Systematic changes in the incoming plate structure at the Kuril trench
Systematic changes in the incoming plate structure at the Kuril trench
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DOI：
10.1029/2012gl054340
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发表时间：
2013-01-16
影响因子：
5.2
通讯作者：
Takahashi, Narumi
中科院分区：
文献类型：
--
作者：
Fujie, Gou;Kodaira, Shuichi;Takahashi, Narumi
最近在海沟外隆起区进行的地震构造研究表明，可能由于板块的弯曲和断裂，进入的大洋板块内的V-p向海沟方向有系统地减小。为了了解降低V-p的机制，V-s至关重要，因为V-p/V-s比值是岩性、孔隙度和流体存在的敏感指标。在Kuril海沟外隆起区，我们进行了广泛的地震折射和反射调查，揭示了V-p、V-s和V-p/V-s的系统变化。结果表明，进入洋板块的水含量向海沟方向增加，同时洋壳顶部出现与弯曲有关的裂缝，这与海水渗流一致。我们的研究结果支持了在海沟外隆起弯曲过程中板块弯曲和破裂在俯冲带水循环中起重要作用的观点。引用本文：Fujie， G.， S. Kodaira， M. Yamashita， T. Sato， T. Takahashi， N. Takahashi(2012)，千岛海沟入射板块结构的系统变化，地球物理学报。学报，40,88-93,10.1029/2012GL054340。
Recent seismic structural studies in trench-outer rise regions have shown that V-p within the incoming oceanic plate systematically decreases toward the trench, probably owing to bending and fracturing of the plate. To understand the mechanisms acting to reduce V-p, V-s is critical because the V-p/V-s ratio is a sensitive indicator of lithology, porosity, and the presence of fluid. In the outer rise region of the Kuril trench, we conducted an extensive seismic refraction and reflection survey that revealed systematic changes in V-p, V-s, and V-p/V-s. Our results suggest that water content within the incoming oceanic plate increases toward the trench accompanied by the development of bending-related fractures at the top of the oceanic crust, consistent with the seawater percolation. Our results support the idea that plate bending and fracturing during the bending in the outer rise of the trench play an important role in the water cycle of subduction zones. Citation: Fujie, G., S. Kodaira, M. Yamashita, T. Sato, T. Takahashi, and N. Takahashi (2012), Systematic changes in the incoming plate structure at the Kuril trench, Geophys. Res. Lett. 40, 88-93, 10.1029/2012GL054340.