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.

目前的板块构造理论允许在白垩纪早期以足够的细节重建不到一半的地球表面，这只是地球历史上最近的约 3%。 最大的未知数位于泛太平洋区域，这是一个现已消失的海洋区域，曾经覆盖地球约 70% 的面积。 该项目将根据地震层析成像（地幔地震图像）的新限制，建立一个新的泛太平洋板块重建项目，追溯到中生代。 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 空间分析这一基本但未充分利用的 STEM 技能，这是一项已确定的核心地球科学技能。 外展工作通过本科课程开发、与当地市中心一所 STEM 磁力高中的合作伙伴关系以及暑期本科生体验，优先接触历史上在科学领域代表性不足的群体。 该项目将为太平洋-Panthalassa 领域建立一个回溯到中生代的以断层扫描为主导的全板块重建，这将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。 使用非常规的断层扫描板重建工作流程，包括从断层扫描中对板进行 3D 映射、板展开（逆向变形），以及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系统比较，并使用成熟代码 CitcomS 和 TERRA 的既定工作流程，将其作为两种不同地球动力学正演建模方法的输入边界条件进行进一步测试。 由此产生的板块模型将提供地球一半以上的替代俯冲历史，可以在其他全球模型中进行模拟。 此外，该项目还探索了地震层析成像技术将深部地幔与地球表面连接起来以进行 4D 地球演化的能力和局限性，这支持了 NSF 构造学确定的关键研究前沿。该奖项反映了 NSF 的法定使命，并被认为是值得的通过使用基金会的智力优势和更广泛的影响审查标准进行评估来提供支持。