西太平洋俯冲带岩石圈变形研究

全球海洋岩石圈的最大弯曲与大地震发生在俯冲带。当弯曲应力超过岩石承受范围，就会产生正断层和地震，海水沿着正断层进入上地幔并发生蛇纹石化，引发浅源地震并可能造成灾难性海啸。选取西太平洋最具代表性的日本、伊豆-小笠原、马里亚纳和雅浦俯冲带以及汤加-克马德克俯冲带，归纳近些年的地球物理观测及地球动力学模拟的结果，对比分析了不同俯冲带挠曲正断层的分布特征，并探讨了俯冲板块变形与地震之间的相关性,以揭示俯冲板片弯曲变形及相应的正断层与潜在板块水化特征。

Lithospheric deformation in western Pacific subduction zones

The greatest flexural bending of the oceanic lithosphere and major earthquakes occur at subduction zones. When the bending stresses exceed the rock yield strength, pervasive normal faulting and extensional earthquakes would be generated within subducting plates. Normal faulting provides conduits for fluids to reach the upper mantle and facilitates serpentinization. Extensional earthquakes could also trigger tsunamis. Thus, better understanding flexural bending, stress distribution, and brittle failure of the subducting plate is essential to study the mechanism of earthquake and Earth's water cycle. Based on summary of geophysical observations and geodynamic simulations of the most representative Japan, Izu-Bonin, Mariana and Yap subduction zone and Tonga-Kermadec subduction zone in the western Pacific Ocean, this paper presents overview of characteristics of plate bending, bending-related normal faulting and corresponding brittle yield zone. The distribution characteristics of bending-related normal faults in different subduction zones were analyzed, and the correlations between plate deformation and earthquakes were discussed. It reveals the potential plate hydration characteristics of bending plates with normal faults. This study provides a basis for the future research on the plate deformation mechanism of subduction zones.