Bending of the subducting oceanic plate and its implication for rupture propagation of large interplate earthquakes off Miyagi, Japan, in the Japan Trench subduction zone
Bending of the subducting oceanic plate and its implication for rupture propagation of large interplate earthquakes off Miyagi, Japan, in the Japan Trench subduction zone
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俯冲海洋板块的弯曲及其对日本宫城县附近日本海沟俯冲带大型板间地震破裂传播的影响
DOI：
10.1029/2004gl022307
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发表时间：
2005
影响因子：
5.2
通讯作者：
R. Hino
中科院分区：
文献类型：
--
作者：
A. Ito;G. Fujie;S. Miura;S. Kodaira;Y. Kaneda;R. Hino
我们介绍了日本海沟中部弧前区域宫城近海宽角折射和反射实验的结果。这里的板间大地震有两个破裂带：向陆破裂带和向沟破裂带。为了研究板块边界几何形状对破裂带分布的影响，我们从反射中确定了反射体的几何形状。俯冲洋板块在143.2°E附近倾角从5°增大到13°。海洋板块的这个弯曲点对应于向沟破裂带的东边缘。此外，另一个弯曲点可能存在于约142.3°E，这对应于向陆破裂带的东部边缘。海洋板块弯曲点与破裂带边缘的重合表明，板块边界几何形状的变化可能会影响板间地震在板块会聚方向上的破裂传播。
We present the results of an onshore–offshore wide‐angle refraction and reflection experiment off Miyagi, in the central Japan Trench forearc region. There are two rupture zones of large interplate earthquakes here: the landward rupture zone and the trenchward rupture zone. To examine the influence of plate boundary geometry on the distributions of the rupture zones, we determined reflector geometries from reflections. The subducting oceanic plate increases its dip from about 5° to 13° around 143.2°E. This bending point in the oceanic plate corresponds to the eastern edge of the trenchward rupture zone. Moreover, another bending point may be present at approximately 142.3°E, which corresponds to the eastern edge of the landward rupture zone. The coincidence between bending points in the oceanic plate and the edges of rupture zones suggests that changes in the plate boundary geometry may affect rupture propagation of interplate earthquakes in the direction of plate convergence.