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

职业：通过将地震层析成像纳入太平洋板块构造重建，将地球历史追溯到中生代

• 批准号: 2422671
• 负责人: Jonny Wu
• 金额: $ 56.83万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-10-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2422671&HistoricalAwards=false
• 关键词: CAREER; Unfolding; Earth; history; back

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.

当前的板块构造理论允许不到一半的地球表面被早期白垩纪的充分细节重建，这仅是最近〜3％的地球历史。 最大的未知数位于Panthalassa-Pacific领域，这是一个曾经覆盖的海洋领域，曾经占地约70％。 该项目将建立一个新的Panthalassa -Pacific板块重建，回到中生代，这是从地震层析成像的新约束 - 地球地震的地震图像。 这项研究与一项教育计划结合使用，该计划着重于使用地球室内成像，以帮助发展3D空间分析的基本但未充分利用的STEM技能，这是一种已确定的核心地球科学技能。 外展工作优先考虑通过本科课程发展，与当地市中心STEM磁铁高中的合作伙伴关系以及整个夏季的本科生经验，将历史上的人数不足。 该项目将为Pacific-Panthalassa领域建立一个主导的，完整的板块重建，回到中生代时代，将为全球模型和区域研究贡献时间依赖时间的运动学和构造边界条件。 使用了一个非常规的层析成像板重建工作流，该工作流程涉及从层析成像，平板展开（复古形成）和使用可用运动学约束的层次形式的3D映射。 层析成像板重建模型与相关的圆周地质数据集进行了系统的比较，并使用成熟的代码CITCOM和Terra的已建立工作流程进一步测试了两种不同的地球动力学前向模型方法的输入边界条件。 所得的板模型将为超过一半的地球提供替代的俯冲历史，该历史可以在其他全球模型中进行模拟。 此外，该项目还探讨了地震层析成像的能力和局限性，将深层地幔与地球表面联系起来，以实现4D地球进化，该地球表面支持NSF Tectonics的一项确定的关键研究边界。该奖项反映了NSF的法定任务，并通过使用该基金会的知识优点和广泛的影响来评估NSF的法定任务，并被认为是值得通过评估的支持。