CAREER: Unfolding Earth history back to the Mesozoic by incorporating seismic tomography into Pacific realm plate tectonic reconstructions

目前的板块构造理论允许不到一半的地球表面在白垩纪早期得到足够详细的重建，这只是地球历史的最近的3%。最大的未知区域位于泛海太平洋区域，这是一个现已消失的海洋区域，曾经覆盖了地球的70%。该项目将根据地震层析成像的新约束-地球地震图像-建立一个新的泛海-太平洋板块重建，追溯到中生代。地幔。该研究与一项教育计划相结合，该计划侧重于使用地球内部成像来帮助开发3D空间分析这一重要但未充分利用的STEM技能，这是一项已确定的核心地球科学技能。拓展工作的重点是通过本科课程开发、与当地市中心一所STEM高中的合作伙伴关系，以及通过暑期本科体验，接触到在科学领域历史上代表性不足的群体。该项目将建立一个以层析成像为主导的、完整的中生代太平洋-泛海区域板块重建，为全球模型和区域研究提供随时间变化的运动学和构造边界条件。使用了一种非常规的层析板重建工作流程，包括从断层扫描中对板进行3D映射，板展开（反向变形），并使用可用的运动学约束以分层方式将板运动分配给展开的板。将层析板重建模型与相关环太平洋地质数据集进行了系统比较，并使用成熟代码CitcomS和TERRA的既定工作流程，作为两种不同的地球动力学正演建模方法的输入边界条件进行了进一步测试。由此产生的板块模型将为地球一半以上的地区提供另一种俯冲历史，可以用其他全球模型来模拟。此外，该项目还探讨了地震层析成像在将深部地幔与地球表面联系起来进行四维地球演化的能力和局限性，这为NSF构造学确定的关键研究前沿提供了支持。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Current plate tectonic theory permits less than half of the Earth surface to be reconstructed with adequate detail by the early Cretaceous, which is only the most recent ~3% of Earth history. The largest unknowns lie within the Panthalassa-Pacific realm, a now-vanished oceanic domain that once covered ~70% of the Earth. This project will build a new Panthalassa-Pacific plate reconstruction back to Mesozoic times from the novel constraints of seismic tomography - seismological images of the Earth?s mantle. The research is combined with an educational plan that focuses on using Earth interior imaging to help develop the essential but underutilized STEM skill of 3D spatial analysis, an identified core geoscience skill. Outreach efforts prioritize reaching groups historically underrepresented in the sciences via undergraduate curriculum development, a collaborative partnership with a local inner-city STEM magnet high school, and through summer undergraduate experiences. This project will build a tomography-led, full plate reconstruction for the Pacific-Panthalassa realm back to the Mesozoic era that will contribute time-dependent kinematic and tectonic boundary conditions for global models and regional studies. An unconventional tomographic plate reconstruction workflow is used that involves 3D mapping of slabs from tomography, slab unfolding (retro-deformation), and assigning plate motions to the unfolded slabs in a hierarchical fashion using available kinematic constraints. The tomographic plate reconstruction model is systematically compared to relevant circum-Pacific geological datasets, and further tested as input boundary conditions for two distinct geodynamic forward modeling approaches using established workflows for the mature codes CitcomS and TERRA. The resulting plate model will provide an alternative subduction history for more than half of the Earth that can be simulated within other global models. In addition, the project explores the capabilities and limitations of seismic tomography for linking the deep mantle to the Earth surface for 4D Earth evolution, which supports an identified key research frontier for NSF Tectonics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.