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冲绳板块位于菲律宾海板块向欧亚板块俯冲形成的西太平洋边缘活动带上,构造应力场图像及其动力学机制表现得相当复杂.采用伪三维有限元方法,以WSM2008观测应力场数据的应力取向和应力型两方面指标作为主要约束,对冲绳板块构造应力场进行了数值模拟.通过对计算结果的分析,对模型涉及的各种作用力作出了估计.在此基础上,对冲绳板块岩石层的状态,以及该地区的板块动力学特征进行了探讨,并得到了以下一些初步认识:①软流层静压推力控制着该地区构造应力场的基本形态;②冲绳海槽的演化过程,例如该地区的岩石层减薄与其下地幔流的上升等,也在很大程度上影响了该地区的板内应力场空间分布特征;③琉球俯冲带边界力的作用是分段的,不同区段作用力对板内应力场的影响有所不同.
The Okinawa plate is located on the active belt of the western Pacific margin formed by subduction of the Philippine Sea plate to the Eurasian plate, and the image of tectonic stress field and its dynamic mechanism are quite complicated. The pseudo-3D finite element method is used to observe the stress orientation of stress field data by WSM2008 And stress type as the main constraints, the tectonic stress field of Okinawa plate is numerically simulated.Based on the analysis of the calculated results, the various forces involved in the model are estimated.On this basis, the Okinawa plate rock strata And the dynamic characteristics of plate tectonics in the area are discussed. Some preliminary understandings are obtained as follows: (1) The hydrostatic thrust of the asthenosphere controls the basic configuration of the tectonic stress field in the area; (2) the evolution of the Okinawa Trough, for example The thinning of lithosphere in the area and the rise of its lower mantle flow also affect the spatial distribution of in-situ stress field in the area to a large extent. (3) The boundary force of Ryukyu subduction zone is segmented, and different sections The effect of force on the stress field in the plate is different.