CSEDI: Understanding the influence of mantle dynamics on the generation of Earth's magnetic field throughout the plate tectonics cycle.

CSEDI：了解整个板块构造周期中地幔动力学对地球磁场产生的影响。

基本信息

批准号：
2054605
负责人：
Courtney Sprain
金额：
$ 42.87万
依托单位：
University of Florida
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-15 至 2025-06-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2054605&HistoricalAwards=false
关键词：
CSEDI Understanding influence mantle dynamics

项目摘要

Earth's magnetic field acts as a shield against cosmic radiation and magnetic storms, which can potentially damage technical infrastructure, harm life, and strip away Earth's atmosphere. Understanding the evolution of the magnetic field therefore has important implications for Earth's habitability today and throughout history. An outstanding question that currently limits understanding of the evolution the magnetic field is: When did the solid inner core form? Today, the solidification of the inner core is an important driver of the geodynamo, which generates Earth’s magnetic field. This project seeks to better constrain the timing of inner core formation, which will be accomplished by a unique coupling of mantle convection models to geodynamo simulations that produce Earth-like magnetic fields. The results from this project will have a scientific impact in multiple disciplines, including geodynamics, magnetospheric physics, studies of the deep interior, and the evolution of life. More generally, this project addresses the important question of “How is Earth’s internal field generated?”, which can help to better predict future magnetic field changes that could result in harm to modern technical infrastructure or life itself. Additionally, the proposed work will support two early-career female PIs, build STEM talent by training and educating two undergraduate students and one postdoctoral researcher, improve available scientific infrastructure by releasing the created software as open-source, and will facilitate international exchange with project collaborators in the UK and France. A wide audience will be engaged through a multi-year outreach initiative building on the successful Scientist in Every Florida School program in collaboration with University of Florida Thompson Earth Systems Institute.Because the growth of the inner core is a major driver of the geodynamo today, it can be assumed that inner core nucleation may have caused significant changes in Earth's past magnetic field. But so far, the interpretation of any detectable signal in the paleomagnetic data at the Earth’s surface has remained ambiguous because (1) the precise effects of inner core nucleation on the magnetic field are unknown, and (2) the magnitude of magnetic field variations caused by mantle convection are currently not well constrained. This project will quantify the largest possible influence of mantle heat transport on the magnetic field at Earth’s surface, taking into account the influence of inner core size. This will be accomplished by computing realistic core-mantle boundary heat flux patterns generated by mantle convection models, and coupling them to geodynamo simulations that produce Earth-like magnetic fields as assessed with the Quality of Paleomagnetic Modeling (QPM) criteria, which is currently the only criteria set that assesses if simulations are reproducing Earth’s long-term magnetic field behavior. In contrast to previous studies, these mantle models do not try to recreate the relatively limited timeframe of known plate motions, or apply simplified heat flux patterns for present-day conditions, but instead predict the largest realistic heat flux variations caused by synthetic plate configurations during the cycle of supercontinent formation and dispersal in Earth's past. This work will improve understanding of the mantle’s role in regulating the magnetic field throughout Earth's history. Additionally, this work will determine whether changes in the magnetic field so far ascribed to inner core nucleation could instead partly or completely be explained by mantle dynamics alone. This project connects planetary evolution, mantle convection, the geodynamo, and paleomagnetic data. This wide collaboration will drive significant advances in the understanding of the Earth as one system, not separated into its layers. More generally, this project addresses the science priority question, “How is Earth’s internal field generated?”, released in the National Academies of Science, Engineering and Medicine decadal report for NSF-EAR.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.

地球磁场充当宇宙辐射和磁暴的屏障，这可能会破坏技术基础设施、危害生命并剥夺地球大气层，因此了解磁场的演变对于当今和整个历史上的地球宜居性具有重要意义。目前限制对磁场演化的理解的突出问题是：固体内核何时形成？如今，内核的凝固是地球发电机的重要驱动力，该发电机产生地球磁场。内核形成的时间，这将通过地幔对流模型与产生类地磁场的地球发电机模拟的独特耦合来完成，该项目的结果将对多个学科产生科学影响，包括地球动力学、磁层物理学、更广泛地说，该项目解决了“地球内部磁场是如何产生的？”这一重要问题，这有助于更好地预测未来可能对现代技术造成损害的磁场变化。基础设施或生活此外，拟议的工作还将支持两名职业生涯早期的女性 PI，通过培训和教育两名本科生和一名博士后研究员来培养 STEM 人才，通过开源发布所创建的软件来改善可用的科学基础设施，并将促进国际交流。与英国和法国的项目合作者合作，将通过与佛罗里达大学汤普森地球系统研究所合作的成功的“每个佛罗里达学校的科学家”计划的多年推广计划来吸引广泛的受众。是地球发电机的主要驱动力今天，可以假设内核成核可能引起了地球过去磁场的重大变化，但到目前为止，对地球表面古地磁数据中任何可检测到的信号的解释仍然不明确，因为（1）的精确影响。内核成核对磁场的影响尚不清楚，并且（2）地幔对流引起的磁场变化的幅度目前尚未得到很好的限制。该项目将量化地幔热传输对磁场的最大可能影响。地球表面，考虑到内核尺寸的影响，这将通过计算地幔对流模型产生的真实地核-地幔边界热通量模式，并将其耦合到产生与地球类似的磁场的地球发电机模拟来完成。古地磁模型质量（QPM）标准，这是目前评估模拟是否再现地球长期磁场行为的唯一标准。与之前的研究相比，这些地幔模型并不试图重现相对的情况。已知板块运动的有限时间范围，或应用当前条件的简化热通量模式，而是预测地球过去超大陆形成和扩散周期期间由合成板块配置引起的最大实际热通量变化。此外，这项工作将确定迄今为止归因于内核成核的磁场变化是否可以部分或完全由地幔动力学单独解释。行星演化、地幔对流、地球发电机和古地磁数据的广泛合作将推动对地球作为一个系统（而不是分层）的理解的重大进展。更一般地说，该项目解决了科学优先问题：“地球是如何存在的”。地球内部场产生了？”，在美国国家科学、工程和医学院的 NSF-EAR 十年报告中发布。该奖项是 NSF 的法定使命，并通过使用基金会的智力价值进行评估，被认为值得支持以及更广泛的影响审查标准。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

The role of subduction in the formation of Pangean oceanic large igneous provinces

俯冲在泛古大陆大洋火成岩省形成中的作用

DOI：
10.1144/sp542-2023-12
发表时间：
2023-05
期刊：
Special Publications
影响因子：
0
作者：
Heron, Philip J.;Gün, Erkan;Shephard, Grace E.;Dannberg, Juliane;Gassmöller, Rene;Martin, Erin;Sharif, Aisha;Pysklywec, Russell N.;Nance, R. Damian;Murphy, J. Brendan
通讯作者：
Murphy, J. Brendan

Changes in core-mantle boundary heat flux patterns throughout the supercontinent cycle

整个超大陆旋回中核幔边界热通量模式的变化

DOI：
10.1093/gji/ggae075
发表时间：
2024-02
期刊：
Geophysical Journal International
影响因子：
2.8
作者：
Dannberg, Juliane;Gassmoeller, Rene;Thallner, Daniele;LaCombe, Frederick;Sprain, Courtney
通讯作者：
Sprain, Courtney

An entropy method for geodynamic modelling of phase transitions: capturing sharp and broad transitions in a multiphase assemblage

用于相变地球动力学建模的熵方法：捕获多相组合中的急剧和广泛的转变