南开俯冲推覆中板间地震和慢滑的可探测性。这里，可探测性定义为基于地壳形变模拟的假设观测点探测到的板间断层滑动的最小震级。在可探测性分析中，我们考虑了与海底观测特别相关的传感器漂移的影响。此外，为了考虑南开海槽周围地形和三维非均匀地壳结构的影响，我们引入了高分辨率的地壳形变三维有限元模拟。可探测性分析结果表明，在南开地区引入新的海底倾斜观测台站，应能显着提高中小尺度板间地震和慢滑的可探测性。在此基础上，讨论了现有观测仪器和新型观测仪器在探测板间断层滑动方面的优势。
To help the decision making regarding where to locate new observation instruments on the seafloor, we examined the detectability of interplate earthquakes and slow slips in the Nankai subduction thrust in Japan using seafloor observation instruments. Here, the detectability is defined as the smallest magnitude of the interplate fault slip detected by the assumed observation points based on crustal deformation simulation. In the detectability analyses, we considered the effect of sensor drifts that are particularly associated with seafloor observations. In addition, we introduced high-resolution three-dimensional (3D) finite element modeling of crustal deformation to consider the effect of the topography and 3D heterogeneous crustal structure around the Nankai Trough. The results of the detectability analyses show that introducing new seafloor stations for tilt observation in the Nankai region should increase the detectability of small- or medium-sized interplate earthquakes and slow slips significantly. Based on the obtained results, we also discuss the advantage of both the existing and the new observation instruments in detecting interplate fault slips.