Collaborative Research: 3D Modeling of Subduction in the Pacific

PI将使用完全并行的Sepran有限元程序来生成高分辨率的俯冲带3D模型，这些模型可以用来克服2D模型的限制。3D方法将使他们能够研究沿走向变化的板片参数的影响，例如板片倾角、进入岩石圈的年龄、汇聚方向和速度，以及覆盖板块性质的横向变化。这种方法还将使他们能够量化沿走向楔形流的影响，这种流动很可能发生在板片边缘附近，或者当俯冲带几何形状的横向变化导致上覆楔形区的压力梯度时产生。这种合作努力将通过地震学和板块运动学的最佳可用局部观测来约束模型的几何形状。他们将使用楔形速度和各向异性结构的地震学观测来测试模型。要完成的主要科学目标是：1)将3D模型应用于选定的若干现今俯冲带，这些俯冲带的板片输入或可观测值沿走向变化显著；2)研究弧形平行流动对俯冲带边缘附近地幔楔形条件的影响。该项目的潜在更广泛影响包括培训密歇根大学、布朗大学和波士顿大学的三名研究生，作为这一努力的一部分。

The PIs will use the fully parallel Sepran finite element code to generate high resolution 3D models of subduction zones that can be used to overcome the limitations of 2D models. The 3D approach will allow them to investigate the influence of along-strike variations in slab parameters such as slab-dip, age of incoming lithosphere, direction and speed of convergence, and lateral variations in properties of the overriding plate. This approach will also allow them to quantify the influence of along-strike wedge flow, which is likely to occur near slab edges or can be generated when pressure gradients in the overlying wedge are induced by lateral variations in the subduction zone geometry. This collaborative effort will constrain the model geometry by the best available local observations from seismology and plate kinematics. They will test the models using seismological observations of wedge velocity and anisotropy structure. The main scientific goals to be accomplished are: 1) the application of the 3D models to a selected number of present-day subduction zones with significant along-strike variations in slab input or observables; 2) an investigation of the influence of arc-parallel flow on mantle wedge conditions near the edges of subduction zones. The potential broader impacts of this project involve the training of three graduate students will be trained as a part of this effort, at Michigan, Brown and Boston University.