Strike-slip motion of a mega-splay fault system in the Nankai oblique subduction zone
Strike-slip motion of a mega-splay fault system in the Nankai oblique subduction zone
复制标题
南开斜俯冲带大扇断层系统的走滑运动
DOI：
10.1186/1880-5981-66-120
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Y. Ikeda
中科院分区：
文献类型：
--
作者：
T. Tsuji;J. Ashi;Y. Ikeda
我们从反射地震剖面、高分辨率海底测深和深拖曳海底剖面评价了板块运动的沟槽平行分量对南开增生楔体内活动断裂系统的影响。我们的研究表明，斜板俯冲的大部分海沟平行分量是通过沿位于巨型展布断层向陆地并向下倾斜的断层的走滑运动释放的。展布断裂系统的浅部形成花状构造，似乎适应了主要的走滑运动，而大多数倾滑运动可以传播到向海沟方向的解体。在走滑断层周围发育了大量裂缝，释放了困在巨型展布断层下的超压孔隙流体。裂缝发育可能与增生楔体内部应力方向的改变有关。因此，位于内外楔体交界处的走滑断裂是控制吸积棱柱内部应力状态(包括孔隙压力)的关键构造。此外，走滑运动有助于加强与南开海槽平行延伸约200公里的连续巨型断裂系统(外脊)。
We evaluated the influence of the trench-parallel component of plate motion on the active fault system within the Nankai accretionary wedge from reflection seismic profiles, high-resolution seafloor bathymetry, and deep-towed sub-bottom profiles. Our study demonstrated that a large portion of the trench-parallel component of oblique plate subduction is released by strike-slip motion along a fault located just landward of and merging down-dip with a mega-splay fault. The shallow portion of the splay fault system, forming a flower structure, seems to accommodate dominant strike-slip motion, while most of the dip-slip motion could propagate to the trenchward décollement. Numerous fractures developed around the strike-slip fault release overpressured pore fluid trapped beneath the mega-splay fault. The well-developed fractures could be related to the change in stress orientation within the accretionary wedge. Therefore, the strike-slip fault located at the boundary between the inner and outer wedges is a key structure controlling the stress state (including pore pressure) within the accretionary prism. In addition, the strike-slip motion contributes to enhancing the continuous mega-splay fault system (outer ridge), which extends for approximately 200 km parallel to the Nankai Trough.
2004 年苏门答腊地震的上倾破裂被厚厚的硬质沉积物扩展
影响因子：
18.3
作者：
Gulick S
通讯作者：
Gulick S