Abstract:

Three-dimensional finite element modeling has been used to study the Japanese subduction zone.Contribution to the state of stress in the overriding and suboucting plate by plate push．slab pull,locked interplate fault and decoupling interplate earthquakes is analysed,respectively,The modeling results show that the push of the oceanic plate is the primary origin of the compressive stress in the trench-island arc region. Only a small portion of this stress transfers into the overriding plate.Creep of the asthenosphere can promote this stress transmission leading to stress increasing of the island arc region.Slab pull caused by density contrast produces both compressional and extensional stress in a diffuse pattern. The locked interplate fault determines the site of stress accumulation which is responsible for great coupling interplate earthquakes.Thrust faulting caused by an interplate earthquake can have evident influence over the regional stress state only to a small extent around the rupture.

Key words: The Japanese subduction zone, Stress generation, Stress transter, Three-dimensional numerical Modeling

摘要：

用三维有限元模拟了日本地冲带,分析了板块推力、板块拉力、动态闭锁断层和解耦板间地震对上覆板块内部应力状态的贡献,表明大洋板块推力是海沟。岛弧地区挤压应力的主要来源,这种应力仅有小部分传播到上覆板块内部,软流圈的蠕变能促进这个应力传播过程使岛弧区的应力增大,由密度差异引起的板块拉力产生了分散的挤压应力和拉张应力。断层闭锁导致应力局部集中,板间地震的断层错动只对破裂附近小范围的应力状态产生影响。

关键词: 日本俯冲带, 应力产生, 应力传播, 三维数值模拟