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早白垩世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~3%。最大的未知数位于潘特拉萨-太平洋区域，这是一个现已消失的海洋区域，曾经覆盖了地球约70%的面积。本项目将从地震层析成像的新约束--地震学成像的地球地幔--S地幔中重建一个回到中生代的新的潘塔拉萨-太平洋板块。这项研究与一项教育计划相结合，该计划的重点是使用地球内部成像来帮助发展3D空间分析的基本但未得到充分利用的STEM技能，这是一项已确定的核心地球科学技能。外展工作的重点是通过本科生课程开发、与当地市中心的STEM磁铁高中的合作伙伴关系以及通过暑期本科生体验，接触到历史上在科学界代表性不足的群体。该项目将为中生代以来的太平洋-泛地中海地区建立一个以层析成像为主导的全板块重建，这将为全球模型和区域研究提供依赖时间的运动学和构造边界条件。使用非传统的层析成像板重建工作流程，该工作流程涉及来自层析成像的板的3D映射、板展开(回溯变形)以及使用可用的运动学约束以分级方式将板运动分配给展开的板。将层析成像板块重建模型与环太平洋相关地质数据集进行了系统的比较，并使用成熟的CitcomS和Terra程序建立的工作流程，进一步测试了两种不同的地球动力学正演方法的输入边界条件。由此产生的板块模型将提供地球大半个地区的另一种俯冲历史，可以在其他全球模型中模拟。此外，该项目探索了地震层析成像在4D地球演化中将深部地幔连接到地球表面的能力和局限性，这支持了NSF构造的一个已确定的关键研究前沿。该奖项反映了NSF的法定使命，并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，被认为值得支持。