FESD Type I: The Dynamics of Earth System Oxygenation

FESD I 型：地球系统氧合动力学

• 批准号: 1338810
• 负责人: Ariel Anbar
• 金额: $ 484.5万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1338810&HistoricalAwards=false
• 关键词: FESD; Type; Dynamics; Earth; System

Oxygen, in the form of the molecule O2, is abundant in the Earth's atmosphere and oceans, where it is vital for all multi-cellular life, including humans. However, O2 was nearly absent from the atmosphere and oceans during the first half of Earth's history. In the past decade, we solidified our understanding of when the prolonged and complex transition to the modern, O2-rich environment began. However, the cause of this so-called "Great Oxidation Event" (GOE) and later changes in O2 remains one of the major mysteries in Earth System Science. Solving it is of more than academic interest because it will help us understand how the Earth supports life, and provide insights and perspective on some of the environmental challenges posed by human activity. This project will tackle this challenge by combining new data and calculations that reach from the Earth's core to the top of the atmosphere to develop a comprehensive model of the geochemical cycle of O2 that can explain the GOE.The specific research program is motivated by an emerging consensus that biological O2 production began long before the GOE. If so, then the GOE was most likely triggered by a change in O2 consumption. Various lines of reasoning point to changes in the flux of O2-reactive material from the Earth's mantle, perhaps driven by the gradual but inexorable cooling of the planet's interior. However, the specific changes and their causes are unclear and debated. The project team will refine and test a number of hypotheses proposed in the past decade. To do so it necessarily integrates: models of atmospheric chemistry; records of Earth's surface O2 history developed from inorganic and organic geochemical proxies; laboratory calibrations of these proxies; geochemical analyses of samples from the lithosphere and mantle; seismic reconstructions of Earth's interior structure; geodynamic models of mantle mixing and evolution; thermodynamic calculations; and findings from mineral physics experiments. Researchers in these disciplinary communities rarely collaborate. Therefore, the work will be scientifically transformative.The project team aims to extend this transformation beyond its members and even beyond the geosciences. In addition to the typical training and dissemination activities, we will foster communication and integration across disciplinary boundaries by: conducting open, online "workshops without walls" on the O2 puzzle; perform scholarly research into our collaborative research challenges and practices to identify and disseminate best practices for transdisciplinary team science; and develop, deploy, and assess a teacher professional development (PD) program centered on how scientists communicate across diverse disciplinary divides to answer complex questions. These broader activities, together with the science research program, will advance a holistic vision of the Earth System that, while of broad societal importance, is often discussed but rarely realized.

氧气以分子O2的形式在地球的大气和海洋中丰富，在包括人类在内的所有多细胞生活至关重要。但是，在地球历史的上半年，大气和海洋几乎没有O2。在过去的十年中，我们巩固了人们对何时开始延长现代，富含O2的环境的何时开始的理解。但是，这一所谓的“氧化事件”（GOE）的原因和后来的O2变化仍然是地球系统科学的主要奥秘之一。解决它的远远超出了学术兴趣，因为它将帮助我们了解地球如何支持生命，并就人类活动带来的某些环境挑战提供见解和观点。该项目将通过结合从地球核心到大气顶部的新数据和计算来应对这一挑战，从而开发了可以解释GOE的地球化学周期的全面模型。特定的研究计划是由生物O2生产早在GOE之前开始的新兴共识而激发的。如果是这样，那么The Goe很可能是由O2消耗的变化触发的。各种推理指标表明，地球上的O2反应性材料的通量变化，也许是由地球内部逐渐但不可分割的冷却驱动的。但是，具体的变化及其原因尚不清楚和辩论。项目团队将在过去十年中完善并测试许多提出的假设。为此，它一定是：大气化学模型；地球表面O2历史的记录是由无机和有机地球化学代理发展的；这些代理的实验室校准；来自岩石圈和地幔样品的地球化学分析；地震重建地球室内结构；地幔混合与进化的地球动力学模型；热力学计算；以及矿物质实验的发现。这些学科社区的研究人员很少合作。因此，这项工作将是科学的变革性的。项目团队旨在将这种转变扩展到其成员甚至地球科学之外。除了典型的培训和传播活动外，我们还将在纪律界面促进跨纪律界面的交流和集成：在O2难题上进行开放的在线“无墙壁研讨会”；对我们的合作研究挑战和实践进行学术研究，以识别和传播跨学科团队科学的最佳实践；并开发，部署和评估教师专业发展（PD）计划，该计划的重点是科学家如何在各种纪律间进行沟通以回答复杂问题。这些更广泛的活动以及科学研究计划将对地球体系进行整体愿景，尽管社会重要性广泛，但经常被讨论，但很少见到。