CSEDI Collaborative Research: Deciphering the LLSVP-plume relationship

CSEDI 合作研究：破译 LLSVP-羽流关系

• 批准号: 1900652
• 负责人: Matthew Jackson
• 金额: $ 9.87万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-05-01 至 2023-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1900652&HistoricalAwards=false
• 关键词: CSEDI; Collaborative; Research; Deciphering; LLSVP

Much of our view of mantle evolution is shaped by our current knowledge of mantle convection and plume dynamics; examples include hotspot volcanism--including large igneous provinces--and mantle mixing. By gaining a deeper understanding of how, where, and why plumes form, and their composition and their relationship to the deep interior's large low shear wave velocity structures (LLSVPs) under Africa and the Pacific, the PIs will make a significant step towards understanding the dynamical and geochemical evolution of the mantle. Their efforts should provide a basis to better understand the three-dimensional flow structure surrounding LLSVPs and where, how, and why plumes form. This may help answer the question: How is the relationship between plumes and LLSVPs reflected in hotspot lavas such as those found in Hawaii? The new research directions will enrich cross-fertilization between the fields of mantle dynamics and geochemistry and contribute to the growing body of work on mantle plumes and LLSVPs. The PIs are engaged in a number of activities aimed at education and training at all levels. The PIs have and will continue to engage undergraduate students, including those from underrepresented groups in their research activities. As part of this proposal the PIs aim to augment the content associated with related Wikipedia entries and develop a series of educational films to post on specifically dedicated YouTube channels. The lab lends itself to site visits by elementary, middle school and high school students. PI Lithgow-Bertelloni intends to continue providing lab tours and opportunities for elementary and middle-school children to be involved in simple experiments.Amongst the most enigmatic aspects of the Earth's deep interior are the anomalous large low shear wave velocity provinces (LLSVPs) under Africa and the Pacific. The origin, composition, and dynamics of these provinces remain controversial. For example, it has been suggested that plumes predominantly form at the edges of LLSVPs and that entrained material from LLSVPs explains the distinct chemical asymmetries found at certain hotspots. The PIs are proposing an experimental fluid dynamical study to explore how three proposed LLSVP structures control and interact with mantle plumes. These three structures represent the range of LLSVP formation hypotheses so far proposed: a) purely thermal; b) dense and deformable; c) undeformable and uncoupled. They will use state-of-the-art visualization tools, including scanning particle image velocimetry and thermometry to measure the three-dimensional temperature and flow fields, laser induced fluorescence, and Lagrangian analysis tools to locate plumes and quantify entrainment to very high spatial and temporal resolutions. The PIs seek to test both location control and whether entrainment at the edges explains the observed chemical asymmetry in hotspot lavas.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.

我们对地幔进化的大部分观点是我们当前对地幔对流和羽流动态的知识所塑造的。例子包括热点火山，包括大火成岩省 - 和地幔混合。通过对非洲和太平洋领导下的深层内部大型低剪切波速度结构（LLSVP）的形式，它们与它们与深层内部大型低剪切波速度结构（LLSVP）的关系以及它们的组成以及它们的关系有了更深入的了解，PI将迈出重要的一步。他们的努力应提供一个基础，以更好地理解LLSVPS周围的三维流量结构以及羽毛形成的位置，如何和为什么形成。这可能有助于回答以下问题：在夏威夷类似的热点熔岩中，羽毛和LLSVP之间的关系如何反映？新的研究方向将丰富地幔动力学和地球化学领域之间的交叉施用，并为地幔李子和LLSVPS上的工作不断增长做出贡献。 PI从事各种旨在各级教育和培训的活动。 PI已并且将继续吸引本科生，包括来自代表性不足的小组的研究活动。作为本提案的一部分，PI旨在扩大与相关的Wikipedia条目相关的内容，并开发一系列教育电影，以发布专门专门的YouTube频道。该实验室将小学，中学和高中生的现场访问提供。 Pi Lithgow-Bertelloni打算继续为中小学的孩子提供实验室旅行和机会，以参与简单的实验。在非洲和太平洋之下，地球深层内部最神秘的大型低剪力波速度（LLSVP）是地球深层内部最神秘的方面。这些省的起源，组成和动态仍然存在争议。例如，已经提出，LLSVPS的边缘主要形成羽毛，而LLSVPS的夹带材料解释了某些热点处发现的不同化学不对称。 PI提出了一项实验流体动力学研究，以探讨三个提出的LLSVP结构如何控制并与地幔羽相互作用。这三个结构代表了到目前为止提出的LLSVP形成假设的范围：a）纯热热； b）致密和变形； c）不可辨别的和未耦合。他们将使用最先进的可视化工具，包括扫描粒子图像速度计和温度计来测量三维温度和流场，激光诱导的荧光以及拉格朗日分析工具来定位羽毛并量化夹带到非常高的空间和时间分辨率。 PI寻求测试位置控制以及边缘的夹带是否解释了热点熔岩中观察到的化学不对称性。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子和更广泛的影响来审查标准的评估值得支持的。

项目成果

Ancient helium and tungsten isotopic signatures preserved in mantle domains least modified by crustal recycling

• DOI: 10.1073/pnas.2009663117
• 发表时间: 2020-11
• 期刊: Proceedings of the National Academy of Sciences
• 作者: M. Jackson;J. Blichert‐Toft;S. Halldórsson;A. Mundl‐Petermeier;M. Bizimis;M. Kurz;A. Price;Sunna Harðardóttir;L. Willhite;K. Breddam;T. Becker;R. Fischer

The Mercury Isotopic Composition of Earth's Mantle and the Use of Mass Independently Fractionated Hg to Test for Recycled Crust

• DOI: 10.1029/2021gl094301
• 发表时间: 2021-09-16
• 期刊: GEOPHYSICAL RESEARCH LETTERS
• 影响因子: 5.2
• 作者: Moynier, Frederic;Jackson, Matthew G.;Chen, Jiubin
• 通讯作者: Chen, Jiubin

Mantle plumes and their role in Earth processes

• DOI: 10.1038/s43017-021-00168-6
• 发表时间: 2021-05-25
• 期刊: NATURE REVIEWS EARTH & ENVIRONMENT
• 影响因子: 42.1
• 作者: Koppers, Anthony A. P.;Becker, Thorsten W.;Whittaker, Joanne M.
• 通讯作者: Whittaker, Joanne M.

Chondritic mercury isotopic composition of Earth and evidence for evaporative equilibrium degassing during the formation of eucrites

• DOI: 10.1016/j.epsl.2020.116544
• 发表时间: 2020-12-01
• 期刊: EARTH AND PLANETARY SCIENCE LETTERS
• 影响因子: 5.3
• 作者: Moynier, Frederic;Chen, Jiubin;Day, James Md
• 通讯作者: Day, James Md

Hot and Heterogenous High‐ 3 He/ 4 He Components: New Constraints From Proto‐Iceland Plume Lavas From Baffin Island

热且异质的高 3 He/4 He 成分：来自原始冰岛巴芬岛熔岩熔岩的新限制

• DOI: 10.1029/2019gc008654
• 发表时间: 2019
• 期刊: Geosystems
• 作者: Willhite, Lori N.;Jackson, Matthew G.;Blichert‐Toft, Janne;Bindeman, Ilya;Kurz, Mark D.;Halldórsson, Sæmundur A.;Harðardóttir, Sunna;Gazel, Esteban;Price, Allison A.;Byerly, Benjamin L.
• 通讯作者: Byerly, Benjamin L.